or powdered algae on growth and energy distribution in sea cucumber Apostichopus japonicus (Selenka) (Echinodermata: Holothuroidea)

Aquaculture 256 (2006) 457 – 467 www.elsevier.com/locate/aqua-online

The influence of diets containing dried bivalve feces and/or powdered algae on growth and energy distribution in sea cucumber Apostichopus japonicus (Selenka) (Echinodermata: Holothuroidea) Xiutang Yuan a,b , Hongsheng Yang a,⁎, Yi Zhou a , Yuze Mao a , Tao Zhang a , Ying Liu a a

Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, P. R. China b National Marine Environmental Monitoring Center, Dalian, 116023, P. R. China

Received 28 February 2005; received in revised form 22 January 2006; accepted 25 January 2006

Abstract In recent years, bivalve feces and powdered algae have been used as the food sources of holothurians in China. In this study, growth and energy budget for sea cucumber Apostichopus japonicus (Selenka) with initial wet body weights of 32.5 ± 1.0g (mean ± SE, n = 45) when fed with five different granule diets containing dried bivalve feces and/or powdered algae in water temperature 13.2–19.8°C and salinity 30–32 ppt were quantified in order to investigate how diets influence growth and energy distribution and to find out the proper diet for land-based intensive culture of this species. Results showed that diets affected the food ingestion, feces production, food conversion efficiency and apparent digestive ratios, hence the growth and energy budget. Sea cucumbers fed with dried feces of bivalve showed poorer energy absorption, assimilation and growth than individuals fed with other four diets; this could be because feces-drying process removed much of the benefits. Dried bivalve feces alone, therefore, were not a suitable diet for sea cucumbers in intensive cultivation. The mixed diets of feces and powered algae showed promising results for cultivation of sub-adult Apostichopus japonicus, while animals fed with powdered algae alone, could not obtain the best growth. According to SGR of tested animals, a formula of 75% feces and 25% powdered algae is the best diet for culture of this species. Extruded diets were used in the present experiment to overcome shortcomings of the traditional powdered feeds, however, it seems a conflict exists between drying bivalve feces to form extruded diets and feeding sea cucumbers with fresh feces which contain beneficial bacteria. Compared with other echinoderms, in holothurians the energy deposited in growth is lower and the energy loss in feces accounts for the majority of the ingested energy. Such detailed information could be helpful in further development of more appropriate diets for culture of holothurians. © 2006 Elsevier B.V. All rights reserved. Keywords: Sea cucumber (Apostichopus japonicus Selenka); Bivalve feces; Powdered algae; Extruded diet; Growth; Energy budget; Intensive culture

1. Introduction

⁎ Corresponding author. Tel./fax: +86 532 82898582. E-mail addresses: [email protected] (X. Yuan), [email protected] (H. Yang). 0044-8486/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.aquaculture.2006.01.029

With great demand for beche-de-mer in the world, the increasing harvest pressure on natural populations of sea cucumbers has created severe overfishing throughout the world (Hamel et al., 2001; Conand, 2004; Uthicke,

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2004). Depletion of natural stocks, together with high commercial value has encouraged stock enhancement and aquaculture programs for holothurians (Conand and Byrne, 1993; Battaglene, 1999; Battaglene et al., 1999; Conand, 2004). Sea cucumber Apostichopus japonicus (Selenka) (Liao, 1980) (= Sticopus japonicus (Selenka)) belongs to Echinodermata, Holothuroidea, Aspidochirotida, an epibenthic, temperate species, which has long been exploited as an important fishery resource in Russia, China, Japan and North and South Korea (Sloan, 1984). Successful hatching of A. japonicus juveniles in 1980s facilitated stock enhancement and aquaculture in Japan and China (see Sui, 1988; Zhang and Liu, 1998). Stock enhancement, through the release of hatcheryreared juveniles, has been suggested as a good solution to restore depleted populations (YSFRI, 1991; Yanagisawa, 1996, cited in Battaglene and Seymour, 1998). Besides, effective aquacultural methods, such as pen culture and pond culture (Sui, 1988; Chen, 2004) have been developed in the last decades for sea cucumbers in China and Japan, providing much more production in worldwide beche-de-mer trade. It was estimated that the total production of A. japonicus in northern China reached over 6750 tons (dry weight) in 2003 (Chen, 2004). Land-based intensive culture — a new promising cultural method of this animal, however, has not been drawn much attention so far (Chang, 2003; Kang et al., 2003).One of the problems encountered in this cultural method is that there is no proper diet. Previous studies about nutrition and artificial diets were focused on larvae and juveniles of A. japonicus (Sui et al., 1986; Sui, 1988; Sui, 1989). However, very few studies were conducted for sub-adult sea cucumber, especially in intensive culture. Deposit-feeding holothurians ingest sediment bearing organic matter, including bacteria, prozotoa, diatoms, and detritus of plants or animals (Choe, 1963; Yingst, 1976; Moriarty, 1982; Zhang et al., 1995). A. japonicus preferentially inhabits the bottom in flourishing large algae, rich detritus of which provide sea cucumber with main organic nutrient (Li et al., 1994; Zhang et al., 1995). In the practice of hatcheryproduced juveniles, newly settled larvae were commonly fed with diatoms and then in nursery tanks powdered algae were added for holothurian juveniles (Sui, 1988; Battaglene et al., 1999). So that it is appropriate to use powdered algae as food source for sea cucumbers. Recent studies also have shown that the food residue and feces of marine animals, and even sea cucumber's own feces, in which an increase of suitable bacteria has

