Evaluation of Potential Feed Ingredients for the Juvenile Four‐sided Sea Cucumber,Isostichopus badionotus

The objective of this study was to evaluate two seaweed species, Solieria filiformis and Macrocytis piryfera, both as dry‐meal powder and predigested meal, to be used as ingredients in artificial diets for the juvenile four‐sided sea cucumber, Isostichopus badionotus. Four diets were tested in triplicate: S. filiformis dry‐meal powder and predigested meal and M. piryfera dry‐meal powder and predigested meal, mixed with 70% of beach sand. Survival exceeded 90% in all the treatments, and there were no differences in the growth of juveniles using dry‐meal powder or predigested meal. Weight gain was calculated for all the diets, and the highest values were obtained by animals fed S. filiformis. No differences between using dry‐meal powder and predigested meal were found, so these diets were excluded from the second trial. The ingestion rate was the same with both algae, but the feed conversion ratio was twice as high for M. piryfera. Solieria filiformis exhibited a number of differences in fatty acid and amino acid profiles, including higher proline, arginine, and saturated fatty acid levels. The results indicate that S. filiformis has better nutritional characteristics to be an ingredient for an artificial I. badionotus juvenile diet.     

Evaluation of the growth and survival rate of the Caribbean Sea cucumber,Isostichopus badionotus (Selenka, 1867), early juveniles produced in captivity

Isostichopus badionotus is a new commercially important sea cucumber in the Caribbean that has rapidly shown signs of overexploitation. There is no information on the growth and survival rates for wild or hatchery‐produced early juveniles. Hatchery production and determination of juvenile growth rates are essential for future aquaculture efforts for this species. In this study, daily growth rate (GR), specific growth rate (SGR), weight gain (WG), survival rate (SR), and weight–length relation (WLR) were evaluated using small (0.01 g) and large (0.25 g) hatchery‐produced early juveniles under laboratory conditions. Growth was rapid compared to other cultured sea cucumber species; maximal values of SGR and WG were obtained for small juveniles (4.58%/day and 2,191%, respectively), while maximal GR and SR were obtained for large juveniles (0.29 mm/day and 99.17%, respectively). A wide range of sizes was evident at the end of each trial. The WLR of small and large juveniles fit with a negative allometric growth trend. This study highlights the potential production of I. badionotus as early juvenile stages withstand hatchery handling well and exhibit a high SR, reaching commonly released mean sizes (>0.7 g and 25 mm) after almost 3 months (120 days postfertilization).     

Effect of diet on growth and body biochemical composition of juvenile four‐sided sea cucumber Isostichopus badionotus (Selenka, 1867)

The farming of sea cucumber is a growing industry that demands feeds that are tailored to the organism's nutritional needs. Therefore, in this study, the effect of diet composition, with and without additives, on the growth, survival, specific growth rate (SGR) and body biochemical composition of the four‐sided sea cucumber Isostichopus badionotus was evaluated over a period of 3 months. Four diets were used: D1 (Macrocystis sp. and Sargassum sp.), D2 (Macrocystis sp. and Spirulina sp.), D3 (Sargassum sp. and Spirulina sp.) and D4 (Macrocystis sp., Sargassum sp. and Spirulina sp.), and the same diets enriched with 0.22% of Algamac 2000^® (D1H, D2H, D3H and D4H) were also tested. The organisms fed the diets containing Spirulina sp. demonstrated the highest growth rates and significantly greater SGR (% per day) (p < .05), an effect that was enhanced by the food additive (D2 0.67%; D2H 0.78%; D3H 0.76%). Survival and body composition were not affected by diet type. Based on these results, the use of Spirulina sp. combined with supplements rich in PUFA content is recommended in the formulation of diets to promote the growth of I. badionotus juvenile.     

