Parasciadicleithrum octofasciatum n. gen., n. sp. (Monogenoidea: Dactylogyridae), parasite of Rocio octofasciata (Regan) (Cichlidae: Perciformes) from Mexico characterised by morphological and molecular evidence

Accepted Manuscript Parasciadicleithrum octofasciatum n. gen., n. sp. (Monogenoidea: Dactylogyridae), parasite of Rocio octofasciata (Regan) (Cichlidae: Perciformes) from Mexico characterised by morphological and molecular evidence

Carlos A. Mendoza-Palmero, Isabel Blasco-Costa, David Hernández-Mena, Gerardo Pérez-Ponce de León PII: DOI: Reference:

S1383-5769(16)30416-0 doi: 10.1016/j.parint.2017.01.006 PARINT 1629

To appear in:

Parasitology International

Received date: Revised date: Accepted date:

3 October 2016 11 January 2017 12 January 2017

Please cite this article as: Carlos A. Mendoza-Palmero, Isabel Blasco-Costa, David Hernández-Mena, Gerardo Pérez-Ponce de León , Parasciadicleithrum octofasciatum n. gen., n. sp. (Monogenoidea: Dactylogyridae), parasite of Rocio octofasciata (Regan) (Cichlidae: Perciformes) from Mexico characterised by morphological and molecular evidence. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Parint(2017), doi: 10.1016/j.parint.2017.01.006

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ACCEPTED MANUSCRIPT Parasciadicleithrum octofasciatum n. gen., n. sp. (Monogenoidea: Dactylogyridae), parasite of Rocio octofasciata (Regan) (Cichlidae: Perciformes) from Mexico characterised by morphological and molecular evidence Carlos A. Mendoza-Palmero1*, Isabel Blasco-Costa2, David Hernández-Mena1, Gerardo

Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de

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Pérez-Ponce de León1.

Natural History Museum of Geneva, P.O. Box 6134, CH-1211, Geneva, Switzerland.

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México, Apartado Postal 70-153, Código Postal 04510, México, D. F., Mexico.

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* Corresponding author: Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Apartado Postal 70-153, Código Postal 04510, México, D.

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F., Mexico. Email: [email protected]

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ACCEPTED MANUSCRIPT Abstract Based on an integrative taxonomic approach, combining morphological characters and partial sequences of the 28S rRNA gene, a new genus and species, Parasciadicleithrum octofasciatum, is proposed to accommodate dactylogyrids infecting the gills of Rocio octofasciata (Cichlidae) from a tributary of the Lacantún River basin, Chiapas State, southern Mexico. Morphologically, the new genus resembles members of Sciadicleithrum

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(Dactylogyridae) in the presence of membranes on the anterior margins of both ventral and

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dorsal haptoral bars. However, Parasciadicleithrum octofasciatum n. sp. shows

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morphological differences with respect to a subset of species of Sciadicleithrum occurring in the same host group and geographic area, such as the body size and gonad dimensions

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(length and width of germarium and testis, respectively, smaller in the new genus). Phylogenetic analyses performed herein based on Maximum Likelihood and Bayesian

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Inference criteria, showed that Parasciadicleithrum octofasciatum n. sp. represents an undescribed taxon morphologically very similar to species of Sciadicleithrum from which it

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can be consistently distinguished on the basis of molecular data. P. octofasciatum n. sp. appeared genetically distant from Sciadicleithrum spp. and nested with dactylogyrid

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parasites of African cichlids. Parasciadicleithrum n. gen. showed divergence levels in the 28S rDNA sequences of 25-26 % with respect to Sciadicleithrum spp. Therefore, on the

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basis of molecular evidence mainly, and morphological differences highlighted above, the erection of the new genus is proposed. The evolutionary and ecological factors that may

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have influenced the associations between Neotropical cichlids and their dactylogyrid

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parasites are briefly discussed.

Keywords

Neotropical cichlids; phylogeny; convergent evolution; Dactylogyridae; Mexico

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ACCEPTED MANUSCRIPT 1. Introduction Neotropical fish of the family Cichlidae (Perciformes) are highly diverse with over 500 species distributed from northern Patagonia in Argentina up to northern Mexico [1]. Approximately 205 helminth species have been recorded from about 295 species of cichlids across the Americas with trematodes and monogenoids as the most species-rich groups [2]. American cichlids harbour a diverse monogenoidean fauna represented by 46 species, of

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which the genus Sciadicleithrum Kritsky, Thatcher et Boeger, 1989 is the most diverse with

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26 species, followed by Gussevia Kritsky, Thatcher et Boeger, 1986 with 17 species,

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Trinidactylus Hanek, Molnar et Fernando, 1974 and Tucunarella Mendoza-Franco, Scholz et Rozkošná, 2010 with one species each (all belonging to the Dactylogyridae), and

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Gyrodactylus geophagensis Boeger et Popazoglo, 1995 (Gyrodactylidae) as the only gyrodactylid currently described on Neotropical cichlids [2,3–5] (Vanhove et al. [2] listed

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49 species in their inventory including African monogenoids introduced to America with their hosts).

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In Mexico, in the last two decades, 51 of 54 species of cichlids distributed in hydrological systems across the country (representing 94% of all cichlids registered in

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Mexico) have been studied with relative intensity for parasitic helminths [6,7]. However, only four species of the Dactylogyridae (formally described) and three unidentified

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gyrodactylids have been recorded in Mexican cichlids: S. bravohollisae Kritsky, VidalMartínez et Rodríguez-Canul, 1994 (infecting 16 fish species), S. meekii Mendoza-Franco,

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Scholz et Vidal-Martínez, 1997 (in five fish species), S. mexicanum Kritsky, VidalMartínez et Rodríguez-Canul, 1994 (in 12 fish species) and S. splendidae Kritsky, Vidal-

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Martínez et Rodríguez-Canul, 1994 (in five fish species). The species S. bravohollisae, S. meekii and S. mexicanum have been also reported from other areas in Middle-America [8– 10].

In the present study, further examination of helminth parasites of cichlids revealed the presence of monogenoids on the gills of Rocio octofasciata (Regan) from Chiapas State, southern Mexico. Morphology of haptoral elements of these dactylogyrids, in particular that of ventral and dorsal bars, showed a close resemblance with Sciadicleithrum spp. In order to evaluate the phylogenetic relationships of the specimens found on R. octofasciata with respect to other species of Sciadicleithrum and members of the Dactylogyridae,

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ACCEPTED MANUSCRIPT analyses of molecular sequences of a partial fragment of the 28S rRNA gene were performed based on Maximum Likelihood and Bayesian Inference criteria. Molecular analysis was instrumental to recognise that the specimens from Rocio octofasciata required the erection of a new genus to accommodate the new species that is morphologically and molecularly characterised herein.

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2. Material and Methods

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2.1. Specimen collection

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Five specimens (all juveniles with total length ranging between 5 and 8 cm) of Rocio octofasciata (Regan) were collected using seine nets in an unnamed creek at Ejido

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Reforma Agraria, Municipio Marqués de Comillas, a tributary of the Lacantún River basin, Chiapas, Mexico (16º13'11''N; 90º50'34''W). Fish were transported alive to the laboratory

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and kept in plastic containers with aeration until examination. Fish were killed via spinal cord severance and immediately examined for ectoparasites. Gill arches were removed,

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placed in Petri dishes with tap water, and studied individually under a stereomicroscope. Monogenoids were fixed in a mixture of glycerine-ammonium picrate (GAP) [11] in order

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to study their sclerotized structures. After their morphological evaluation, these specimens were mounted as permanent slides with Canada balsam according to the procedure of

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Ergens [12]. Other individuals were fixed in hot water (~80ºC) and kept in vials with 95% ethanol for morphology and molecular analyses. For morphological analysis, some of these

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specimens were stained with Gomori’s trichrome and mounted in Canada balsam to study their internal anatomy.

2.2. Morphological analyses

All measurements provided are in micrometres and represent the greatest distance between extreme points. Measurements are presented as the mean followed by the range and number of specimens measured (n) in parentheses. Drawings were made with the aid of an Olympus BX51 (Olympus, Japan) microscope equipped with a drawing tube.

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ACCEPTED MANUSCRIPT Numbering of hook pairs followed Mizelle [13]. Direction of the male copulatory organ (MCO) was determined according to Kritsky et al. [14]. Microphotographs were taken with a Zeiss optical microscope equipped with phase contrast device. Type, voucher specimens and hologenophores [15,16] were deposited in the Colección Nacional de Helmintos (CNHE), Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Mexico, the Natural History Museum of Geneva, Switzerland (MHNG) and in the

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helminthological collection of the Institute of Parasitology, České Budějovice, Czech

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Republic (IPCAS), as indicated in the species description. A symbiotype of Rocio

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octofasciata was deposited in the Colección Nacional de Peces (CNPE 20261), Instituto de Biología, UNAM. For comparative purposes, the following type and voucher specimens

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were studied: Sciadicleithum bicuense Vidal-Martínez, Scholz et Aguirre-Macedo, 2001 (CNHE 4163 [holotype]), S. bravohollisae (CNHE 6057-8, 6065-6, 7109-11, 7114 [25

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vouchers]), S. ergensi Kritsky, Thatcher et Boeger, 1989 (Instituto Nacional de Pesquisas da Amazônia [INPA] 161 [holotype], Harold W. Manter Laboratory (HWML) 20729 [three

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paratypes]), S. iphthium Kritsky, Thatcher et Boeger, 1989 (INPA 157 [holotype], INPA 158a–h [eight paratypes], HWML 20272 [four paratypes]), S. maculicaudae Vidal-

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Martínez, Scholz et Aguirre-Macedo, 2001 (CNHE 4164 [holotype]), S. meekii (CNHE 2915 [holotype]), S. mexicanum (CNHE 3896, 4141 [three vouchers]), S. nicaraguense

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Vidal-Martínez, Scholz et Aguirre-Macedo, 2001 (CNHE 4162 [holotype], 3895 [four vouchers]), S. panamensis Mendoza-Franco, Aguirre-Macedo et Vidal-Martínez, 2007

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(CNHE 5790 [holotype], 5791 [two paratypes], S. splendidae (CNHE 3720, 3721 [two vouchers]) and S. uncinatum Kritsky, Thatcher et Boeger, 1989 (INPA 162, 163 [holotype

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and paratype, respectively], HWML 20730 [three paratypes]). Scientific host name followed the proposal of Schmitter-Soto [17].