occurred, are also important to nutrients of sea cucumbers (Hauksson, 1979; Tiensongrusmee and Pontjoprawiro, 1988; Goshima et al., 1994; Ramofafia et al., 1997; Yang et al., 2001; Kang et al., 2003). In the past decades, the worldwide bivalve mariculture industry has developed rapidly, especially in China. Bivalves, such as mussel, oyster and scallop etc., are active filter-feeders. They possess highly efficient filtering mechanisms which enable them to concentrate a large amount of phytoplankton and other suspended particulate matter from the pelagic system and reject undigested organic and inorganic material as faeces and pseudofaeces (collectively termed biodeposits; Haven and Morales-Alamo, 1966). Studies have demonstrated that dense populations of bivalves in shallow water can produce a large amount of biodeposits (Zhou, 2000; Mao, 2004). It has been found that A. japonicus can survive well, cultured on the substrate in bivalve culture areas (Wang et al., 1989; Li and Mou, 1996). Later, Yang et al., 2001 demonstrated that A. japonicus could utilize feces and pseudofeces of Zhikong scallop Chlamys farreri and grew well in simulated polyculture system. Recently, Zhou et al. (2006) and Yuan (2005) found that the deposit feeder Apostichopus japonicus could be co-cultured and grew well with bivalves in suspended lantern nets. Bivalve feces could also be accumulated and used as a potential food source for culture of sea cucumbers. In fact, many culturists in northern China have used bivalve feces as part of food for sea cucumbers in practice for many years. Energy budget provides a framework for evaluation of various ways in which nutrients are utilized (Lawrence and Lane, 1982). There were relatively few energy budget models proposed for echinoderms. Most were incomplete in one or more factors or ignored the effect of variables (Lawrence, 1984). Recently, because of commercial interest for echinoderms, more and more studies on diet nutrition in terms of energy utilization and digestive physiology in sea urchins have been conducted (González et al., 1993; Fernandez and Pergent, 1998; Floreto et al., 1996; Klinger et al., 1994; McBride et al., 1998; Meidel and Scheibling, 1999; Vadas et al., 2000; Otero-Villanueva et al., 2004). However, to author's knowledge, little information is available regarding growth and energy budget in sea cucumber (e.g. Hu, 2004). This study investigated how growth was influenced and energy was ingested, assimilated and allocated when sea cucumber A. japonicus were fed with five different diets made from dried feces of bivalve and/or powdered algae and thus determined the proper diet for land-based intensive culture of this species.

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2. Materials and methods 2.1. Animal source and acclimation The experiment was carried out from May 2th to June 16th, 2003 in the laboratory at Institute of Oceanology, Chinese Academy of Sciences, Qingdao, P. R. China. Sea cucumbers used in this study were collected in April from the coast of Jiaonan, Qingdao, where the temperature was 11.3 °C. Prior to the experiment, animals were transferred to the laboratory in fiberglass aquaria and acclimated for 6d during which they were fed with diet C (see below) once per day with excess of feed (at about 16:30 h) to retain similar initial biochemical composition and physical activity between experiment animals. 2.2. Diets preparation The five diets used in the experiment were: diet A — dried feces of bivalve; diet B — 75% dried feces and 25% powdered algae; diet C — 50% dried feces and 50% powdered algae; diet D — 75% dried feces and 25% powdered algae; diet E — powdered algae. Bivalve feces were collected using traps in Sanggou Bay, near Rongcheng City, Shandong Provience, China. The cultured bivalves (including Zhikong Scallop C. farreri, Pacific Oyster Crassostrea gigas, Bay Scallop Argopecten irradians, and Japanese Scallop Patinopecten yessoensis) were fed with natural microalgae in the field (for more detail about method and process please refer to Zhou (2000) and Mao (2004)). Bivalve feces were dried at 65 °C, ground and sieved using 0.18 to 0.20 mm mesh. Powdered algae, which were made from macroalgae containing Laminaria japonica, Sargassum thunbergii and Sargassum sp. was commercially available for cultivating larvae and juvenile sea cucumbers from Liaoning Marine Fisheries Research Institute, Dalian, Liaoning Province, China. These macroalgae were finely grained below 0.08 mm

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and then fermented. Bivalve feces and powdered algae were well mixed to the given proportions, slightly watered, stirred, extruded by meat grinder to cylindrical form: 3.64 ± 0.02 mm (mean ± SE, n = 30) diameter and 5–20 mm length, then dried at 65 °C for 36 h and stored at 4 °C for use. The extruded diets sink easily because of high specific gravity and become sedimentlike in 5 to 10 min after sinking to the bottom of tanks. The feces of holothurians are well structured and it is easy to separate the uneaten food and the feces from the bottom of the tanks because the leftover food in aquaria is sediment-like. Proximate composition of the diets is listed in Table 1. 2.3. Experiment design After 2 d starvation, 45 sea cucumbers with initial wet body weights of 32.5 ± 1.0 g (mean ± SE) were randomly selected from acclimatized animals and placed in equal number into 15 fiberglass aquaria (50 × 50 × 40 cm3 ) to form 5 groups in triplicate. The 5 groups were fed with different diets of A, B, C, D and E, respectively. A complete randomized block design was used to arrange the 15 aquaria of 5 treatment groups. 2.4. Rearing conditions During the experiment, aeration was provided continuously and one-half volume of water was exchanged every day to ensure the water quality. Seawater used in the experiment was filtered by composite sand filter. Seawater temperatures increased from 13.2 °C in the beginning to 19.8°C in the end. They were similar in all tanks and not artificially controlled, with diurnal variation being ± 0.5 °C. Dissolved oxygen was maintained above 5.0mg L− 1; the levels of ammonia in the water of aquaria were less than 0.25mg L− 1. Other conditions were pH 7.8–8.2; salinity 30–32ppt; photoperiod 13L: 11D.

