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Studies on infestation and effects of certain parasites of Mystus gulio along the south-east coast of India
Studies on infestation and effects of certain parasites of My&us gulio along the south-east coast of India
P. NATARAJAN’
and S. FELIX
College of Fisheries, Tamil Nadu Agricultural University, Tuticorin 628 008 (India) ‘Present address: Department of Aquatic Biology and Fisheries, University of Kerala, Trivandrum 695 007 (India) (Accepted 22 January 1987 ) In India, studies on parasites and diseases of fishes are largely concerned with systematics. Except for a few reports during the 1960’s on diseases of cultured fishes and some current sporadic reports, knowledge on diseases of Indian fishes is lamentably meagre. The present study deals with the infestation and effects of parasites of Mystus gulio, a species of commercial value in India. In total 193 fishes collected for a period of one year, from January-December 1984, were examined for evidence of parasites. The prevalence and mean intensity in relation to multiple infestation were 88.1% and 89.5% respectively. Prevalence owing to individual parasites was greatest in the case of Neomurraytrema tengra (80.8% ) followed by Philometra sp. (32.2% ) , Acanthosentis antespinus (28% ) and Ergasilus sp. (23.8%). A significant inverse relationship of prevalence and mean intensity with regard to sex was noticed. The prevalence in relation to length groups showed that in both sexes it was minimum in the highest length groups. The changes in haematolo~cal parameters owing to different levels of infestation are presented in Fig. 1. ~aematolo~cal parameters revealed a drastic reduction in the total erythrocyte count (RBC ) , total leucocyte count ( WBC ) , haemoglobin content (Hb) , erythrocyte sedimentation rate (ESR) and haematocrit (Ht) coupled with an elevation in the mean corpuscular volume (MCV) , mean corpuscuiar haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) in the infested fish when compared with the uninfested ones. A significant drop in the erythrocyte count was also noted (P < 0.01) . The percentage reduction was greatest in ESR (45.3%) followed by WBC (20.7%), RBC (10.4%), Hb (2.7%) and Ht (1.2%). The percentage composition of lymphocytes showed more leucocytes in infested fish and more granulocytes in uninfested ones. The changes in haematological values indicate that during the onset of infestation, the values of RBC, WBC, Hb, Ht showed a rise as compared with uninfested fish. Of these factors, WBC showed a steady rise, indicating the increase in the number of leucocytes during the initial stage of attck. The ESR values, however, showed a decreasing trend. Although a rise or drop in values could be observed at different levels, the ESR showed a positive slope while RBC, WBC, Hb and Ht showed negative slopes when infestation increased to over 800, indicating disease manifestation in fish. Such a trend in values was noticed by ~~krishnan et al. (1984) in ~iodo~ ~ystr~~infested by the cestode parasite ~mnorhynch~ gigas. The averge values of oxygen consumption, ammonia excretion, ammonia quotient and random activity of uninfested and infested fish are given in Table 1. As seen from the table, the values generally increased during the onset of infestation. In the case of multiple infestation, oxygen consumption showed a negative correlation with random activity while ammonia excretion and ammonia quotient followed a positive trend. However, in the case of Liza tade a negative trend was reported by Rajagopalaswamy (1985).
234
8.5 -
6.5 l-8
1.2
.
1.0
mu6
3
:I’ll: /
2 1.8
5
t
1.4
1
I
0
8
I-200
I
I
I
201-400 LO%630 601-800 > BOO
INF~CTIO~
LEVEL
Fig. 1. Haematological parameters in relation to different levels of infest&ion in My&us gulio. TABLE 1 Activity and metabolic rates in uninfested and infested Mystus gulio Levels of infestation
l-i00 101-200 201-300 301-400 401-500
Activity
Routine O2 consumption
Routine ammonia excretion
Routine a~onia quotient
25.350 -t 7.93
219.191 I!I26.74
13.588 k 1.77
0.0513 kO.014
56.260 I!Z10.20 35.639 rt: 9.91 2.313 + 0.43* 2.421 rt 0.86 4.oooi 1.16
301.997 r_+ 28.44 219.192 rir50.67 407.586 I!I64.12 370.292 rtr50.14 319.709 rt:40.66**
31.745 ?I 4.25** 27.385 rt 0.96 14.852 It 1.79 24.168 I: 2.21 33.6’I6 + Z&B**
0.1192rf:0.020 0.1880 + 0.780 0.0330 LO.003 0.0620 i 0.010 0.1092 f 0.010
**p
The authors are thank~l to Dr. G. Jagatheesan, Dean in charge, Fisheries College, Tuticorin, for his encouragement and-support.
REFERENCES Radhakrishnan, S., Nair, N.B. and Balasubramanian, N.K., 1984. Gymnorhynchus gigas Plerocercoid (Cestoda: Gymnorhynchidae) . Infection of the liver of Diodon hystrix (Pisces: Diodontidae)). Haematological changes in infected fish. Fisch und Umwelt, 13: 27-39. Rajagopalaswamy, C.B.T., 1985. Studies on parasites of mullet, Liza tade (Forskal) with special reference to host-parasite relationship. M.F.Sc. Thesis, TNAU, Coimbatore, India.