2.3. DNA extraction, amplification and sequencing

Molecular characterisation of specimens followed the procedure described by Mendoza-Palmero et al. [16] with slight modifications. Individual specimens were digested in a solution containing 10 mM Tris-HCl (pH 7.6), 200 mM NaCl, 0.5 M EDTA (pH 8.0), 10% Sarkosyl, 0.1 mg/ml proteinase K and H2O (100 µl per sample) during three hours at

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ACCEPTED MANUSCRIPT 56ºC. Posteriorly, the proteinase was denatured at 95º C for 15 min. Genomic DNA was extracted using DNAzol® (Molecular Research Centre, Cincinnati, Ohio) according to manufacturer instructions. Polymerase chain reaction (PCR) amplifications were performed in 25 µl reactions containing 2.5 µl of extraction supernatant (~10–20 ng of template DNA), and 0.4 µM of each PCR primer. Partial 28S rDNA fragments (D1–D3) were amplified using primers U178 (5'-GCA CCC GCT GAA YTT AAG-3') and L1642 (5'-CCA

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GCG CCA TCC ATT TTC A-3') [18]. The following thermocycling profile was utilized:

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denaturation of DNA (95°C for 3 min); 34 cycles of amplification (94°C for 30 s, 56°C for

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30 s and 72°C for 90 s); and a final extension hold for 4 min at 72°C. PCR products were purified prior to sequencing using exonuclease I and shrimp alkaline phosphatase enzymes

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[19]. Amplicons were cycle-sequenced from both strands with PCR primers and L1200R (5'-GCA TAG TTC ACC ATC TTT CGG-3') [20], using an ABI BigDye™ Terminator

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v3.1 Ready Sequencing Kit, alcohol-precipitated and run on an ABI 3730xl Genetic Analyser (Applied Biosystems). Contiguous sequences were assembled and edited using

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Geneious® (Biomatters Ltd. v. 8.1) and submitted to GenBank (28S rDNA, KY305878–

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KY305891).

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2.4. Alignment and phylogenetic analyses

Fourteen newly generated sequences for the 28S rDNA fragment (900–1,500 bp

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long) of five dactylogyrid species were aligned together with published sequences from GenBank of 62 species belonging to the subfamilies Ancylodiscoidinae, Ancyrocephalinae,

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Dactylogyrinae and Pseudodactylogyrinae of the Dactylogyridae (see Table 1). Representative sequences of nine species belonging to the families Monocotylidae, Diplectanidae, Pseudomurraytrematidae and Tetraonchidae were used as outgroups (see [16] and Table 1). Sequences were aligned using default parameters of MAFFT implemented in Guidance [21] and the extremes of the alignment were trimmed to match the shortest sequence. Two 28S datasets were retained for phylogenetic analyses; a full dataset including all sequences and nucleotide positions (673 bp) as obtained from MAFFT and a stringent alignment (535 bp) in which nucleotide positions with an alignment score below 0.5 were excluded [22]. Phylogenetic analyses were run under Maximum Likelihood

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ACCEPTED MANUSCRIPT (ML) and Bayesian inference (BI) criteria, employing the models of nucleotide evolution GTR+Γ+I and GTR+Γ for the full and stringent datasets, respectively (estimated using jModelTest 2.1.1 [23,24]). ML analyses were conducted using the program RAxML v. 7.3 [25,26]. All model parameters and bootstrap support values (1,000 repetitions) were estimated using RAxML. BI trees were constructed using MrBayes v. 3.2 [27], running two independent MCMC runs of four chains for 10 million generations and sampling tree

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topologies every 1000 generations. Burn-in periods were set to the first 2500 generations. A consensus topology and nodal support estimated as posterior probability values [28] were

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calculated from the remaining trees. All MrBayes and RAxML analyses were performed on the computational resource CIPRES [29]. Genetic divergences were calculated as

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uncorrected p-distances using MEGA v.6 [30].

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3. Results

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3.1. Morphological characterisation of the new genus

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3.1.1. Parasciadicleithrum n. gen. (Fig. 1A–G)

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Diagnosis: Monogenoidea, Dactylogyridae. Body fusiform, comprising cephalic region, trunk, peduncle and haptor. Tegument smooth. Four cephalic lobes; three pairs of cephalic

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organs, one apical, two bilateral; cephalic glands inconspicuous. Eyespots four. Mouth subterminal, midventral; pharynx muscular, glandular; oesophagus short; intestinal caeca

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two, confluent posterior to gonads; lacking diverticula. Common genital pore midventral at level of intestinal bifurcation. Gonads intercaecal, overlapping; germarium ventral to testis. Vas deferens not observed; seminal vesicle a simple dilation of vas deferens, delicate. Copulatory complex comprising male copulatory organ (MCO) and accessory piece. MCO tubular with less than two clockwise rings. Accessory piece serving as guide for distal portion of MCO, not articulated to MCO base. Seminal receptacle pre-germarial; vaginal opening not observed. Vitellaria scattered throughout trunk. Peduncle short. Haptor armed with dorsal and ventral anchor/bar complexes, ventral and dorsal bars with delicate membranes on their anterior margin; seven pairs of similar and unmodified hooks. Hook

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ACCEPTED MANUSCRIPT distribution: four ventral and two dorsal pairs [13]. Parasites of Neotropical cichlids. Typespecies Parasciadicleithrum octofasciatum n. sp.

3.1.1.1. Parasciadicleithrum octofasciatum n. sp.

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3.1.1.2 Morphological description (Fig. 1A–G)

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Diagnosis based on 22 specimens fixed in GAP and 24 fixed in hot water and stained with

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Gomori’s trichrome (measurements are given in Table 2): Body fusiform, greatest width at level of germarium. Cephalic margin broad; cephalic lobes well developed, 3 bilateral pairs

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of head organs; cephalic glands indistinct. Eyespots four, few accessory granules scattered in cephalic region. Pharynx subspherical, oesophagus short, intestinal caeca confluent

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posterior to gonads. Peduncle short; haptor octagonal. (Fig. 1A). Ventral anchor with drastically reduced superficial and deep roots, evenly curved shaft and point, not exceeding

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base width (Fig. 1B); dorsal anchor with well-developed superficial root, heavily reduced deep root, evenly curved shaft and point, not exceeding base width (Fig. 1C). Ventral bar

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V-shaped, robust, with expanded ends and delicate membranes on the anterior margin (Fig. 1D). Dorsal bar open V-shaped, ends slightly expanded laterally, delicate membranes on

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anterior margin (Fig. 1E). Hooks similar in shape and size; with straight shaft and curved point, protruding thumb, shank proximally expanded, filamentous hooklet (FH) loop

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approximately of shank length (Fig. 1G). MCO comprised of short tube with circular base forming 1½ clockwise rings (Fig. 1F). Accessory piece P-shaped, short and delicate,

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serving as guide of MCO distally (Fig. 1F). Gonads overlapped; testis dorsal to germarium (only observed in three specimens); vas deferens not observed, seminal vesicle small, delicate, located posterior to MCO. Prostatic glandular mass dorsal to MCO. Germarium small, ventral to testis; oviduct and ootype not observed, proximal region of uterus located anterior to seminal receptacle, distal part of uterus not clearly observed. Vaginal aperture not observed. Seminal receptacle semispherical, located anterior to germarium. Vitelline follicles dense, scattered throughout trunk, absent in region of reproductive organs.

3.1.2. Taxonomic summary

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Type-host: Rocio octofasciata (Regan) (Cichlidae: Perciformes). Type-locality: unnamed creek at Ejido Reforma Agraria, Municipio Marqués de Comillas, tributary of the Lacantún River basin, Chiapas, Mexico (16º13'11''N; 90º50'34''W). Site on host: Gills. Prevalence: 5/5 = 100%.

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Intensity: 1–25 parasites per host infected.

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Other monogenoidean species found on R. octofasciata in this study: Sciadicleithrum

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mexicanum and Gyrodactylus sp. 3 sensu Vidal-Martínez et al. [6].