Table 1 Proximate composition of five experimental diets (mean ± SE) Diets

A B C D E a b

Proximate composition Dry matter (%)

Protein (%)a

Lipid (%)a

Ash (%)a

Energy (J g− 1)b

98.97 ± 0.02 98.82 ± 0.01 98.77 ± 0.11 98.70 ± 0.09 98.61 ± 0.13

1.40 ± 0.16 3.33 ± 0.15 6.27 ± 0.07 8.87 ± 0.00 11.03 ± 0.10

0.36 ± 0.05 0.79 ± 0.01 1.06 ± 0.06 1.30 ± 0.09 1.65 ± 0.06

92.02 ± 0.02 78.42 ± 0.03 64.89 ± 0.01 50.80 ± 0.06 36.73 ± 0.02

68.4 ± 1.7 2668.8 ± 12.1 5260.8 ± 1.0 8141.1 ± 8.3 10755.8 ± 61.8

Protein, lipid and ash were percentage of dry matter basis. Energy was calculated in dry sample.

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Table 2 Initial and final wet weight, dry weight of Apostichopus japonicus for five diet treatments (mean ± SE). Parameters

Initial weight Final weight

Diet treatments

WW (g) DW (g) WW (g) DW (g)

A

B

C

D

E

30.1 ± 2.7 2.3 ± 0.2 22.4 ± 2.6a 1.8 ± 0.2a

30.9 ± 1.4 2.3 ± 0.1 67.7 ± 3.8b 4.9 ± 0.3b

33.3 ± 2.3 2.5 ± 0.2 59.2 ± 4.0b 4.3 ± 0.3b

33.7 ± 2.7 2.6 ± 0.2 56.7 ± 7.6b 4.4 ± 0.5b

33.9 ± 3.0 2.6 ± 0.2 56.8 ± 6.6b 4.1 ± 0.5b

WW: wet weight; and DW: dry weight. Values with different letters in the same column were significantly different from each other (n = 3, ⁎P b 0.05).

2.5. Procedure and sample collection Fifteen sea cucumbers were sampled from the acclimated animals simultaneously while experimental animals were selected to determine the initial body composition of the experimental animals. During the experiment, sea cucumbers were fed once per day with excess of feed in aquaria (at about 16:30 h). Uneaten feed was siphoned 24 h later from aquaria and dried at 65°C to constant weight for calculation use. Animal feces were also collected by siphon twice per day (at 8:00 and 16:00 h). The feces were dried at 65 °C to constant weight and those from each aquarium were pooled for further analysis. At the end of 35 d experiment, all the test animals were deprived of food to clear their guts for 2 d, weighed, and then dried at 65 °C until constant weight was achieved. The animals from the same aquaria were pooled as one sample and there were 15 samples in total. 2.6. Data calculation The energy content of the diets, feces and animal samples was measured by PARR1281 Calorimeter (PARR Instrument Company, Moline, IL, USA). The

Specific growth rate (%.day-1)

2.5

N content was determined by Perkin-Elmer 240C Elemental Analyzer (Perkin-Elmer Inc., Wellesley, MA, USA). Proximate composition of diets was analyzed according to AOAC (1990). All the analysis but N content were conducted in duplicate. Specific growth rate (SGR), ingestion rate (IR), feces production rate (FPR), food conversion efficiency (FCE) and apparent digestive ratio (ADR) were calculated as follows: SGR (% d− 1) = 100(lnW2 − lnW1) T −1; IR (g g− 1 d− 1) = C / [T(W2 + W1) / 2]; FPR (g g− 1 d− 1) = F / [T (W2 + W1) / 2]; FCE (%) = 100(W2 − W1) / C; ADR (%) = 100(C − F) / C; where, W1 and W2 are initial and final dry body weight of sea cucumbers in each aquarium; T, the duration of the experiment (35 d); C is the dry weight of food consumed, and F is the dry weight of feces. Energy budget was constructed according to the equation: C = G + F + U + R, where, C is energy consumed; G is energy for growth; F represents energy of feces produced; U is energy loss as ammonia

c

2

b

b b

1.5 1 0.5 0 dietA

dietB

dietC

dietD

dietE

-0.5 -1

a Diet treatments

Fig. 1. Specific growth rates (SGR) of Apostichopus japonicus during 35d experiment. Means (n = 3) with different letters indicate significant differences (⁎P b 0.05), and bars represent standard errors of the means.

X. Yuan et al. / Aquaculture 256 (2006) 457–467

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3

Ingestion rate (g.g-1.day-1)

c 2.5 2 1.5

b

1

a

a

dietC

dietD

a

0.5 0 dietA

dietB

dietE

Diet treatments Fig. 2. Ingestion rates (IR) of A. japonicus during the 35 d experiment. Means (n = 3) with different letters indicate significant differences (⁎P b 0.05), and bars represent standard errors of the means.

excretion; and R stands for energy lost as respiration. The estimation of U was based on the nitrogen budget equation: U = (CN − GN − FN) × 24,830 (Wang et al., 2003), where CN is the nitrogen consumed from food; FN, the nitrogen lost in feces; GN, the nitrogen deposited in animal body; 24,830, the energy content in excreted ammonia (J g− 1 ). The value of R was calculated as the following energy budget equation: R = C − G − F − U. Other physiological parameters were calculated as follows: Ab, absorbed energy (Ab = P + R + U = C − F): As, assimilated energy (As = P + R = C − F − U = Ab − U). 2.7. Statistical analysis Statistics was performed using software SPSS11.0 with possible differences among diet treatments being tested by one-way ANOVA. Duncan's multiple range tests were used to test the differences among treatments.