花刺参胚胎和幼体发育的形态观察

为提高花刺参育苗技术,对花刺参自受精卵发育到稚参的形态变化进行了观察研究,详细描述了胚胎发育各个时期的形态特征。通过阴干、流水刺激法对成熟亲参进行人工催产,得到大量的受精卵。在水温27~30℃及盐度33.0~35.0室内水泥池进行花刺参幼体培育。花刺参受精卵经5h发育成囊胚,7h进入旋转囊胚期,9h进入原肠期,31h完成胚胎发育变态为耳状幼体,并经10d的生长发育进入樽形幼体,第20d变态为稚参。由结果可知,花刺参的幼体的健康状况与其水体腔和胃部生长发育状况密切相关,水体腔和胃部发育良好,花刺参的健康状况则佳,有利于幼体的变态与存活。     

Spawning of the Temperate Sea Cucumber,Australostichopus mollis (Levin)

The spawning of sea cucumbers is related to the interaction of environmental cues and reproductive maturity. Groups of Australostichopus mollis were collected every 2 wk during the summer reproductive season from mid‐October to early February. They were observed for spawning in the hatchery during heat‐shock trials conducted 3–5 C above ambient seawater temperature. Lunar periodicity existed with spawning being most prominent in the week following a full moon. In the week prior to a spawning event, there was also a decrease in ambient incoming seawater temperature. More than 75% individuals spawned during most trials in which spawning occurred. In total, 40% of the 270 individuals spawned during the reproductive season. Reliable spawners were females with a yellow gonad color and large numbers of vitellogenic oocytes, and males with large numbers of spermatocytes and an absence of motile spermatozoa. Furthermore, the percentage germinal vesicle breakdown of oocytes exposed to starfish radial nerve extract compared to seawater was greater for the more orange‐colored gonad of nonspawners. Gonad color is useful in determining the likelihood of spawning over a 2‐wk period in the presence of a cue. Sea cucumbers held for short periods in the hatchery during the reproductive season maintain a natural rhythm of spawning that can be monitored using visual indices and augmented using heat shock.     

Preliminary Study of the Optimum Dietary Riboflavin Level in Sea Cucumber,Apostichopus japonicus (Selenka)

A 14‐wk feeding trial was carried out to evaluate the optimum dietary riboflavin (vitamin B₂) level in juvenile sea cucumber, Apostichopus japonicus. A total of 360 sea cucumbers averaging 1.49 ± 0.07 g (mean ± SD) were randomly distributed into 18 rectangular plastic tanks, and each tank was then randomly assigned to one of three replicates of six diets containing 0.29 (B₂0), 4.22 (B₂4), 8.93 (B₂9), 17.9 (B₂18), 56.7 (B₂57), and 577 (B₂577) mg riboflavin/kg diet. At the end of 14 wk of feeding trial, average weight gain (WG) of sea cucumbers fed B₂9, B₂18, B₂57, and B₂577 diets were significantly (P < 0.05) higher than that of animals fed B₂0 diet. WG of sea cucumbers fed B₂18, B₂57, and B₂577 diets were significantly higher than those of animals fed B₂0 and B₂4 diets. Specific growth rate of sea cucumbers fed B₂9, B₂18, B₂57, and B₂577 diets were significantly higher than those of animals fed B₂0 and B₂4 diets. Feed efficiency of sea cucumbers fed B₂9, B₂57, and B₂577 diets were significantly higher than those of animals fed B₂0 and B₂4 diets. Although significant differences were recorded in proximate composition of sea cucumbers fed the experimental diets, no clear trends were observed. The ANOVA test suggested that the optimum dietary riboflavin level in sea cucumber could be 17.9 mg/kg diet but broken‐line analysis of WG indicated a level of 9.73 mg riboflavin/kg diet. Therefore, these results may indicate that the optimum dietary riboflavin level in sea cucumber could be higher than 9.73 mg/kg diet but lower than 17.9 mg/kg diet.     