Specimens deposited: Holotype (CNHE 10023), 11 paratypes (CNHE 10024) and 11

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vouchers (CNHE 10025), 3 paratypes (MHNG-PLAT-94132), 1 voucher (MHNG-PLAT94133) and 5 vouchers (IPCAS M-564). Specimens of S. mexicanum (3 vouchers; CNHE

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10026) and Gyrodactylus sp. 3 (1 voucher; CNHE 10027) were also deposited. Hologenophores [15] were deposited in the CNHE under the following catalogue numbers:

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Parasciadicleithrum octofasciatum (4 slides; CNHE 10028), S. meekii (6 slides; 10296– 10297), S. mexicanum (4 slides; 10029) and S. splendidae (3 slides; 10030).

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Etymology: The genus name refers to the resemblance of the new taxon to Sciadicleithrum Kritsky, Thatcher et Boeger, 1989, whose members also parasitise Neotropical cichlids, and

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3.1.2.1. Remarks

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the specific epithet is based on the name of the host.

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Of all dactylogyrid genera recorded on Neotropical cichlids, Parasciadicleithrum n. gen. resembles Sciadicleithrum most closely, mainly in the morphology of the haptoral armament with shared presence of membranes on the anterior margin of both ventral and dorsal bars. Indeed, there are no diagnostic features that unequivocally distinguish the new genus from Sciadicleithrum. However, there are some morphological differences between Parasciadicleithrum octofasciatum n. sp. and a set of species of Sciadicleithrum from the same geographic region namely S. bravohollisae, S. meekii, S. mexicanum and S. splendidae that can be used to distinguish between the two genera, such as size and shape of some internal organs and body size. In P. octofasciatum n. sp., the germarium and testis

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ACCEPTED MANUSCRIPT are comparatively much smaller than those of species of Sciadicleithrum, (Fig. 2A–E and Table 2). The seminal vesicle in P. octofasciatum n. sp. is also significantly smaller than those of S. bravohollisae, S. meekii, S. mexicanum and S. splendidae (not illustrated). This feature was extremely difficult to observe in P. octofasciatum n. sp. due to its small size and does not show thick walls (observed in stained specimens) as in those of the species mentioned above. Parasciadicleithrum octofasciatum n. sp., the type and only species of

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the new genus, is comparatively shorter than most species of Sciadicleithrum. In fact, the

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new species represents one of the smallest dactylogyrids recorded infecting Neotropical

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cichlids, with a body length range of 146–275 µm, while body length in S. frequens Bellay, Takemoto, Yamada et Pavanelli, 2008 from Brazil varied from 67 to 363 µm, 192–265 in S.

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meekii and 250 in S. splendidae (both species from Mexico) and 269–320 in S. nicaraguense from Nicaragua [31–33]. Notwithstanding the above differences, we

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acknowledge that internal organs and body size dimensions can vary on the basis of sampling and fixation procedures and that is why, at the moment, only molecular characters

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are reliable to distinguish the two genera.

Additionally, we observed that haptoral anchors and bars of specimens of P.

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octofasciatum n. sp. did not show evident morphological differences in comparison to Sciadicleithrum spp. recorded in Mexican cichlids such as S. bravohollisae, S. meekii, S.

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mexicanum and S. splendidae (see Fig. 3 [A–E]). Therefore, given the shared morphological similarity between P. octofasciatum n. sp. and Sciadicleithrum spp., the

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analyses.

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proposal of the new genus is based mainly on the results of the molecular phylogenetic

3.1.2.2. Phylogenetic position of Parasciadicleithrum octofasciatum n. sp.

Phylogenetic hypotheses based on the full alignment of partial sequences of the 28S rRNA gene and the stringent dataset including only positions in the alignment with a score higher than 0.5 showed congruent results in regard to the placement of the specimens sequenced from R. octofasciata and Sciadicleithrum spp. within clade B (sensu MendozaPalmero et al. [16]) and herein (Fig. 4, clade marked in blue) comprising mostly marine dactylogyrids in the phylogeny. Sciadicleithrum bravohollisae, S. meekii, S. mexicanum

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ACCEPTED MANUSCRIPT and S. splendidae formed a strongly supported monophyletic clade sister to a group of marine species contained in the genera Euryhaliotrematoides, Euryhaliotrema and Aliatrema, although the relationships among them were weakly supported in both BI and ML analyses, and varied depending on the dataset considered. Strikingly, irrespective of morphological resemblance, sequenced specimens of P. octofasciatum n. sp. appeared genetically distant from Sciadicleithrum spp. in all analyses, and were nested within a clade

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of African freshwater species of Cichlidogyrus and Scutogyrus, and marine species of

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Metahaliotrema, Haliotrematoides and Protogyrodactylus (Fig. 4). ML analyses showed P.

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octofasciatum n. sp. as the sister species of Cichlidogyrus and Scutogyrus, but nodal support for their relationship was relatively strong only in the full dataset analysis (80%

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bootstrap support). The morphological similarity between P. octofasciatum n. sp. and Sciadicleithrum spp. along with the results yielded by both phylogenetic analyses, indicate

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that the monotypic P. octofasciatum n. sp. in fact represent a genus genetically distant but

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morphologically similar to species of Sciadicleithrum.

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3.2. Genetic divergence

Genetic divergence in the 28S rDNA sequences among Sciadicleithrum spp. ranged

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between 1 and 6 %, whereas divergence between Sciadicleithrum and the most closely related genera (Aliatrema, Euryhaliotrema and Euryhaliotrematoides) spanned from 13 to

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16%. Parasciadicleithrum n. gen showed divergence levels of 25-26% with respect to Sciadicleithrum spp., despite their morphological resemblance. Parasciadicleithrum

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octofasciatum n. sp. was also highly divergent from the closest phylogenetically related genera (as mentioned above), 20 to 25%. The erection of the new genus and species is then supported as follows: 1) the position of these newly sequenced specimens from R. octofasciata within the dactylogyrids phylogeny and 2) their high genetic divergence from the phylogenetically related genera Cichlidogyrus, Scutogyrus, Metahaliotrema, Haliotrematoides, Protogyrodactylus and the morphologically similar Sciadicleithrum.

3.2.1. Note on the taxonomic status of Sciadicleithrum maculicaudae

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ACCEPTED MANUSCRIPT In our morphological evaluation of the holotype of S. maculicaudae (CNHE 4164) described by Vidal-Martínez et al. [9] from Paraneetroplus maculicaudae (Regan) (type host) from Nicaragua, we found that this species shares the following morphological characteristics with S. bravohollisae: presence of L-shaped MCO comprising less than one ring, ventral anchors with strongly reduced roots and wide base, dorsal anchors with elongated superficial roots, vagina with double cup-shaped sclerotized aperture, V-shaped

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ventral bar with expanded ends (see Fig. 5), and the presence of two lenses associated with

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the posterior pair of eyespots (not illustrated). These characteristics along with the

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measurements of the sclerotized structures taken from the holotype of S. maculicaudae and those obtained from voucher specimens of S. bravohollisae (see Table 2) make us think

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that specimens described as S. maculicaudae most probably correspond to S. bravohollisae. In a recent parasitological survey, we examined a single specimen of P. maculicaudae

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(adult, TL 25 cm), type host of S. maculicaudae, from the Torsuani River, Nicaragua (unpublished data), which is in fact 24 km south from the type locality (Caño Marañón)

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where S. maculicaudae was described and only S. bravohollisae and S. mexicanum were found on the gills of P. maculicaudae. However, to corroborate the possible synonymy

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between S. maculicaudae and S. bravohollisae, we advise the following: 1) to obtain additional dactylogyrid specimens from a representative number of P. maculicaudae from

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the type host and locality, and 2) to obtain sequences of these dactylogyrids and compare

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4. Discussion

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them with those of S. bravohollisae newly provided herein.

4.1. Dactylogyrid fauna on Mexican cichlids

With our updated parasitological data, the dactylogyrid fauna of Mexican cichlids is now composed of five species, i.e., Sciadicleithrum bravohollisae, S. meekii, S. mexicanum, S. splendidae and Parasciadicleithrum octofasciatum n. sp. The species S. splendidae and P. octofasciatum n. sp. are so far restricted to particular hydrological systems in southern Mexico (S. splendidae has been registered in Quintana Roo and Yucatan States and in tributaries of the Usumacinta River basin and P. octofasciatum n. sp. has been found only

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ACCEPTED MANUSCRIPT in the latter basin), while S. bravohollisae, S. meekii and S. mexicanum have a broader geographical distribution, being recorded in Guatemala and Nicaragua [8-10]. Additionally, Mendoza-Franco et al. [34] identified an undescribed species of Cacatuocotyle Boeger, Domingues et Kritsky, 1997 (Dactylogyridae) that Vidal-Martínez et al. [6] found in Parachromis friedrichsthalii (Heckel) from Quintana Roo, Mexico and recorded as Ancyrocephalinae gen. sp. However, members of Cacatuocotyle are parasites primarily of

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Neotropical characid fish (Characiformes) [4,35,36], therefore the presence of

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Cacatuocotyle sp. in cichlids may represent an accidental infection [34].

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Other dactylogyrids have been recorded from the same locality where we conducted our research, i.e., Reforma Agraria, Lacantún River basin, Chiapas, Mexico. Salgado-

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Maldonado et al. [37] examined a total of 20 species of cichlids from this locality and the dactylogyrids S. mexicanum on “Cichlasoma” trimaculatum (Günther) and Amphilophus

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macracanthus (Günther), S. meekii on Thorichthys meeki Brind and Sciadicleithrum sp. on Petenia splendida Günther were recorded. These authors mentioned that voucher

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specimens of each helminth parasite recorded in their study were deposited in the Colección Nacional de Helmintos (CNHE, UNAM). However, no specimen of those

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species of Sciadicleithum was deposited in that collection (L. García-Prieto, personal communication). Therefore, we could not compare specimens of Parasciadicleithrum

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octofasciatum n. sp. with those previously collected specimens from the same locality and

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adjacent areas, in particular to the unidentified species of Sciadicleithrum.