Differences were considered significant at a probability level of 0.05. 3. Results 3.1. Growth At the beginning of the experiment, there were no significant differences in wet and dry body weights of test sea cucumbers among diet treatments (P N 0.05) (Table 2). At the end of the experiment, final wet and dry body weights of test animals fed with diet A was significantly lower than those fed with other diets (⁎P b 0.05), and no significant differences existed among other four treatments in wet weight and dry weight (P N 0.05) (Table 2). SGR of the test sea cucumbers varied in different diet treatments and showed a descending order of diet B N diet D N diet C N diet E N diet A. The significantly

Feces production rate (g.g-1.day-1)

3 2.5

c

2 1.5

b 1

a

a

a

dietD

dietE

0.5 0 dietA

dietB

dietC

Diet treatments Fig. 3. Feces production rates (FPR) of A. japonicus during the 35d experiment. Means (n = 3) with different letters indicate significant differences (⁎P b 0.05), and bars represent standard errors of the means.

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Food conversion efficiency (%)

3

c

2.5

bc

bc

b

2 1.5 1 0.5 0 dietA

dietB

dietC

dietD

dietE

a

-0.5

Diet treatments Fig. 4. Food conversion efficiencies (FCE) of A. japonicus during the 35d experiment. Means (n = 3) with different letters indicate significant differences (⁎P b 0.05), and bars represent standard errors of the means.

lowest SGR occurred in diet A treatment with negative values. Meanwhile, no significant differences in SGR were found among treatments of diet C, diet D and diet E, but all were significantly different from treatments of diet B (⁎P b 0.05) (Fig. 1). 3.2. Ingestion rate and feces production rate Ingestion rate (IR) (Fig. 2) and feces production rate (FPR) (Fig. 3) showed the same descending trend as diet A N diet B N diet C N diet D N diet E. Duncan's multiple range tests showed that there were no significant difference in IR and FPR among treatments of diet C, diet D and diet E (P N 0.05), but all were significantly different with diet A or diet B treatment (⁎P b 0.05). Significant differences were also found between treatments of diet A and diet B (⁎P b 0.05).

3.3. Food conversion efficiency Food conversion efficiency (FCE) is presented in Fig. 4. FCE of diet A treatment were negative and significantly lower than those under other four diet treatments (⁎P b 0.05). No significant differences were found among other four diet treatments in FCE (P N 0.05). 3.4. Apparent digestive ratio Apparent digestive ratio (ADR) was shown in ascending order of diet A b diet B b diet C b diet D b diet E, and Duncan's multiple range tests showed that there were significant differences among them in ADR (⁎P b 0.05) with the exception of that between diet C and D or diet D and E (P N 0.05) (Fig. 5).

Apparent digestive ratio (%)

35

d cd

30

c

25 20

b 15 10

a

5 0 dietA

dietB

dietC

dietD

dietE

Diet treatments Fig. 5. Apparent digestive ratios (ADR) of A. japonicus during the 35d experiment. Means (n = 3) with different letters indicate significant differences (⁎P b 0.05), and bars represent standard errors of the means.

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3.5. Energy budget Energy parameters and energy budget of the test sea cucumbers fed with five diets are presented in Tables 3 and 4. Energy intake by the test animals fed with diet A was significantly lower (251.1 J g− 1 d− 1) than with other four diets (3133.6–6676.2 J g− 1 d− 1). The energy loss in feces of test animals fed with diet A was 206.2J g− 1 d− 1, accounting for 94.6% of the total energy consumed. Although energy loss in feces of test animals fed with other four diets were significantly higher (1888.8– 4479.9 J g− 1 d− 1) than that of test animals fed with diet A, they only accounted for 55.6–67.1% in energy consumed. This is why the absorbed energy (Ab) of the test animals fed on diet A was significantly lower (8.9 J g− 1 d− 1) than that fed on other four diets (1244.8– 2196.3 J g− 1 d− 1). The assimilated energy (As) of the test animals fed with diet Awas negative (−64.5J g− 1 d− 1) and significantly lower than that of sea cucumbers fed with other four diets (1160.4–2068.6 J g− 1 d− 1). Sea cucumbers fed with other four diets, however, showed a similar energy allocation. The energy deposited for growth was 5.5–7.9%; energy loss in feces was between 55.6–67.1%, and energy loss for excretion and respiration was 2.4–2.7% and 24.6–35.5%, respectively. No significant differences among allocation of energy in sea cucumbers fed with diet B, C, D, and E were found (P N 0.05). 4. Discussion 4.1. Ingesting and growth of sea cucumbers Ingestion rates of sea cucumber were significantly affected by diets; a negative relationship was revealed between IR and the protein level or energy content. In natural ecosystem, sediment of low nutritional value ingested by deposit feeders means those animals need to

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ingest large amounts of sediment in order to gain a net input of energy (Santos et al., 1994; Hudson et al., 2004). Vise versa, when food quality becomes better, in certain season for example, internal appetite regulation would work actively to decrease food ingestion. The same phenomenon was also found in other echinoderms. A report found that in sea urchin Strongylocentrotus franciscanus, prepared diets of different protein levels resulted in different IR (McBride et al., 1998). OteroVillanueva et al. (2004) also found in the regular echinoid Psammechinus miliaris that lowest ingestion rate was related to high energetic diet. Result showed that the quality of diets also affected FCE and ADR in A. japonicus. Therefore, the growth of the animal was affected by different diets through the interaction of IR, FCE and ADR. Previous studies showed that sea cucumber A. japonicus grew gradually when living on fresh bivalve feces in the wild. The average growth rates were 0.17, 0.21 and 0.28 g wet weight d− 1 for initial wet body sizes of 41.7 ± 7.3, 55.9 ± 11.3 and 79.0 ± 16.3g ind− 1 (mean ± SD), respectively in Sishili Bay of China (Zhou, in press) and the SGRw (SGR in wet weight) were 0.25–0.34 and 0.18–0.29% d− 1 for initial wet body sizes of 6.19–7.12 and 21.03–29.88 g ind− 1, respectively, in Sangou Bay, China (Yuan, 2005). However, in the present study, SGR was only − 0.66% d− 1 in dried bivalve feces (diet A) treated group. Sea cucumbers fed with dried bivalve feces had a negative growth, this could be because that feces-drying process (65 °C for 36 h) removed much of the benefits (e.g. bacteria, vitamins and fatty acids). Sole dried bivalve feces, therefore, were not suitable for diet of sea cucumbers in intensive cultivation. The mixed diets of feces and powered algae showed promising results for cultivation of sub-adult Apostichopus japonicus. SGR of test animals were from 1.31% to 2.13% d− 1 in powdered algae (diet E) and mixed diets treated groups (diet B, C and D). Powdered algae have