P. NATARAJAN’
and S. FELIX
College of Fisheries, Tamil Nadu Agricultural University, Tuticorin 628 008 (India) ‘Present address: Department of Aquatic Biology and Fisheries, University of Kerala, Trivandrum 695 007 (India) (Accepted 22 January 1987 ) In India, studies on parasites and diseases of fishes are largely concerned with systematics. Except for a few reports during the 1960’s on diseases of cultured fishes and some current sporadic reports, knowledge on diseases of Indian fishes is lamentably meagre. The present study deals with the infestation and effects of parasites of Mystus gulio, a species of commercial value in India. In total 193 fishes collected for a period of one year, from January-December 1984, were examined for evidence of parasites. The prevalence and mean intensity in relation to multiple infestation were 88.1% and 89.5% respectively. Prevalence owing to individual parasites was greatest in the case of Neomurraytrema tengra (80.8% ) followed by Philometra sp. (32.2% ) , Acanthosentis antespinus (28% ) and Ergasilus sp. (23.8%). A significant inverse relationship of prevalence and mean intensity with regard to sex was noticed. The prevalence in relation to length groups showed that in both sexes it was minimum in the highest length groups. The changes in haematolo~cal parameters owing to different levels of infestation are presented in Fig. 1. ~aematolo~cal parameters revealed a drastic reduction in the total erythrocyte count (RBC ) , total leucocyte count ( WBC ) , haemoglobin content (Hb) , erythrocyte sedimentation rate (ESR) and haematocrit (Ht) coupled with an elevation in the mean corpuscular volume (MCV) , mean corpuscuiar haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) in the infested fish when compared with the uninfested ones. A significant drop in the erythrocyte count was also noted (P < 0.01) . The percentage reduction was greatest in ESR (45.3%) followed by WBC (20.7%), RBC (10.4%), Hb (2.7%) and Ht (1.2%). The percentage composition of lymphocytes showed more leucocytes in infested fish and more granulocytes in uninfested ones. The changes in haematological values indicate that during the onset of infestation, the values of RBC, WBC, Hb, Ht showed a rise as compared with uninfested fish. Of these factors, WBC showed a steady rise, indicating the increase in the number of leucocytes during the initial stage of attck. The ESR values, however, showed a decreasing trend. Although a rise or drop in values could be observed at different levels, the ESR showed a positive slope while RBC, WBC, Hb and Ht showed negative slopes when infestation increased to over 800, indicating disease manifestation in fish. Such a trend in values was noticed by ~~krishnan et al. (1984) in ~iodo~ ~ystr~~infested by the cestode parasite ~mnorhynch~ gigas. The averge values of oxygen consumption, ammonia excretion, ammonia quotient and random activity of uninfested and infested fish are given in Table 1. As seen from the table, the values generally increased during the onset of infestation. In the case of multiple infestation, oxygen consumption showed a negative correlation with random activity while ammonia excretion and ammonia quotient followed a positive trend. However, in the case of Liza tade a negative trend was reported by Rajagopalaswamy (1985).
234
8.5 -
6.5 l-8
1.2
.
1.0
mu6
3
:I’ll: /
2 1.8
5
t
1.4
1
I
0
8
I-200
I
I
I
201-400 LO%630 601-800 > BOO
INF~CTIO~
LEVEL
Fig. 1. Haematological parameters in relation to different levels of infest&ion in My&us gulio. TABLE 1 Activity and metabolic rates in uninfested and infested Mystus gulio Levels of infestation
l-i00 101-200 201-300 301-400 401-500
Activity
Routine O2 consumption
Routine ammonia excretion
Routine a~onia quotient
25.350 -t 7.93
219.191 I!I26.74
13.588 k 1.77
0.0513 kO.014
56.260 I!Z10.20 35.639 rt: 9.91 2.313 + 0.43* 2.421 rt 0.86 4.oooi 1.16
301.997 r_+ 28.44 219.192 rir50.67 407.586 I!I64.12 370.292 rtr50.14 319.709 rt:40.66**
31.745 ?I 4.25** 27.385 rt 0.96 14.852 It 1.79 24.168 I: 2.21 33.6’I6 + Z&B**
0.1192rf:0.020 0.1880 + 0.780 0.0330 LO.003 0.0620 i 0.010 0.1092 f 0.010
**p
The authors are thank~l to Dr. G. Jagatheesan, Dean in charge, Fisheries College, Tuticorin, for his encouragement and-support.
REFERENCES Radhakrishnan, S., Nair, N.B. and Balasubramanian, N.K., 1984. Gymnorhynchus gigas Plerocercoid (Cestoda: Gymnorhynchidae) . Infection of the liver of Diodon hystrix (Pisces: Diodontidae)). Haematological changes in infected fish. Fisch und Umwelt, 13: 27-39. Rajagopalaswamy, C.B.T., 1985. Studies on parasites of mullet, Liza tade (Forskal) with special reference to host-parasite relationship. M.F.Sc. Thesis, TNAU, Coimbatore, India.