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4.2. Parasite-host association among dactylogyrids infecting cichlids

While the phylogenetic relationships of monogenoidean fauna of African cichlids have been investigated even before the availability of molecular approaches [38–43], their Neotropical counterparts have been largely ignored. To date, a single study assessed the intrageneric relationships between 16 species of Sciadicleithrum spp. described up to 2005, on the basis of morphological characters [44]. That analysis showed that the four species of Sciadicleithrum in Middle-American cichlids form a more recently derived monophyletic group along with one species from Central America [44], and this was consistent with the hypothesis of a colonization event of species found in Middle-America from South

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ACCEPTED MANUSCRIPT American cichlids (see [45]). Interestingly, the cladistic analysis performed by MendozaFranco and Vidal-Martínez [44] shows S. bravohollisae and S. maculicaudae (a possible case of synonymy) as sister species, with a close morphological similarity. The molecular phylogeny provided in this study is the first to include Neotropical members of ectoparasitic dactylogyrids infecting cichlids. Our findings illustrate what Vanhove et al. [2] recently suggested, in that these monogenoids belong to the same genera

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within continents and differ at the genus level between continents. As an example, species

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of Cichlidogyrus are limited to Africa and the Middle East whereas species of

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Sciadicleithrum are exclusively found in the Neotropics. Our phylogenetic analyses showed that four species of Sciadicleithrum (S. bravohollisae, S. meekii, S. mexicanum and S.

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splendidae) represent a monophyletic group closely related to marine taxa occurring mostly in percomorphs across the Pacific Ocean. In a previous study carried out on the basis of

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morphology, Pariselle et al. [46] found Sciadicleithrum as sister group of marine Protogyrodactylus. Phylogenetic relationships obtained independently by molecular

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(present study) and morphological [46] datasets support the idea that Middle-American cichlids were secondarily colonised by helminth species from the marine/brackish ancestors

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[2,45,47]. Similarly, the presence of cryptogonimid trematodes in Middle-American cichlids indicates a connection with marine environments based on the fact that

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cryptogonimids are present in marine percomorphs (e.g., lutjanids), and it has been speculated that species of these trematodes in cichlids could have speciated by host-

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switching from such marine and brackish water fish [45,47]. Cichlids show a predominant Gondwanan distribution with sister relationships

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congruent with vicariance scenarios (e.g., Africa and South-America species). However, there is still an on-going debate about the origin of their current geographical distribution [48 and references therein]. The discovery of P. octofasciatum n. sp. and its close phylogenetic affinity to freshwater dactylogyrids of African cichlids points towards shared biogeographic patterns of Gondwanan vicariance for both, cichlids and this clade of freshwater dactylogyrids. Alternatively, the sister relationship of P. octofasciatum n. sp. to African dactylogyrid clades could indicate an introduction of this dactylogyrid together with African species of Oreochromis to the Americas and recent host-switch to American

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ACCEPTED MANUSCRIPT cichlid R. octofasciata. Further, data from coexisting tilapia in this river system and nearby areas could help to rule out the latter hypothesis. Convergent evolution towards parasitizing American cichlids may be responsible for the observed morphological analogies in haptoral structures between P. octofasciatum n. sp. and Sciadicleithrum spp. Irrespective of morphological resemblance, the new species (and genus) is not closely related to Sciadicleithrum, suggesting that the parasite

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community of Middle-American cichlids is composed by species resulting from both;

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association by descent and association by colonisation. Our results shed some light on the

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evolutionary and biogeographical history of this host-parasite association, as pointed out by Vanhove et al. [2] and Pariselle et al. [46], and provides the grounds for future studies

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aimed at testing the monophyly of the genus Sciadicleithrum, in which 26 species have

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been recognized thus far [2,4–5].

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5. Conclusion

This study emphasises the need of using DNA sequences and an integrative

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taxonomic approach for accurate species and genera delimitation and classification in dactylogyrids. Molecular data were instrumental in this case to establish reciprocal

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monophyly and levels of genetic divergence to support the recognition of the new described species and to establish its phylogenetic position within the phylogeny of the

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Dactylogyridae. Also, molecular data were crucial to show that specimens collected from R. octofasciata in fact represented an undescribed genus that can only be confidently

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distinguished from sympatric dactylogyrids (Sciadicleithrum spp.) infecting Neotropical cichlids on molecular basis. Furthermore, molecular analyses performed herein demonstrated that the morphological similarity of Parasciadicleithrum octofasciatum n. sp. with species of Sciadichleithrum represents a case of convergent evolution. The proposal of P. octofasciatum n. sp. is a clear example that integrative taxonomy is a powerful tool that should be considered for the accurate establishment of new taxa, especially when the traditional taxonomic approaches cannot identify morphological convergences between species or genera, leading to potentially erroneous estimates of helminth species richness in several groups of vertebrates.

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Acknowledgements

The authors are indebt to the authorities of Ejido Reforma Agraria, Chiapas and Brenda Solórzano-García (Instituto de Biología, UNAM) for their support during the fieldwork. Luis García-Prieto (CNHE, Instituto de Biología, UNAM), Celio Magalhães (Coleção de

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Invertebrados, Instituto Nacional de Pesquisas da Amazônia, Brazil) and Scott L. Gardner

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(University of Nebraska State Museum, USA) kindly lent us type and voucher specimens

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under their care. Armando Martínez and Carlos Jordán (CNPE, Instituto de Biología, UNAM) identified and catalogued the fishes, Laura Márquez-Valdelamar (Instituto de

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Biología, UNAM) gave us support with sample sequencing, Berenit Mendoza-Garfias (Instituto de Biología, UNAM) helped with the microphotographs and Juan J. Schmitter-

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Soto (Colegio de la Frontera Sur, Mexico) provided valuable literature on cichlids. Comments and suggestions from two anonymous reviewers are also greatly appreciated.

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CAMP thanks to the Coordinación de la Investigación Científica and Dirección General de Asuntos de Personal Académico (DGAPA), UNAM, Mexico for the postdoctoral

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fellowship granted. This study was financially supported by the Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica PAPIIT-UNAM IN204514 granted to

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GPPL.

16

ACCEPTED MANUSCRIPT References S.O. Kullander, A phylogeny and classification of the South American Cichlidae (Teleostei: Perciformes), in: L.R. Malabarba, R.E. Reis, R.P. Vari, Z.M.S. Lucena, C.A.S. Lucena (Eds.), Phylogeny and Classification of Neotropical Fishes. Edipucrs, Porto Alegre, 1998. pp. 461-498.

[2]

M.P.M. Vanhove, P.I. Hablützel, A. Pariselle, A. Šimková, T. Huyse, J.A.M. Raeymaekers, Cichlids: A host of opportunities for evolutionary parasitology. Trends Parasitol. 32 (2016) 820–832 doi: 10.1016/j.pt.2016.07.002.

[3]

W.A. Boeger, F. Popazoglo, Neotropical Monogenoidea. 23. Two new species of Gyrodactylus (Gyrodactylidae) from a cichlid and an erythrinid fish of Southeastern Brazil, Mem. I. Oswaldo Cruz, 90 (1995) 689–694. doi: 10.1590/S007402761995000600006.

[4]

S.C. Cohen, M.C.N. Justo, A. Kohn, South American Monogenoidea parasites of fishes, amphibians and reptiles, first ed., Fundação Oswaldo Cruz and Conselho Nacional de Desenvolvimiento Científico e Tecnológico, Rio de Janeiro, 2013.

[5]

F. Paschoal, T. Scholz, M. Tavares-Dias, J.L. Luque, Dactylogyrids (Monogenea) parasitic on cichlids from northern Brazil, with descriptions of two new species of Sciadicleithrum and new host and geographical records, Acta Parasitol. 61 (2016) 158–164. doi: 10.1515/ap-2016-0021.

[6]

V.M. Vidal-Martínez, M.L. Aguirre-Macedo, T. Scholz, D. González-Solís, E.F. Mendoza-Franco, Atlas of the helminth parasites of cichlid fish of Mexico, Academia, Prague, 2001.

[7]

G. Pérez-Ponce de León, A. Choudhury, Parasite inventories and DNA-based taxonomy: lessons from helminths of freshwater fishes in a megadiverse country, J. Parasitol. 96 (2010) 236–244. doi: 10.1645/GE-2239.1.

[8]

E.F. Mendoza-Franco, V.M. Vidal-Martínez, L. Aguirre-Macedo, R. RodríguezCanul, T. Scholz, Species of Sciadicleithrum (Dactylogyridae: Ancyrocephalinae) of cichlid fishes from Southeastern Mexico and Guatemala: new morphological data and host and geographical records, Comp. Parasitol. 67 (2000) 85–91.

[9]

V.M. Vidal-Martínez, T. Scholz, L. Aguirre-Macedo, Dactylogyridae of cichlid fishes from Nicaragua, Central America, with descriptions of Gussevia herotilapiae sp. n. and three new species of Sciadicleithrum (Monogenea: Ancyrocephalinae), Comp. Parasitol. 68 (2001) 76–86.