Table 3 Energy parameters of A. japonicus fed with different diets during 35d experiment Energy parameters C (J g− 1 d− 1) F (J g− 1 d− 1) U (J g− 1 d− 1) R (J g− 1 d− 1) G (J g− 1 d− 1) Ab (J g− 1 d− 1) As (J g− 1 d− 1)

Diet treatments A

B

C

D

E

215.1 ± 15.9a 206.2 ± 53.3a 70.3 ± 12.6a 108.2 ± 20.8a − 169.7 ± 29.2a 8.9 ± 37.4a − 64.5 ± 50.0a

3133.6 ± 96.3b 1888.8 ± 187.4b 84.5 ± 5.3ab 933.8 ± 135.5b 226.5 ± 34.12b 1244.8 ± 100.5b 1160.4 ± 104.8b

3833.5 ± 341.2b 2135.3 ± 203.1bc 93.0 ± 7.0ab 1360.1 ± 136.0bc 245.2 ± 18.1b 1698.2 ± 148.7bc 1605.2 ± 141.7bc

5122.3 ± 698.7c 2932.2 ± 417.0c 121.5 ± 15.4b 1669.9 ± 258.6c 398.7 ± 44.4c 2190.1 ± 302.9c 2068.6 ± 287.9c

6676.2 ± 36.5d 4479.9 ± 197.5d 181.3 ± 12.5c 1664.3 ± 184.8c 370.7 ± 17.8c 2196.3 ± 190.6d 2015.0 ± 192.3c

Values (expressed as mean ± SE, n = 3) with different letters in the same column were significantly different from each other (⁎P b 0.05). C: energy ingested; F: energy lost in feces; U: energy lost in excretion; R: energy lost in respiration; G: energy deposited as growth; Ab: absorbed energy (Ab = P + R + U = C − F); As: assimilated energy (As + P + R = C − F − U = Ab − U).

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Table 4 Energy allocation of A. japonicus fed with different diets during 35d experiment Diets A B C D E

C

G (%C − 1)

F (%C − 1)

100 100 100 100 100

− 78.3 ± 7.8 7.2 ± 0.9b 6.4 ± 0.4b 7.9 ± 0.5b 5.5 ± 0.2b a

U (%C − 1) b

94.6 ± 17.8 60.0 ± 4.4a 55.6 ± 1.2a 57.1 ± 1.9a 67.1 ± 2.9a

b

32.4 ± 3.5 2.7 ± 0.1a 2.4 ± 0.1a 2.4 ± 0.0a 2.7 ± 0.2a

R (%C − 1) 51.3 ± 13.5b 30.1 ± 5.3a 35.5 ± 1.4ab 32.6 ± 2.2a 24.6 ± 2.8a

Values (expressed as mean ± SE, n = 3) with different letters in the same column were significantly different from each other (⁎P b 0.05). C is the energy consumed in food; G, the energy deposited for growth; F, the energy lost in feces; U, the energy lost in excretion and R, the energy loss for respiration.

been used in the hatchery-produced juveniles of A. japonicus and Holothuria scabra for a long time in China, Japan, India and Indonesia (Sui, 1988; Battaglene et al., 1999). Yingst in 1976 indicated that many depositfeeding holothurians have little cellulose activity in their gut and did not appear to assimilate macroalgae before it was decomposed by bacteria and fungi. Battaglene et al. (1999) suggested that powdered algae (Riken Vitamin, Tokoyo, a powdered brown algae production) was not a major source of food for juveniles and adding algae was only beneficial at high densities. Powdered algae used in the present study were fermented and many hatching and sub-adult culturing practices have showed that it works for feeding sea cucumbers. Animals fed with powdered algae or mixed diets grew well, indicating that fermented powdered algae could be good food for sea cucumbers. On the other hand, animals fed with pure powdered algae could not obtain the best growth, showing that feces of bivalve may provide certain nutrients or digestion

regulators to the animals, which could be some mineral components that were vital to the metabolism of sea cucumbers (Xu et al., 1999). Furthermore, SGR of animals fed with diet B (the formula of 75% dried feces and 25% powdered algae) was higher than those fed with powdered algae (diet E) and other mixed diets (diet C and D), indicating that this formula could be better for intensive cultivation of sea cucumbers. 4.2. Merits of extruded feeds Aspidochirote holothurians are deposit-feeders. The physical characteristics of feed used for these animals in aquaculture should be sediment-like, so traditional form of feeds was powder (e.g. Sui et al., 1986; Sui, 1988; Sui, 1989). This form of diets suffers from some significant shortcomings. Firstly, it is difficult to sink to the bottom of tank because of low specific gravity, and some food items may easily react with the water medium and are quickly degraded, which results in big loss of feed. Also, from the environmental point of view it can be highly polluting, thus generating poor environmental conditions. In the present experiment, we mixed powdered algae and dried bivalve feces and extruded to granule shape. Extruded feeds were of higher specific gravity and more stable than powdered feeds, so they sink easily. No binder was added to feeds and they become sediment-like in 5to 10min after sinking to the bottom of tanks. The physical characteristics of granule shape feeds not only adapt to holothurians' deposit-feeding behavior, but also overcome above shortcomings of powdered feeds. However, there seems to be a conflict between drying bivalve feces to form extruded diets and feeding sea