Effect of Bacteriophages on Vibrio alginolyticus Infection in the Sea Cucumber,Apostichopus japonicus (Selenka)

Vibrio alginolyticus is an important pathogen that causes a variety of diseases in marine animals including the sea cucumber, Apostichopus japonicus. Herein, we describe a two‐phage mixture which may have potential for use as an antibacterial agent to prevent V. alginolyticus infection in the sea cucumber. A Z1210 bacterial isolate was cultured from diseased sea cucumber suffering from skin ulcerations and viscera ejection. The isolate was identified as V. alginolyticus by morphology and sequence similarity analysis. Subsequently, two bacteriophages infecting isolate Z1210 were isolated from the drainpipe of an aquatic market. Morphologically, these two phages were classified as members of Podoviridae (PVA1) and Myoviridae (PVA2) and each phage showed high virulence in an in vitro experiment. Additionally, an experiment conducted in a marine environment showed that a mixture of the two phages increased the survival of sea cucumbers (10 ± 2 g) to 73, 50, and 47% when it was used with a multiplicity of infection of 10, 1, or 0.1, respectively. This result differed markedly from the control without phage (3% survival) while there was no significant difference between the 80 and 47% survival observed for two antibiotic treatments (5 mg/L doxycycline and 10 mg/L kanamycin, respectively).     

Induction of Spawning in the Sea Cucumber Holothuria scabra (Echinodermata: Holothuroidea)

With the advent of sea cucumber aquaculture in the South Pacific region, a reliable method is needed to induce large numbers of animals to spawn in captivity. Broodstock of the sea cucumber Holothuria scabra , collected from Stradbroke Island, Moreton Bay (27°90'N, 153°24'E) Australia, during the reproductive season from October to January, were used in spawning trials. During the 1997–1998 summer between one to five weeks of captivity, 100% of animals were induced to spawn in four trials at dusk on or close to a new or full moon, using nine males and nine females contained in a Reln tank and 30 cm of filtered sea water, using a 3–5 C temperature shock. H. scabra was induced to spawn in small numbers during the 1996–1997 summer despite a marked degree of weight loss, and all animals spawned during 1997–1998 with minimal loss of weight. The difference in the number of spawned eggs between animals of similar size and mean numbers of spawned eggs in consecutive trials decreased the longer animals were held in captivity before spawning. The hatch rate of eggs was reduced significantly for broodstock held for more than one month. Hatch rate and numbers of spawned eggs are important indicators of egg viability of broodstock maintained in captivity for an extended period.     

Preliminary Study of the Optimum Dietary Ascorbic Acid Level in Sea Cucumber,Apostichopus japonicus (Selenka)

A 14‐wk feeding trial was carried out to evaluate the optimum dietary ascorbic acid (AA) level in juvenile sea cucumber, Apostichopus japonicus. Sea cucumbers averaging 1.49 ± 0.07 g (mean ± SD) were randomly distributed into 18 rectangular plastic tanks of 20 L capacity in a recirculating system (20 animals per tank). Six semipurified experimental diets were formulated to contain 0 (l ‐ascorbyl‐2‐monophosphate [AMP]; AMP0), 30 (AMP24), 60 (AMP48), 120 (AMP100), 240 (AMP206), and 1200 (AMP1045) mg AA/kg diet in the form of AMP using casein as the main protein source. Sea cucumbers were fed each of the six experimental diets in triplicate groups. At the end of 14 wk of feeding trial, weight gain (WG), specific growth rate (SGR), and feed efficiency (FE) of sea cucumbers fed AMP100, AMP206, and AMP1045 were significantly (P < 0.05) higher than those of animals fed AMP0, AMP24, and AMP48. However, there were no significant differences in WG, SGR, and FE among sea cucumbers fed AMP100, AMP206, and AMP1045 and among animals fed AMP0, AMP24, and AMP48. Whole‐body vitamin C concentration increased with AA content of the diets. Broken‐line analysis of WG showed an optimum dietary AA level of 105.3 mg AA/kg diet in sea cucumber. These results indicated that the optimum dietary vitamin C level in sea cucumber in the form of AMP could be greater than 100 mg AA/kg diet but less than 105.3 mg AA/kg diet.     