[10]

E.F. Mendoza-Franco, P. Posel, S. Dumailo, Monogeneans (Dactylogyridae: Ancyrocephalinae) of freshwater fishes from the Caribbean coast of Nicaragua,

AC

CE

PT

ED

M

AN

US

CR

IP

T

[1]

17

ACCEPTED MANUSCRIPT Comp. Parasitol. 70 (2003) 32–41. doi: 10.1654/15252647(2003)070[0032:MDAOFF]2.0.CO;2. G. Malmberg, G. On the occurrence of Gyrodactylus on Swedish fishes, Skr. Södr. Sver. Fisk. För. Arsskr. 1956 (1957) 19–76 (In Swedish).

[12]

R. Ergens, The suitability of ammonium picrate-glycerin in preparing slides of lower Monogenoidea, Folia Parasit. 16 (1969) 320.

[13]

J.D. Mizelle, New species of trematodes from the gills of Illinois fishes, Am. Midl. Nat. 17 (1936) 785–806.

[14]

D.C. Kritsky, W.A. Boeger, E.T. Vernon, Neotropical Monogenea. 7. Parasites of the pirarucu, Arapaima gigas (Cuvier) with description of two new species and redescription of Dawestrema cycloancistrium Price & Nowlin, 1967 (Dactylogyridae: Ancyrocephalinae), P. Biol. Soc. Wash. 98 (1985) 321–331.

[15]

J.J. Astrin, X. Zhou, B. Misof, The importance of biobanking in molecular taxonomy, with proposed definitions for vouchers in a molecular context, Zookeys 635 (2013) 67–70. doi: 10.3897/zookeys.365.5875.

[16]

C.A. Mendoza-Palmero, I. Blasco-Costa, T. Scholz, Molecular phylogeny of Neotropical monogeneans (Platyhelminthes: Monogenea) from catfishes (Siluriformes), Parasit. Vectors. 8 (2015) 164. doi: 10.1186/s13071-015-0767-8.

[17]

J.J. Schmitter-Soto, A systematic revision of the genus Archocentrus (Perciformes: Cichlidae), with the description of two new genera and six new species, Zootaxa 1603 (2007) 1–76.

[18]

A.E. Lockyer, P.D. Olson, D.T.J. Littlewood, Utility of complete large and small subunit rRNA genes resolving the phylogeny of the Neodermata (Platyhelminthes): implications and a review of the cercomer theory, Biol. J. Linn. Soc. 78 (2003) 155– 171.

[19]

E.C. Werle, C. Schneider, M. Renner, M. Völker, W. Fiehn, (1994). Convenient single-step, one tube purification of PCR products for direct sequencing, Nucleic Acids Res. 22 (1994) 4354–4355.

[20]

D.T.J. Littlewood, M. Curini-Galletti, E.A. Herniou, The interrelationships of Proseriata (Platyhelminthes: Seriata) tested with molecules and morphology, Mol. Phylogenet. Evol. 16 (2000) 449–466. doi: 10.1006/mpev.2000.0802.

[21]

I. Sela, H. Ashkenazy, K. Katoh, T. Pupko, GUIDANCE2: accurate detection of unreliable alignment regions accounting for the uncertainty of multiple parameters, Nucleic Acids Res. 43 (2015) W7–W14. doi: 10.1093/nar/gkv318.

AC

CE

PT

ED

M

AN

US

CR

IP

T

[11]

18

ACCEPTED MANUSCRIPT O. Penn, E. Privman, G. Landan, D. Graur, T. Pupko, An alignment confidence score capturing robustness to guide tree uncertainty, Mol. Biol. Evol. 27 (2010) 1759–1767. doi: 10.1093/molbev/msq066.

[23]

S. Guindon, O. Gascuel, A simple, fast and accurate method to estimate large phylogenies by maximum-likelihood, Syst. Biol. 52 (2003) 696–704. doi: 10.1080/10635150390235520.

[24]

D. Darriba, G.L. Taboada, R. Doallo, D. Posada, jModelTest 2: more models, new heuristics and parallel computing, Nat. Methods. 9 (2012) 772. doi: 10.1038/nmeth.2109.

[25]

A. Stamatakis, RAxML-VI-HPC: maximum likelihood-based phylogenetic analyses with thousands of taxa and mixed models, Bioinformatics, 22 (2006) 2688–2690. doi: 10.1093/bioinformatics/btl446.

[26]

A. Stamatakis, P. Hoover, P. J. Rougemont, A rapid bootstrap algorithm for the RAxML Web Servers, Syst. Biol. 57 (2008) 758–771. doi: 10.1080/10635150802429642.

[27]

F. Ronquist, M. Teslenko, P. van der Mark, D.L. Ayres, A. Darling, S. Höhna, B. Larget, L. Liu, M.A. Suchard, J.P. Huelsenbeck, MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space, Syst. Biol. 61 (2012) 539–542. doi: 10.1093/sysbio/sys029.

[28]

J.P. Huelsenbeck, F. Ronquist, R. Nielsen, J.P. Bollback, Bayesian inference of phylogeny and its impact on evolutionary biology, Science, 294 (2001) 2310–2314. doi: 10.1126/science.1065889.

[29]

M.A. Miller, W. Pfeiffer, T. Schwartz, Creating the CIPRES science gateway for inference of large phylogenetic trees. in: SC10 Workshop on Gateway Computing Environments (GCE10). New Orleans, 14 November 2010. pp. 1–8.

[30]

K. Tamura, D. Peterson, N. Peterson, G. Stecher, M. Nei, S. Kumar, MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods, Mol. Biol. Evol. 28 (2001) 2731–2379. doi: 10.1093/molbev/msr121.

[31]

D.C. Kritsky, V.M. Vidal-Martínez, R. Rodríguez-Canul, Neotropical Monogenoidea. 19. Dactylogyridae of cichlids (Perciformes) from the Yucatan Peninsula, with descriptions of three new species of Sciadicleithrum Kritsky, Thatcher and Boeger, 1989, J. Helminth. Soc. Wash. 61 (1994) 26–33.

[32]

E.F. Mendoza-Franco, T. Scholz, V.M. Vidal-Martínez, Sciadicleithrum meekii sp. n. (Monogenea: Ancyrocephalinae) from the gills of Cichlasoma meeki (Pisces: Cichlidae) from cenotes (= sinkholes) of the Yucatan Peninsula, Mexico, Folia Parasit. 44 (1997) 205–208.

AC

CE

PT

ED

M

AN

US

CR

IP

T

[22]

19

ACCEPTED MANUSCRIPT

S. Bellay, R.M. Takemoto, F.H. Yamada, G.C. Pavanelli, Two new species of Sciadicleithrum (Monogenea: Dactylogyridae), gill parasites of Geophagus proximus (Castelnau) (Teleostei: Cichlidae), from the upper Paraná River floodplain, Brazil, Zootaxa 2081 (2009) 67–66.

[34]

E.F. Mendoza-Franco, J.M. Caspeta-Mandujano, G. Salgado-Maldonado, New species of Cacatuocotyle (Monogenoidea, Dactylogyridae) parasitizing the anus and the gill lamellae of Astyanax aeneus (Pisces, Ostariophysi: Characidae) from the Rio Lacantún basin in the Biosphere Reserve of Montes Azules, Chiapas, Mexico, Parasitol. Res. 112 (2013) 199–205. doi: 10.1007/s00436-012-3126-0.

[35]

W.A. Boeger, M.V. Domingues, D.C. Kritsky, Neotropical Monogenoidea. 32. Cacatuocotyle paranaensis n. g., n. sp. (Dactylogyridae, Ancyrocephalinae) from Characidium spp. (Teleostei, Characidae) from the State of Paraná, Brazil, Syst. Parasitol. 36 (1997) 75–78.

[36]

V.E. Thatcher, Amazon fish parasites, second ed., Pensoft, Sofia, 2006.

[37]

G. Salgado-Maldonado, J.M. Caspeta-Mandujano, F. Moravec, E. Soto-Galera, R. Rodiles-Hernández, G. Cabañas-Carranza, J. Montoya-Mendoza, Helminth parasites of freshwater fish in Chiapas, Mexico, Parasitol. Res. 108 (2011) 31–59. doi: 10.1007/s00436-010-2035-3.

[38]

L. Plaisance, D.T.J. Littlewood, P.D. Olson, S. Morand, Molecular phylogeny of gill monogeneans (Platyhelminthes, Monogenea, Dactylogyridae) and colonization of Indo-West Pacific butterflyfish hosts (Perciformes, Chaetodontidae), Zool. Scr. 34 (2005) 425–436. doi: 10.1111/j.1463-6409.2005.00191.x.

[39]

L. Pouyaud, E. Desmarais, M. Deveney, A. Pariselle, Phylogenetic relationships among monogenean gill parasites (Dactylogyridea, Ancyrocephalidae) infesting tilapiine hosts (Cichlidae): systematic and evolutionary implications, Mol. Phylogenet. Evol. 38 (2006) 241–249. doi: 10.1016/j.ympev.2005.08.013.