Table 5 Energy budgets of some echinoderms Species

Factors

Body sizes

G F U R F+U References (%C − 1) (%C − 1) (%C − 1) (%C − 1) (%C − 1)

Sea star Leptasterias hexactis

Salinity: 30 ppt Salinity: 20 ppt Salinity: 15 ppt Algae diet Artificial diet Mussel diet Salmon diet Algae diet Mussel diet Salmon diet / / Bivalve feces Powdered algae and mixed diets

DW: 0.4g DW: 0.6g DW: 0.3g TD: 8–16mm TD: 8–16 mm TD: 8–16 mm TD: 8–16 mm TD: 29–37mm TD: 29–37mm TD: 29–37mm WW: 3.7g WW: 31–70g WW: 32.5 ± 1.0g WW: 32.5 ± 1.0g

28.1 11.3 − 284.0 12.3 70.1 77.7 62.6 12.8 31.0 26.7 11.4 7.9 −78.3 6.8

Sea urchin Psammechinus miliaris

Sea cucumber Apostichopus japonicus Sea cucumber Apostichopus japonicus

TD: test diameter; DW: dry weight; WW: wet weight.

35.5 52.2 32.0

67.8 74.3 94.6 60.0

4.7 6.4 63.0

0.4 0.4 32.4 2.5

31.7 29.9 289.0 1.5 0.2 0.4 0.3 0.2 0.2 0.2 20.4 17.4 51.3 30.7

Shirley and Stickle, 1982

86.2 29.7 21.9 37.1 87 68.8 73.1

Otero-Villanueva et al., 2004

Hu, 2004 This study

X. Yuan et al. / Aquaculture 256 (2006) 457–467

465

cucumbers with fresh feces, in which abundant bacteria beneficial to holothurians are present.

National Natural Science Foundation of China (No. 40576073).

4.3. Energy budget

References

Sea cucumbers fed with dried feces of bivalve showed poorer energy absorption, assimilation and growth than individuals fed with other four diets. The test animals fed with diet A spent much more energy in feces, excretion and respiration, while depositing less energy for growth than those animals fed with other four diets. The diet A is a low energy feed and the amount of energy ingested by sea cucumbers did not fulfill the energy loss in feces, excretion and respiration, so they had to employ energy deposited in the body before. For other treatments, no significant differences among allocation of energy in sea cucumbers fed with diet B, C, D, and E were found (P N 0.05) (Table 4). The average energy budget in sea cucumbers fed with the four diets was: 100C = 6.8G + 60.0F + 2.5U + 30.7R. Compared with other echinoderms (Table 5) and fishes (such as general budget equation of herbivorous fish: 100C = 20G + 41F + 2U + 37R or carnivorous fish: 100C = 29G + 20F + 7U + 44R (Brett and Groves, 1979, cited in Cui, 1989)), the point of energy budget in holothurians was that the energy deposited in growth was lower (values range from − 78.3% to 6.8% in the present study and 7.9% to 11.4% in Hu (2004) and the energy loss in feces accounted for the majority of the ingestion energy (values range from 56.0–94.6% in the present study and 67.8–74.3% in Hu (2004)). This is adapted to food sources and feeding mechanisms of holothurians. No specialized organs for physical grind and no specialized gland for chemical digestion (Massin, 1982) with low activity of digestive enzymes in the main food digestion part (i.e. mid-gut and hint-gut) (Yingst, 1976; Sibuet and Khripounoff, 1982; Cui et al., 2000) made holothurians have a low digestive efficiency (Apparent digestive ratios were only from 6.08% to 28.75% in the present study). Higher percentage of energy lost in feces would result in a lower percentage of energy deposition in growth of holothurians than of Asteroids and Echinoids. Acknowledgements We would like to thank Xuefei Wang, Quan Liu and Dr. Chunxiao Zhang for their assistance in experiment performing and sample analysis. In particular, we would like to thank Dr. Roger Z. Yu and two anonymous reviewers for professional revision of the manuscript. This study was funded by National Key Foundational Research Project of China (No. G1999012012) and