Evaluation of Processing Methods on the Nutritional Quality of Sea Cucumber (Apostichopus japonicus Selenka)

The close relationship between the consumption of sea cucumber and health status stems from the nutritional and functional substances found in sea cucumber that play a key role in the prevention of different diseases. The processing methods have a great effect upon the nutritional and functional substances in sea cucumber. A superior product should not only be abundant in nutritional substances, but also require an easy and cost effective processing method. This study compared the influence of processing methods on the stability of macronutrients and micronutrients present in sea cucumber in order to recommend products that could provide high nutritional quality. The five processes investigated were hot air drying (60°C), vacuum freeze-drying (0.5 cm thickness material, 5–10 Pa vacuum degree, ?85 to ?90°C cold trap temperature, ?25°C material temperature), sun drying, double-distilled water cooking followed by sun drying, and 3.5% sodium chloride solution cooking followed by sun drying. A significant decrease of all the chemical compositions determined was shown in all the sea cucumber products treated by the five processing methods (p < 0.05). Among all the processing methods, hot air drying resulted in the highest nutritional quality of the product. Moreover, hot air drying can be operated easily with low cost.     

海参Apostichopus japonicus(Selenka)育苗新技术--土池生态育苗

刺参（Apostichopus japonicus）室内人工育苗成本高、用药量大、体质差，污染环境，威胁海参种质和食品安全。2005年5～9月，在辽宁省大连海兴食品有限公司5亩海水土池塘中，采用肥水等措施成功育出了海参苗57．1万个头，平均个体重1．47g，产量408kg，苗种体深褐色，体质健壮。     

栉江珧(Atrina pectinata)催产方法及幼虫培养条件

为探究江珧亲贝的最佳催产方法及减少工厂化育苗过程中栉江珧幼虫上浮粘连现象,分别研究了不同催产方法对受精率和胚胎发育的效果,不同培育密度和培育方式对幼虫生长发育的影响。结果显示,阴干4 h后用升温3℃的次氯酸钠中和海水,可诱导亲贝大量排放精卵。并且对卵子受精及胚胎发育影响较小。幼虫培养实验结果显示,幼虫最适培育密度为1 ind/ml,在降低幼虫培育密度的同时,在培育池内安装造浪泵,使培育水体流动起来,能够有效减少幼虫的相互粘连提高幼虫的成活率。     

土池网箱培育仿刺参Apostichopus japonicus(Selenka)幼参的试验

2006年8月～11月,在面积33亩的土池塘中,放置10个用60目筛绢围成的6m×6m网箱,每个网箱中放置115、145、175或200个网吊,每个网吊由6个50cm×50cm的聚乙烯网片串成。每个网箱放入体重5.0mg(20万头/kg)或12.5mg(8万头/kg)的稚仿刺参(Apostichopus japonicus)0.3～0.5kg。经85d的饲养,培育出幼刺参19.39kg,平均每个网箱1.9kg,规格为540～702mg,成活率4.1%～9.6%。文中讨论了土池网箱培育幼刺参的技术关键,强调应在水温8℃～15℃下尽早放养、适时投喂、加大水交换量。     

Assessment of Egg and Larval Quality during Hatchery Production of the Temperate Sea Cucumber,Australostichopus mollis (Levin)

A greater understanding of the causes of variation in egg and larval quality during larval rearing of sea cucumbers will assist in the development of methods to further improve production in hatcheries. For Australostichopus mollis the techniques and methods used in other hatcheries during fertilization resulted in polyspermy occurring in 10–60% of spawned eggs. Despite this, hatch rates were usually greater than 90%. By Day 18 when fed the diatom Chaetoceros muelleri at 2000 cells/mL/day, survival in cultures varied between 35 ± 26% and 57 ± 25%. Of remaining larvae, 10–12% remained in the water column for long periods and did not complete metamorphosis. Furthermore, observation of development in relation to growth and feeding rather than gut content was a better indicator of larval competence. Larvae that were between 700 and 1000 ± 50 μm in length had between four and eight hyaline spheres in the folds of the ciliated band and were in various stages of metamorphosis and settlement. Assessment and comparison of current and previous methods enabled a greater understanding of sources of variation in egg and larval quality, impacts on the production cycle, and suggested improvements.     