[40]

X.Y. Wu, X.Q. Zhu, M.Q. Xie, A.X. Li, 2007. The evaluation for generic-level monophyly of Ancyrocephalinae (Monogenea, Dactylogyridae) using ribosomal DNA sequence data, Mol. Phylogenet. Evol. 44 (2007) 530–544. doi: 10.1016/j.ympev.2007.03.025.

AC

CE

PT

ED

M

AN

US

CR

IP

T

[33]

[41] M. Mendlová, A. Pariselle, M. Vyskočilová, A. Šimková, Molecular phylogeny of monogeneans parasitising African freshwater Cichlidae inferred from LSU rDNA sequences, Parasitol. Res. 107 (2010) 1405–1413. doi: 10.1007/s00436-010-2008-6. [42]

M. Mendlová, Y. Desdevises, K. Civáňová, A. Pariselle, A. Šimková, Monogeneans of west African cichlid fish: evolution and cophylogenetic interactions, PlosOne 7 (2012) e37268. doi: 10.1371/journal.pone.0037268.

20

ACCEPTED MANUSCRIPT I. Přikrylová, M.P.M. Vanhove, S.B. Janssens, P.A. Billeter, T. Huyse, Tiny worms from a mighty continent: High diversity and new phylogenetic lineages of African monogeneans, Mol. Phylogenet. Evol. 67 (2013) 43–52. doi: 10.1016/j.ympev.2012.12.017.

[44]

E.F. Mendoza-Franco, V.M. Vidal-Martínez, Phylogeny of species of Sciadicleithrum (Monogenoidea: Ancyrocephalinae), and their historical biogeography in the Neotropics, J. Parasitol. 91 (2005) 253–259. doi: 10.1645/GE3389.

[45]

A. Choudhury, M. García-Varela, G. Pérez-Ponce de León, Parasites of freshwater fishes and the Great American Biotic Interchange: a bridge too far?, J. Helminthol. (2016) doi: 10.1017/S0022149X16000407.

[46]

A. Pariselle, W.A. Boeger, J. Snoeks, C.F. Bilong, S. Morand, M.P.M. Vanhove, The monogenean parasite fauna of cichlids: A potential tool for host biogeography. Int. J. Evol. Biol. (2011) 1–15. doi: 10.4061/2011/471480.

[47]

G. Pérez-Ponce de León, A. Choudhury, Biogeography of helminth parasites of freshwater fish in México: the search for patterns and processes, J. Biogeogr. 32 (2005) 645–659. doi: 10.1111/j.1365-2699.2005.01218.x.

[48]

M. Friedman, B.P. Keck, A. Dornburg, R.I. Eytan, C.H. Martin, C.D. Hulsey, P.C. Wainwright, T.J. Near, Molecular and fossil evidence place the origin of cichlid fishes long after Gondwanan rifting, Proc. R. Soc. B. 280 (2013) 20131733. doi: 10.1098/rspb.2013.1733.

[49]

A. Šimková, I. Matějosová, C.O. Cunningham, A molecular phylogeny of the Dactylogyridae sensu Kritsky & Boeger (1989) based on the D1–D3 domains of large subunit rDNA, Parasitology. 133 (2006) 43–53. doi: 10.1017/S0031182006009942.

[50]

E.F. Mendoza-Franco, C.A. Mendoza-Palmero, T. Scholz, New species of Ameloblastella Kritsky, Mendoza-Franco & Scholz, 2000 and Cosmetocleithrum Kritsky, Thatcher & Boeger, 1986 (Monogenea: Dactylogyridae) infecting the gills of catfishes (Siluriformes) from the Peruvian Amazonia, Syst. Parasitol. 93 (2016) 847–862. doi: 10.1007/s11230-016-9671-7.

[51]

X.Y. Wu, X.Q. Zhu, M.Q. Xie, A.X. Li, The radiation of Haliotrema (Monogenea: Dactylogyridae: Ancyrocephalinae): molecular evidence and explanation inferred from LSU rDNA sequences, Parasitology. 132 (2006) 659–668. doi: 10.1017/S003118200500956X.

[52]

J. Berhrmann-Godel, S. Roch, A. Brinker, Gill worm Ancyrocephalus percae (Ergens 1966) outbreak negative impacts the Eurasian perch Perca fluviatilis L. stock of Lake Constance, Germany, J. Fish. Dis. 37 (2013) 925–930. doi: 10.1111/jfd.12178.

AC

CE

PT

ED

M

AN

US

CR

IP

T

[43]

21

ACCEPTED MANUSCRIPT

X.Y. Wu, X.Q. Zhu, M.Q. Xie, J.Q. Wang, A.X. Li, The radiation of Thaparocleidus (Monogenoidea: Dactylogyridae: Ancylodiscoidinae): phylogenetic analyses and taxonomic implications inferred from ribosomal DNA sequences, Parasitol. Res. 102 (2008) 283–288. doi: 10.1007/s00436-007-0760-z.

[54]

I. Blasco-Costa, R. Míguez-Lozano, V. Sarabeev, J.A. Balbuena, Molecular phylogeny of species of Ligophorus (Monogenea: Dactylogyridae) and their affinities within the Dactylogyridae, Parasitol. Int. 61 (2012) 619–627. doi: 10.1016/j.parint.2012.06.004.

[55]

B.T. Dang, A. Levsen, A. Schander, G.A. Bristow, Some Haliotrema (Monogenea: Dactylogyridae) from cultured grouper (Epinephelus spp.) with emphasis on the phylogenetic position of Haliotrema cromileptis, J. Parasitol. 96 (2010) 30–39. doi: 10.1645/GE-2140.1.

[56]

X-J. Ding, X-H. Liao, Phylogenetic position of the monogeneans Pseudodactylogyrus, Heteronchocleidus and Trianchoratus inferred from the 5’ terminal sequences of 28S rDNA, Acta Zoot. Sinica. 30 (2005) 244–251 (In Chinese).

[57]

P.D. Olson, D.T.J. Littlewood, Phylogenetics of the Monogenea – evidence from a medley of molecules, Int. J. Parasitol. 32 (2002) 233–244.

[58]

I. Mollaret, G.M.B. Jamieson, R.D. Adlard, A. Hugall, G. Lecointre, C. Chombard, J.L. Justine, Phylogenetic analysis of the Monogenea and their relationships with Digenea and Eucestoda inferred from 28S rDNA sequences, Mol. Biochem. Parasit. 90 (1997) 433–438.

[59]

L.A. Chisholm, J.A.T. Morgan, R.D. Adlard, I.D. Whittington, Phylogentic analysis of the Monocotylidae (Monogenea) inferred from 28S rDNA sequences, Int. J. Parasitol. 31 (2001) 1537–1547.

AC

CE

PT

ED

M

AN

US

CR

IP

T

[53]

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ACCEPTED MANUSCRIPT Legend figures

Fig. 1. Parasciadicleithrum octofasciatum n. sp. from the gills of Rocio octofasciata. (A) Whole specimen (composite, ventral view); (B) Ventral anchor; (C) Dorsal anchor. (D) Ventral bar. (E) Dorsal bar. (F) Copulatory complex (ventral view). (G) Hook pair 1. Scale

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bars: A = 100 µm, B-F = 20 µm, G = 10 µm.

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Fig. 2. Morphological comparison of gonads’ dimension (germaria and testes) between

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Parasciadicleithrum octofasciatum n. sp. and four species of Sciadicleithrum. (A) Parasciadicleithrum octofasciatum n. sp. (paratype CNHE 10024). (B) Sciadicleithrum

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bravohollisae from Paraneetroplus fenestratus (Veracruz, Mexico, voucher CNHE 6057). (C) S. meekii from Thorichthys meeki (Chiapas, Mexico, voucher CNHE 10032). (D) S.

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mexicanum from Cichlasoma urophthalmus (Tabasco, Mexico, voucher CNHE 10031). (E) S. splendidae from Parachromis friedrichsthalii (Campeche, Mexico, voucher CNHE

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10033). Arrows indicate the position of germarium. Brackets indicate the position of testis.

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All micrographs were taken at 100X magnification. Scale bars: A–E = 20 µm.

Fig. 3. Phase contrast microphotographs of haptoral bars comparing their morphology. (A)

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Parasciadicleithrum octofasciatum n. sp. (paratype CNHE 10024). (B) Sciadicleithrum bravohollisae from Vieja bifasciata (Campeche, Mexico, specimen not deposited in the

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CNHE). (C) S. meekii from Thorichthys meeki (Campeche, Mexico, voucher CNHE 10032). (D) S. mexicanum from Petenia splendidae (Tabasco, Mexico; CNHE 10031). (E)

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S. splendidae from Parachromis friedrichsthalii (Campeche, Mexico, voucher CNHE 10033). All micrographs were taken at 100X magnification. Scale bars: A–E = 50 µm.

Fig. 4. Molecular phylogeny of the Dactylogyridae estimated by Maximum Likelihood using partial sequences of the 28S rRNA gene (stringent alignment, 535 bp-long) showing the placement of Parasciadicleithrum octofasciatum n. sp., newly sequenced for this study. Species belonging to Monocotylidae, Tetraonchidae, Pseudomurraytrematidae and Diplectanidae were used as outgroups. GenBank sequence ID follows species name and labels on the clades follow Mendoza-Palmero et al. [16]. Posterior probabilities and

23

ACCEPTED MANUSCRIPT Maximum Likelihood support values are given above the branches (posterior probabilities <0.90 and bootstrap values <60 not reported).