Association of Official Analytical Chemists (AOAC), 1990. Official methods of analysis. In: Helrich, K. (Ed.), Association of Official Analytical Chemists, 15th ed., p. 1298 (Arlington, VA, USA). Battaglene, S.C., 1999. Culture of tropical sea cucumbers for the purposes of stock restoration and enhancement. Naga 22, 4–11. Battaglene, S.C., Seymour, J.E., 1998. Detachment and grading of the tropical sea cucumber sandfish, Holothuria scabra, juveniles from settlement substrates. Aquaculture 159, 263–274. Battaglene, S.C., Seymour, E.J., Ramofafia, C., 1999. Survival and growth of cultured juvenile sea cucumbers Holothuria scabra. Aquaculture 178, 293–322. Chang, Z., 2003. Cultural methods and techniques of sea cucumbers. Shandong Fisheries 20 (1), 23 (in chinese, with english abstract). Chen, J., 2004. Present status and prospects of sea cucumber industry in China. In: Lovatelli, A., Conand, C., Purcell, S., Uthicke, S., Hamel, J.-F., Mercier, A. (Eds.), Advances in Sea Cucumber Aquaculture and Management. FAO, Rome, pp. 25–38. Choe, S., 1963. Study of Sea Cucumber: morphology, Ecology and Propagation of Sea Cucumber. Kaibundo Publishing House, Tokyo, Japan, p. 219. Conand, C., 2004. Present status of world sea cucumber resources and utilization: an international overview. In: Lovatelli, A., Conand, C., Purcell, S., Uthicke, S., Hamel, J.-F., Mercier, A. (Eds.), Advances in Sea Cucumber Aquaculture and Management. FAO, Rome, pp. 13–23. Conand, C., Byrne, M., 1993. A review of recent developments in the world sea cucumber fisheries. Mar. Fish. Rev. 55, 1–13. Cui, L., Dong, Z., Lu, Y., 2000. Histological and histochemical studies on the digestive system of Apostichopus japonicus. Chinese J. Zool. 35, 2–4 (in Chinese, with English abstract). Cui, Y., 1989. Bioenergetics of fishes: theory and methods. Acta Hydrobiol. Sin. 13, 369–383 (in chinese, with english abstract). Fernandez, C., Pergent, G., 1998. Effects of different formulated diets and rearing conditions on growth parameters in the sea urchins Paracentrotus lividus. J. Shellfish Res. 17, 1571–1581. Floreto, E.A.T., Techima, A., Ishikawa, M., 1996. The effects of seaweed diets on the growth, Lipid and fatty acid of juvenile of the white sea urchin Tripneustes gratilla. Fish. Sci. 62, 589–593. González, M.L., Pérez, M.C., López, D.A., Pino, C.A., 1993. Effects of algal diet on the energy available for growth of juvenile sea urchins Loxechinus albus (Molina, 1782). Aquaculture 115, 87–96. Goshima, S., Fujiyoshi, Y., Ide, N., Gamboa, R.U., Nakao, S., 1994. Distribution of Japanese common sea cucumber, Stichopus japonicus in lagoon Saroma. Suisanzoshoku 42, 261–266 (in Japanese, with english abstract). Hamel, J.-F., Conand, C., Pawson, D.L., Mercier, A., 2001. The sea cucumber Holothuria scabra (Holothuroidea, Echinodermata): its biology and exploitation as Beche-de-Mer. Adv. Mar. Biol. 41, 131–202. Hauksson, E., 1979. Feeding biology of stichopus tremulus, a depositfeeding holothurian. Sarsia 64, 155–160. Haven, D.S., Morales-Alamo, R., 1966. Aspects of biodeposition by oysters and other invertebrate filter feeders. Limnol. Oceanogr. 11, 487–498. Hu, G., 2004. Primary research on artificial food and energy budget of Sea Cucumber (Apositiehopus japonicus). Master thesis.

466

X. Yuan et al. / Aquaculture 256 (2006) 457–467

Dalian Fisheries University. 43pp (in Chinese with English abstract). Hudson, I.R., Wigham, B.D., Tyler, P.A., 2004. The feeding behavior of a deep-sea holothurian, Stichopus tremulus (Gunnerus) based on in situ observation and experiments using a remotely operated vehicle. J. Exp. Mar. Biol. Ecol. 301, 75–91. Kang, K.H., Kwon, J.Y., Kim, Y.M., 2003. A beneficial coculture: charm ablone Haliotis discus Hannai and sea cucumber Sticopus japonicus. Aquaculture 216, 87–93. Klinger, T.S., Lawrence, J.M., Lawrence, A.L., 1994. Digestive characteristics of the sea urchin Lytechinus variegatus (Lamarck) (Echinodermata: Echinoidea) fed prepared feeds. J. World Aquac. Soc. 25, 489–496. Lawrence, J.M., 1984. The energetic echinoderm. Proceedings of the Fifth International Echinoderm Conference. A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 47–67. Lawrence, J.M., Lane, J.M., 1982. The utilization of nutrients by postmetamorphic echinoderms. In: Jangoux, M., Lawrence, J.M. (Eds.), Echinoderm Nutrition. A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 368–371. Li, Y., Mou, S., 1996. Study on the interspecific relationship and ecological capacity in marine animals' culture. Trans. Oceano. Limno. 1, 24–30 (in Chinese with English abstract). Li, Y., Wang, Y., Wang, P., 1994. Habitat environment and water area selection of stock increment of Apostichopus japonicus. Trans. Oceano. Limno. 4, 42–47 (in Chinese, with English abstract). Liao, Y., 1980. The Aspidochirote Holothurians of China with erection of a new genus in echinoderms: present and past. In: Jangoux, M. (Ed.), Proceeding of European Colloquium on Echinoderm. A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 115–120. Mao, Y., 2004. Effects of Bivalve Raft culture on Environment and their Ecological regulation in Sanggou Bay, China. Ph.D thesis, Ocean University of China, 146pp. (in Chinese with English abstract). Massin, C., 1982. Food and feeding mechanisms: Holothuroidea. In: Jangoux, M., Lawrence, J.M. (Eds.), Echinoderm Nutrition. A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 43–53. McBride, S.C., Lawrence, J.M., Lawrence, A.L., Mulligan, T.J., 1998. The effects of protein concentration in prepared diets on growth, feeding rate, total organic absorption, and gross assimilation efficiency of the sea urchin Strongylocentrotus franciscanus. J. Shellfish Res. 17, 1562–1570. Meidel, S.K., Scheibling, R.E., 1999. Effects of food type and ration on reproductive maturation and growth of the sea urchin Strongylocentrotus droebachiensis. Mar. Biol. 134, 155–166. Moriarty, D.J.W., 1982. Feeding of Holothuria atra and sticopus chloronotus on bacteria, organic carbon and organic nitrogen in sediments of the great barrier reef. Aust. J. Mar. Freshw. Res. 33, 255–263. Otero-Villanueva, M.M., Kelly, M.S., Burnell, G., 2004. How diets influence energy partitioning in the regular echinoid Psammechinus miliaris; constructing an energy budget. J. Exp. Mar. Biol. Ecol. 304, 159–181. Ramofafia, C., Foyle, T.P., Bell, J.D., 1997. Growth of juvenile Actinopyga mauritiana (Holothuroidea) in captivity. Aquaculture 152, 119–128. Santos, V., Billett, D.S.M., Rice, A.L., Wolff, G.A., 1994. Organic matter in deep-sea sediments from the porcupine abyssal plain in the North-east Atlantic Ocean: 1. Lipids. Deep-sea Res. 41, 789–819. Shirley, T.C., Stickle, W.B., 1982. Responses of Leptasterias hexactis (Echinodermata:Asteroidea) to low salinity II: nitrogen metabolism, respiration and energy budget. Mar. Biol. 69, 155–163.