Hormonally Induced Spawning, Embryonic Development, and Larval Rearing of the Southern Temperate Banded Morwong, Cheilodactylus spectabilis

Banded morwong (Cheilodactylus spectabilis) are of interest for marine finfish aquaculture in temperate southern Australia. To improve their ovulatory response, adult females were implanted during the autumn spawning season with slow‐release pellets containing 0–400 μg luteinizing‐hormone‐releasing hormone analogue (LHRHa)/kg body weight within 24 h of capture from the wild. Compared to the sham control group, animals treated with LHRHa produced significantly more eggs on each day after implantation for the following 7 d (91 ± 39 and 290 ± 38 mL) and a higher proportion ovulated (8/12 and 27/27). Of fish treated with LHRHa, 93% ovulated 2 d after implantation and 79% ovulated three times at 2‐d intervals, whereas control animals showed no cyclicity of ovulation and few ovulated more than once. Egg production was highest at the first ovulation after LHRHa treatment and declined at subsequent ovulations. In a second experiment investigating the range 100–400 μg LHRHa, there was no effect of dose rate on ovulation parameters, which additionally examined implantation either immediately after capture or after a 5‐d delay. Compared to immediate implantation, a delay resulted in a lower proportion of animals that could be stripped after implantation (100 and 50%, respectively) and the volume of eggs was lower (135 ± 15 and 107 ± 10 mL). The egg quality was poor following delayed implantation, resulting in no fertilization after artificial insemination compared with immediate implantation in which fertilization and hatch rates were higher for eggs collected on Day 2 after implantation (79 ± 8% and 58 ± 9%) than on Day 4 (23 ± 7% and 15 ± 6%). Thus, it is important to implant animals as soon as possible after capture to ensure optimum egg quality. Good‐quality eggs were buoyant and spherical and had a diameter of 1050 ± 25 μm with a single pigmented oil droplet of 190 ± 9 μm. When a separate large batch of eggs collected 2 d after implantation with 100 μg LHRHa was inseminated and cultured at 18 C, larvae hatched after 63 ± 2 h at a standard length of 2.6 ± 0.4 mm. Newly hatched larvae were buoyant and transparent with only a few melanophores, eyes were nonpigmented and jaws were nonfunctional. By the fourth day, jaws were functional and eyes were fully pigmented. Utilization of the endogenous yolk and oil was completed by Day 6, and swimming commenced with exogenous feeding. Larvae, initially fed lipid‐enriched rotifers followed by Artemia, reached 8.9 ± 0.7 mm length on Day 55, after which they metamorphosed to the postlarval paperfish stage of development, 22 ± 0.9 mm on Day 100, and 43 ± 1.0 mm at 6 mo of age. The results show that treatment of wild‐caught females with slow‐release pellets containing LHRHa is effective for the production of eggs for hatchery rearing.     