Fig. 5. Haptoral armament and copulatory complex of Sciadicleithrum maculicaudae (holotype; CNHE 4164). (A) Ventral bar. (B) Dorsal bar. (C) Ventral anchor. (D) Dorsal

AC

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PT

ED

M

AN

US

CR

IP

T

anchor. (E) Copulatory organ. Scale bars: A–E = 20 µm.

24

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M

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IP

T

ACCEPTED MANUSCRIPT

Figure 1 25

US

CR

IP

T

ACCEPTED MANUSCRIPT

AC

CE

PT

ED

M

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Figure 2

26

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IP

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ACCEPTED MANUSCRIPT

Figure 3

27

AC

Figure 4

CE

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ED

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IP

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ACCEPTED MANUSCRIPT

28

M

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ACCEPTED MANUSCRIPT

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Figure 5

29

ACCEPTED MANUSCRIPT Table 1. Species of monogenoids, hosts, geographical distribution and GenBank accession numbers used in this study. Parasite species Host Host family Locality No. GenBank Reference isolate ID s Dactylogyridae

Aliatrema cribbi

Chaetodon citrinellus Rhamdia quelen

Chaetodontida e Heptapteridae

Ameloblastella edentensis

Hypophthalmus edentatus

Pimelodidae

Ancyrocephalus mogurndae

Siniperca chuatsi

Percichthyidae

Ancyrocephalus paradoxus

Sander lucioperca

Percidae

Chauhanellus boegeri

AY820612 [38]

1

KP056251 [16]

River Morava, Czech Republic

1

AJ969952

Lake Constance, Germany

1

KF499080 [52]

Santa Clara, Iquitos, Peru

1

KP056239 [16]

Goeldiella eques Heptapteridae

Río Nanay, Iquitos, Peru

1

KP056238 [16]

Pomadasys maculatus Tachysurus fulvidraco

Haemulidae

1

DQ537364 [40]

1

EF100541

Genidens genidens

Ariidae

Guangdong , China Shaoguan, Guangdong , China Baia de Antonina, municipalit y of Antonina, Paraná, Brazil

1

KP056241 [16]

M

AN

US

DQ157667 [51]

Percidae

PT

Bychowskyella pseudobagri

1

1

CE

AC

Bravohollisia rosetta

[49]

Fuzhou, Fujian Province, China

Goeldiella eques Heptapteridae

Aphanoblastella sp. 3

AJ969951

KP056255 [16,50]

Ancyrocephalus percae Perca fluviatilis

Aphanoblastella aurorae

1

1

ED

Ameloblastella chavarriai

River Dunaj, Slovak Republic French Polynesia Lago de Catemaco, Veracruz, Mexico Río Nanay, Iquitos, Peru

T

Centrarchidae

IP

Lepomis gibbosus

CR

Actinocleidus recurvatus

Bagridae

30

[48]

[53]

ACCEPTED MANUSCRIPT

Cichlidogyrus sclerosus

Oreochromis niloticus

Cichlidae

Cichlidogyrus tilapiae

Hemichromis fasciatus

Cichlidae

Cosmetocleithrum bifurcum

Hassar orestis

Doradidae

Dactylogyrus nanus

Rutilus rutilus

Cyprinidae

Dactylogyrus petruschewskyi

Megalobrama amblycephala

Cyprinidae

Demidospermus mortenthaleri

Brachyplatystom Pimelodidae a juruense

Baia de Antonina, municipalit y of Antonina, Paraná, Brazil Panyu, Guangdong Province, China Senegal, Africa Aquarium Río Momón, Iquitos, Peru

1

KP056242 [16]

1

DQ157660 [51]

1

HQ010029 [41]

T

Ariidae

IP

Genidens genidens

1

KP056216 [16,50]

M

ED

PT

Demidospermus sp. 11 Brachyplatystom Pimelodidae a vaillantii

CE

River Morava, Czech Republic China

1

AJ969942

1

Santa Clara, Iquitos, Peru

1

AY548927 Ding and Liao (unpublished ) KP056245 [16]

Río Nanay, Iquitos, Peru

1

KP056235 [16]

Río Nanay, Iquitos, Peru Ebro Delta, Spain Bay Cerritos, Mazatlan, Mexico

1

KP056236 [16]

1

JN996800

1

AN

Table 1. cont.

US

CR

Chauhanellus sp.

Demidospermus sp. 23 Brachyplatystom Pimelodidae a vaillantii

[49]

Liza ramada

Mugilidae

Euryhaliotrema perezponcei

Lutjanus guttatus

Lutjanidae

Euryhaliotrematoides pirulum

Chaetodon lunula

Chaetodontida e

French Polynesia

1

HQ615996 SolerJiménez et al. (unpublished ) AY820618 [39]

Serranidae

Nha Trang Bay, Vietnam

1

EU523146 [55]

AC

Ergenstrema mugilis

Haliotrema cromileptis Epinephelus coioides, E. bleekeri

31

[54]

ACCEPTED MANUSCRIPT Weihai, Shangdong Province, China Bay Cerritos, Mazatlan, Mexico

1

DQ157662 [51]

Haliotrematoides guttati

Lutjanus guttatus

Lutjanidae

1

Lutjanidae

Pacific Coast, Mexico

1

Ameiurus nebulosus

Ictaluridae

Ligophorus vanbenedenii

Liza aurata

Mugilidae

River Vltava, Czech Republic Ebro Delta, Spain

HQ615993 SolerJiménez et al. (unpublished ) KC663679 GarcíaVázquéz et al. (unpublished ) AJ969939 [49]

Haliotrematoides spinatus

Lutjanus guttatus

Ligictaluridus pricei

Metahaliotrema mizellei

Scatophagus argus

Scatophagidae

Onchocleidus similis

Lepomis gibbosus

Centrarchidae

Onchocleidus sp.

Lepomis macrochirus

Centrarchidae

Rocio octofasciata

Cichlidae

AC

Protogyrodactylus alienus

Gerres filamentosus

JN996802

Panyu, Guangdong Province, China River Dunaj, Slovak Republic Guangzhou , China

1

DQ157647 [51]

1

AJ969938

1

AY841873 [56]

Unnamed creek in Ejido Reforma Agraria, Chiapas, Mexico Dayawan, Guangdong Privince, China Yangjiang, Guangdong Province, China River Dunaj, Slovak Republic

6

KY305880 Present -85 study

1

DQ157650 [51]

1

DQ157653 [51]

1

AJ969950

[49]

Neusiedler Lake,

1

AJ969949

[49]

US

Gerreidae

Protogyrodactylus hainanensis

Therapon jarbua Terapontidae

Pseudodactylogyrus anguillae

Anguilla anguilla

Anguillidae

Pseudodactylogyrus bini

Anguilla anguilla

Anguillidae

32

1

1

AN

M

ED

CE

Parasciadicleithrum octofasciatum n. sp.

PT

Table 1. cont.

T

Platycephalida e

IP

Platycephalus indicus

CR

Haliotrema platycephali

[54]

[49]

ACCEPTED MANUSCRIPT Austria

Clarias batracus Clariidae Pareutropius debauwi

Schilbeidae

Sciadicleithrum bravohollisae

Paraneetroplus fenestratus

Cichlidae

Sciadicleithrum meekii

Thorichthys meeki

Cichlidae

Sciadicleithrum mexicanum

Rocio octofasciata

Cichlidae

Sciadicleithrum splendidae

Parachromis friedrichsthalii

AF382058 [57]

Guangzhou , China Aquarium from the Czech Republic, origin West Africa Lago de Catemaco, Veracruz, Mexico Unnamed creek in Ejido Reforma Agraria, Chiapas, Mexico Unnamed creek in Ejido Reforma Agraria, Chiapas, Mexico Laguna El Vapor, Campeche, Mexico Panyu, Guangdong Province, China Heron Island, Queensland , Australia Guangzhou , China

1

AY841874 [56]

1

KP056244 [16]

AN

M ED

PT

1

T

Quadriacanthus kobiensis Schilbetrema sp.

Green Island, Australia

IP

Siganidae

2

CR

Siganus doliatus

Cichlidae

KY305878 Present -79 study

2

KY305888 Present -89 study

2

KY305886 Present -87 study

2

KY305890 Present -91 study

1

DQ157659 [51]

1

AF026114 [58]

1

AY841872 [56]

US

Pseudohaliotrema sphincteroporus

Cichlidae

Tetrancistrum sp.

Siganus fuscescens

Siganidae

Pangasianodon hypophthalmus

Pangasidae

Thaparocleidus asoti

Silurus asotus

Pangasidae

Chongqing City, China

1

DQ157669 [51]

Thaparocleidus siluri

Silurus glanis

Siluridae

River Morava, Czech

1

AJ969940

AC

CE

Scutogyrus longicornis Oreochromis niloticus

Thaparocleidus campylopterocirrus Table 1. cont.