Sibuet, M., Khripounoff, A., 1982. Modification of the gut contents in the digestive tract of abyssal holothurians. In: Lawrence, J.M. (Ed.), International Echinoderms Conference, Tampa Bay. A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 421–428. Sloan, N.A., 1984. Echinorderm fisheries of the world: a review. Echinodermata (Proceedings of the Fifth International Echinoderm Conference). A. A. Balkema Publishers, Rotterdam, Netherlands, pp. 109–124. Sui, X., 1988. Culture and Enhance of Sea Cucumber. Agriculture press, Beijing, China, pp. 54–55 (in Chinese). Sui, X., 1989. The main factors influencing the larval development and survival rate of the sea cucumber Apostichopus japonicus. Oceanologia et Limnologia Sinica 20, 314–321 (in Chinese with English abstract). Sui, X., Hu, Q., Chen, Y., 1986. A study on technology for rearing of postlarvae and juvenile of sea cucumber Apostichopus japonicus in high density tanks. Oceanologia et Limnologia Sinica 17, 513–520 (in Chinese, with English abstract). Tiensongrusmee, B., Pontjoprawiro, S., 1988. Sea cucumber culture: potential and prospect. Seafarming Development Project Manual No. 14. FAO, p. 18. Uthicke, C., 2004. Overfishing of holothurians: lessons from the Great Barrier Reef. In: Lovatelli, A., Conand, C., Purcell, S., Uthicke, S., Hamel, J.-F., Mercier, A. (Eds.), Advances in Sea Cucumber Aquaculture and Management. FAO, Rome, pp. 163–171. Vadas, R.L., Beal, B., Dowling, T., Fegley, J.C., 2000. Experimental field tests of natural algal diets on gonad index and quality in the green sea urchin Strongylocentrotus droebachiensis: a case for rapid summer production in post-spawned animals. Aquaculture 182, 115–135. Wang, F., Dong, S., Huang, G., Wu, L., Tian, X., Ma, S., 2003. The effect of light color on the growth of Chinese shrimp Fenneropenaeus chinensis. Aquaculture 228, 351–360. Wang, S., Wei, S., Tan, Z., Wang, J., Zhang, J., 1989. Culture of sea cucumber by artificial reefs on bottom of bivalve/kelp culture areas. Qilu Fisheries 21 (3), 11–13 (in Chinese, with English abstract). Xu, Z., Bi, S., Wang, J., Wang, Z., Wu, F., 1999. Effect of different feeds on growth and color-change of juvenile sea cucumbers. Shandong Fisheries 16 (1), 30–33 (in Chinese with English abstract). Yang, H., Zhou, Y., Wang, J., Zhang, T., Wang, P., He, Y., Zhang, F., 2001. A modeling estimation of carrying capacities for Chlamys farreri, Laminaria japonicus and Apostichopus japonicus in Sishiliwan Bay, Yantai. J. Fish. Sci. China 7, 27–31 (in Chinese, with English abstract). Yingst, J.Y., 1976. The utilization of organic matter in shallow marine sediments by an epibenthic deposit-feeding holothurian. J. Exp. Mar. Biol. Ecol. 23, 55–69. YSFRI (Yellow Sea Fisheries Research Institute), 1991. Training manual on breeding and culture of scallop and sea cucumber in China. Yellow Sea Fisheries Research Institute, Manual 9 of Regional Sea farming Development and Demonstration Project. Qingdao, China, pp. 47–79. Yuan, X., 2005. Studies on physio-ecology and bioremediation of sea cucumber, Apostichopus japonicus (Selenka). Ph.D thesis, Graduate School of Chinese Academy of Science. 138pp. (in Chinese with English abstract). Zhang, Q., Liu, Y., 1998. The culture and enhancement techniques of sea cucumbers and sea urchins. Qingdao Ocean University Publishing House, Qingdao, China, p. 157 (in Chinese).

X. Yuan et al. / Aquaculture 256 (2006) 457–467 Zhang, B., Sun, D., Wu, Y., 1995. Preliminary analysis on the feeding habit of Apostichopus japonicus in the rocky coast waters off Lingshan Island. Mar. Sci. 3, 11–13 (in Chinese, with English abstract). Zhou, Y., 2000. Fundamental studies on effects of raft culture of filter-feeding bivalves on coastal ecological environment. Ph.D thesis, Institute of Oceanology, Chinese Academy of Sciences. 200 pp. (in Chinese with English abstract).

467

Zhou, Y., Yang, H., Liu, S., Yuan, X., Mao, Y., Zhang, T., Liu, Y., Zhang, F., 2006. Feeding on biodeposits of bivalves by the sea cucumber Stichopus japonicus Selenka (Echinidermata: Holothuroidea) and a suspension coculture of filter-feeding bivalves with deposit feeders in lantern nets from longlines. Aquaculture 256, 510–520.