pH胁迫对刺参存活、生长及抗氧化酶活性的影响

本研究比较分析了在对照组(pH为8.4)、低pH胁迫组(pH为6.8、7.0、7.2、7.4、7.6和7.8)和高pH胁迫组(pH为8.6、8.8、9.0、9.2、9.4和9.6)的养殖水环境下,胁迫36 d对刺参(Apostichopus japonicus Selenka)存活、生长及抗氧化酶活性的影响。结果显示,不同pH对刺参存活、生长及抗氧化酶活性有显著影响。在pH 7.4~9.0范围内,刺参存活率为100%,随着pH胁迫强度和胁迫时间的增加,刺参存活率逐渐降低,当pH为6.8、7.0和9.6时,自第3天起,刺参处于过度应激状态,继而有死亡个体出现,至30 d时刺参死亡率为100%。不同pH显著影响刺参生长,刺参特定生长率随pH胁迫程度增加呈下降趋势,当pH为9.0时,刺参出现负增长。各pH胁迫组刺参超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均高于对照组,且随pH胁迫程度的增加呈先升高后下降的变化趋势。在低pH组中,以pH=7.4时刺参SOD和CAT活性最高,分别达到(74.92±2.24)U/ml和(14.99±2.38)U/ml,显著高于对照组;而在高pH组中,SOD和CAT活性分别以pH 8.8和9.0时最高,分别达到(72.90±1.10)U/ml和(15.68±0.89)U/ml,显著高于对照组。结果表明,pH在7.4~9.0范围内是刺参存活与生长的适宜水环境,过高或过低均会引起刺参不同程度的应激反应,进而导致刺参的死亡。     

在土池网箱中促进仿刺参(Apostichopus japonicus)繁殖、变态和附着的研究

2007年5～8月在大连瓦房店市交流岛乡一口面积2.36 hm2的仿刺参(Apostichopus japonicus)养殖池中放置10个200目5m×5m×2.0m和1个长2.0m×宽1.5m×高1.0m的网箱,采用3种方法促进仿刺参繁殖和附着.第一种是让其在室内产卵后发育到耳状幼体初期时,放到室外的大网箱中正常培育.第二种是在室外的小网箱中催熟、产卵,发育至耳状幼体初期放到大网箱中培育.第三种方法是把种参放在大网箱中自然促熟、产卵和培育.经40d的试验,共催产亲参126头,获受精卵1.98亿粒,孵出耳状幼体1.03亿,孵化率52.02%,培育出稚参16.91万头.室内水槽中催产、受精和孵化的效果与室外网箱差异不显著,但室外网箱催产、受精和孵化操作简单,易于大面积推广和生产绿色稚参.     

Maturation and Spawning of Blue Shrimp Penaeus stylirostris (Stimpson) under Hypersaline Conditions

Maturation and spawning of blue shrimp Penaeus stylirostris were obtained in hypersaline and turbid water. Results indicate that number of spawnings per female and percentage of viable spawnings are similar to those reported under "standard" conditions by other investigators. However, the number of nauplii produced was 50 to 75% less. A significant correlation was observed between reproductive activity and lunar cycles, showing peak activity at three to four days following new moon. Additionally, working with records of individual females, the number of spawnings per female was found to be extremely variable, with intervals between consecutive spawnings non-uniform. Instead, they tended to group in pairs with less than six days between spawnings, followed by a variable period of time (usually more than 12 days) before the paired spawnings were repeated.     

Effects of differently processed diets on growth,immunity and water quality of the sea cucumber,Apostichopus japonicus (Selenka, 1867)

The type of formulated diet used in aquaculture systems affects the feed efficiency and water quality. In this study, the water quality, growth performance and immunity of the sea cucumber, Apostichopus japonicus (Selenka, 1867), fed diets produced using four different processing methods (extruded pellet diet, cold‐bonded pellet diet, flake diet and mash diet) were quantified for 60 days to identify the optimal feed type for culturing of this species. Sea cucumbers grew faster, the feed conversion ratio was much lower, and immunity indicators were higher when fed the extruded pellet diet compared to the other diets. Sea cucumbers fed the extruded pellet diet had the highest specific growth rate (0.96), whereas A. japonicus fed the cold‐bonded pellet diet had the lowest specific growth rate (0.51). The lysozyme activity of sea cucumbers fed the extruded pellet diet was higher (57.52) than that of A. japonicus fed the cold‐bonded pellet diet (39.22), flake diet (37.32) and mash diet (32.68). When animals were fed the mash diet, the ammonia–nitrogen, nitrite–nitrogen and phosphate productions were higher than in animals fed the other diets. These results indicate that the extruded pellet diet is the optimum feed type for use in the culture of A. japonicus.