33

[49]

ACCEPTED MANUSCRIPT Republic Aguarunichthys torosus

Vancleaveus janauacaensis

Pterodoras granulosus

Dactylogyridae gen. sp. 4

Ageneiosus vittatus

Dactylogyridae gen. sp. 9

Platynematichth ys notatus

Pimelodidae

Santa Clara, Iquitos, Peru

Dactylogyridae gen. sp. 10

Platynematichth ys notatus

Pimelodidae

Santa Clara, Iquitos, Peru

1

KP056225 [16]

Dactylogyridae gen. sp. 13

Hypophthalmus edentatus

Pimelodidae

Río Nanay, Iquitos, Peru

1

KP056230 [16]

Dactylogyridae gen. sp. 18

Pseudoplatystom Pimelodidae a fasciatum

Santa Clara, Iquitos, Peru

1

KP056231 [16]

Dactylogyridae gen. sp. 26

Platynematichth ys notatus

Pimelodidae

Santa Clara, Iquitos, Peru

1

KP056234 [16]

Nibea albiflora

Sciaenidae

Panyu, Guangdong Province, China

1

DQ157672 [51]

Pseudorhabdosynochu s epinepheli*

Epinephelus bruneus

Serranidae

Huidong, Guangdong Province, China

1

AY553622 [51]

Pseudorhabdosynochu s lantauensis*

Epinephelus bruneus

Serranidae

Huidong, Guangdong Province, China

1

AY553624 [51]

Sinodiplectanotrema argyromus*

Pennahia anea, Nibea albiflora

Sciaenidae

Panyu, Guangdong

1

DQ157673 [51]

AC

Murraytrema pricei*

US

AN

M

ED

34

1

KP056219 [16]

1

KP056247 [16]

1

KP056218 [16]

IP 1

CR

Santa Clara, Iquitos, Peru Doradidae Río Itaya, Iquitos, Peru Auchenipterida Río Nanay, e Iquitos, Peru

PT CE

Diplectanidae

Pimelodidae

T

Unibarra paranoplatensis

KP056222 [16]

ACCEPTED MANUSCRIPT Province, China Table 1. cont. Monocotylidae Myliobatidae

Heron Island, Australia

1

AF348350 [59]

Decacotyle lymmae*

Aetobatus narinari

Myliobatidae

Heron Island, Australia

1

AF348359 [59]

Dendromonocotyle octodiscus*

Dasyatis americana

Dasyatidae

Gulf of Mexico, Mexico

Catostomus ardens

Catostomidae

Exos lucius

Escocidae

Tetraonchidae

ED

Tetraonchus monenteron*

M

IP

Snake River, Idaho, USA

1

AF382059 [57]

River Morava, Czech Republic

1

AJ969953

CR

AF348352 [59]

US

Pseudomurraytrema sp.*

1

AN

Pseudomurraytrematid ae

T

Clemacotyle australis* Aetobatus narinari

AC

CE

PT

Sequences in bold are newly obtained in this study. * Species used as outgroups.

35

[49]

ACCEPTED MANUSCRIPT

n = 46

n = 24

n = 13

n=5

n=2

n=2

Bl

214 (146– 275; n = 21)

243 (67– 363; n = 14)

233 (192– 265; n = 5)

294 (269– 320; n = 4)

250 (n = 1)

538 (332– 745; n = 2)

391 (296– 558; n = 8)

516 (425– 628; n = 9)

83 (74– 98 (78–118; 92, n = 2) n = 2)

103 (80– 121; n = 9)

119 (101– 141; n = 10)

25 (18–30; n = 2)

22 (20–25; n = 7)

27 (23–30; n = 10)

–

–

–

–

38 (27–53; n = 7) 19 (16–23; n = 7)

59 (43–75; n = 10) 34 (20–47; n = 10)

47 (n = 1)

59 (n = 1)

45 (36–57; n = 5)

55 (38–73; n = 8)

22 (n = 1)

39

27 (23–30; n = 5)

24 (19–30, n = 8)

77 (n = 1)

–

72 (57–89; n = 9)

56 (52–64; n = 9)

20 (n = 1)

15 (12–18; n = 17)

MC Or

10 (8–12; n = 10)

Nr

1.5

Val

26 (23–29; n = 20)

Vab w

33 (33– 34; n = 2)

AC

MC Ol

CE

PT

ED

M

AN

14 (12–17; n = 20)

22 (21– 54 (43–62; 23, n = 3) n = 9)

CR

49 (33–65; n = 24)

n = 18

US

72 (15– 61 (50– 69 (58–85; 130; n = 75, n = 3) n = 4) 15) 14 (11– 15 (12–19; 61 (50– 17 (16–19; Phw 16; n = n = 24) 75, n = 3) n = 2) 11) 30 (22–40; 29 (25–33, Gl – – n = 13) n = 2) 11 (10–19; 20 (12–29; Gw – – n = 14) n = 2) 29 (21– 18 (13–25; Tl 35; n = – 40 (n = 2) n = 3) 3) 14 (8– 10 (8–11; n 22–25 (n Tw 18; n = – = 3) =2) 3) 79 (58– 83 (65– 41 (35–48; Hl 101; n = 107; n = – n = 22) 12) 6) 72 (56– 57 (47–72; 45 (35– 34 (26–39; Hw 96; n = n = 21) 62, n = 6) n = 3) 12) Bw

n = 16

IP

Code

T

Table 2. Comparative measurements of Parasciadicleithrum octofasciatum n. sp. and selected species of Sciadicleithrum from the Neotropical region. P. S. S. S. S. S. S. S. octofasciat frequens nicaraguen splendida maculicaud bravohollis bravohollisa meekii* um n. sp. * se* e* ae* ae* e† Geophag Paraneetrop Rocio Paraneetrop us Thorichth Amphiloph Petenia lus Cichlasoma octofasciat lus brasilens ys meekii us alfari splendida maculicaud pearsei a fenestratus is a Campech Chiapas, Paraná, Yucatán, Campeche, Veracruz, Nicaragua e, Nicaragua Mexico Brazil Mexico Mexico Mexico Mexico

62 (n = 1)

98 (75–122; 97 (83–111; 93 (85–101; n = 2) n = 8) n = 9)

230 (228– 233; n = 2)

42 (41–43; n = 2)

54 (45–60; n = 7)

45 (43–48; n = 5)

10 (10– 11; n = 2) 1.5 19 (18– 21; n = 6)

–

–

31 (27– 35; n = 2)

–

–

–

3 23 (21– 25; n = 19)

1

2.5

–

–

–

34 (26–39; 29 (29–30; n 32 (n = 1) n = 18) = 4)

36 (34–39; n = 6)

31 (30–33, n = 6)

15 (15– 16; n = 5)

13 (12– 15; n = 20)

16 (12–18, 14 (12–18; n 17 (n = 1) n = 18) = 4)

22 (21–24; n = 6)

21 (19–23; n = 6)

36

ACCEPTED MANUSCRIPT 44 (42– 40 (36– 43 (40–46, 33 (32–35; n 41 (39–44; 33 (32–34, n 48; n = 43, n = 40 (n = 1) n = 17) = 4) n = 7) = 6) 10) 17) 29 (26– 13 (12– Dab 11 (10–17; 12 (8–15; n 15 (10–18; n 17 (14–18; 18 (17–19; n 31; n = 14; n = 14 (n = 1) w n = 20) = 16) = 4) n = 7) = 6) 7) 10) 28 (20– 33 (30– 26 (23–30; 29 (26–32; 39 (38– 34 (34–35, n 31 (28–34; 34 (30–36; n Vbl 33; n = 34, n = n = 21) n = 8) 40; n = 2) = 2) n = 5) = 6) 9) 10) 33 (32– 32 (30– 23 (20–26; 26 (24–30, 37–38 (n 31 (30–33; n 32 (30–33; 35 (33–37; n Dbl 35; n = 37, n = n = 20) n = 8) = 2) = 2) n = 6) = 6) 4) 12) 14 (12– 13 (11– 12 (10–15; 14 (12–15, 15–16 (n 15 (15–16; n 16 (14–17; 15 (14–16; n Hkl 16; n = 14, n = n = 44) n = 29) = 2) = 3) n = 27) = 6) 11) 20) * Measurements taken from original descriptions. † Measurements taken from voucher specimens (CNHE 6057–8, 6065–6, 7109–11, 7114). Codes: Bl = Body length, Bw = Body width, Phw = Pharynx width, Gl = Germarium length, Gw = Germarium width, Tl = Testis length, Tw = Testis width, Hl = Haptor length, Hw = Haptor width, MCOl = Male Copulatory Organ length, MCOr = Male Copulatory Organ fist ring diameter, Nr = Number of rings, Apl = Accessory piece length, Val = Ventral anchor length, Vaw = Ventral anchor width, Dal = Dorsal anchor length, Daw = Dorsal anchor base width, Vbl = Ventral bar length, Dbl = Dorsal bar length, Hkl = Hook length.

CE

PT

ED

M

AN

US

CR

IP

T

26 (23–30; n = 20)

AC

Dal

37

ED

M

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CR

IP

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ACCEPTED MANUSCRIPT

AC

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Graphical abstract

38

ACCEPTED MANUSCRIPT Highlights 

Parasciadicleithrum octofasciatum n. gen., n. sp. is described by using an integrative taxonomic approach.



The new genus is morphologically similar to Sciadicleithrum but genetically distant.



The monotypic Parasciadicleithrum n. gen. can be confidentially distinguished

IP



T

from Sciadicleithrum spp. based on the basis of molecular data.

Parasciadicleithrum octofasciatum n. gen., n. sp. is closely related to dactylogyrids

Phylogeny of dactylogyrids infecting Neotropical cichlids reveals a complex

CE

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evolutionary history of these parasites.

AC



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from African freshwater cichlids.

39