• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.142-147
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• 2018

This study was conducted to investigate the effects of practical diets containing different seaweed powders on the growth and body composition of juvenile sea cucumber Apostichopus japonicus. Six experimental diets were formulated to contain 40% of the following seaweed powders: Sargassum thunbergii (ST), Undaria pinnatifida (UP), Ascophyllum nodosum (AN), Hizikia fusiformis (HF), fermented Laminaria japonica (FLJ), and fermented Hizikia fusiformis (FHF). Sea cucumbers (30 per tank; initial mean weight $0.4{\pm}0.01g$) in three replicates of six groups were fed one of the six experimental diets for 15 weeks. Survival in all groups was 83-93%, with no significant differences among the experimental groups. The specific growth rates of the sea cucumbers fed the ST and UP diets were significantly higher than those of sea cucumbers fed the HF, FLJ, and FHF diets, but did not significantly differ from those of sea cucumbers fed the AN diet. The results of this study suggest that S. thunbergii, U. pinnatifida, and A. nodosum could be useful sources of seaweed powder for practical diets of juvenile sea cucumber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.474-485
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• 2016

This study compared the fatty acid composition of wild and cultured specimens of the sea cucumber Apostichopus japonicus. We extracted total lipids from the specimens and determined their fatty acid compositions through capillary gas chromatography, resulting in the identification of 53 fatty acids. We found that wild sea cucumbers were rich in palmitoleic (C16:1n-7) and eicosapentaenoic acid (C20:5n-3), whereas cultured specimens were rich in eicosenoic (C20:1n-9) and arachidonic acid (C20:4n-6). In both types of sea cucumbers, the highest percentage of polyunsaturated fatty acids (PUFA) consisted of polar lipids (PL), followed by total lipids (TL) and neutral lipids (NL). Cultured sea cucumbers contained a higher percentage of total lipids (TL) than wild sea cucumbers did, whereas there was no significant difference between the two groups in the percentages of neutral (NL) and polar lipids (PL).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.168-175
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• 2016

We conducted a 90-day feeding experiment to evaluate the growth and energy budget of the sea cucumber Apostichopus japonicus. Sea cucumbers with a mean initial wet body weight of 3.03±0.06 g were fed one of the following three diets: an eel fecal solid diet, rainbow trout fecal solid diet, or a commercial diet at a water temperature of 17±1℃ and salinity of 32±1 psu. The results suggested that the diets affected the final body weight, specific growth rate (SGR), food ingestion, feces production ratio, and hence the growth and energy budget of the sea cucumbers. Sea cucumbers fed the eel and rainbow trout fecal solid diets showed poorer energy absorption, assimilation, and growth than those fed the commercial diet. The sea cucumbers fed the commercial diet had a significantly higher SGR and proportion of energy used for growth than those fed the other two diets. Sea cucumbers fed the rainbow trout fecal solid diet showed a comparatively higher ingestion rate and feces production ratio than those fed the commercial diet. The eel and rainbow trout fecal solid diets, therefore, were not suitable for sea cucumbers in intensive cultivation. Our findings will facilitate further development of more appropriate diets for culture of sea cucumber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.337-342
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• 2016

Sea cucumbers have been an important part of human diets throughout history; demand is increasing every year, making the species a target for coastal resource development. New harvesting technologies have been developed in response to demand, including nursery production and insemination aquaculture, but such methods produce relatively few individuals and productivity per unit area is very small. For example, captures are prohibited during July and August due to the breeding season, and sea cucumbers aestivate during the hot season and hibernate during the cold season, all factors that limit natural-environment production in Korea. Problems with slow growth of sea cucumbers have been encountered in previous rearing experiments. To assess the importance of feeding ecology on sea cucumber growth, we conducted pond-bottom and lantern-net culture experiments. Results showed that sea cucumbers in bottom cultures grew from 3.06 to 102.59 g, but those in lantern cultures only grew from 25.60 to 28.03 g.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.49-59
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• 2017

The objective of this study was to investigate the growth rate and the optimal stocking density of sea cucumbers. Grow-out was studied in situ by conducting a follow-up survey using visible implant elastomer (VIE) tags. The rearing systems were made of polypropylene pipe for the frames and netting. The experiment ran for 70 days near Yeosu, Korea in the water depth of about 7 m. A total of 576 sea cucumbers which have three groups of body sizes (small: 5.15, medium: 12.34 and large: 23.26 g) were used. The five groups of stocking densities (150, 300, 450, 600 and $850g/m^2$) in rearing system for sea cucumber were considered. Sea cucumbers were fed a mixed diet (mud, mineral, fish meal, etc.). The feed was supplied to 10% of their body wet weight once every 7 days. The survival rate (73%) of sea cucumber in $850g/m^2$ was lower than those of other density groups ($150g/m^2$: 89%, $300g/m^2$: 84%, $450g/m^2$: 78% and $600g/m^2$: 86%). The survival rate of medium size group was higher than those of small and large groups regardless of the density (P<0.05). Most of density groups have no significant difference except for $850g/m^2$ (P>0.05). The growth rate of small size group ($0.63%day^{-1}$) was higher than those of medium ($0.38%day^{-1}$) and large ($0.34%day^{-1}$) group regardless of the density (P<0.05). The threshold water temperature was $11.0^{\circ}C$ for sea cucumber growth in winter season.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1407-1416
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• 2016

This study was conducted to investigated the effects of stocking density on growth and survival of sea cucumber, Apostichopus japonicus in the indoor multiple tank for 12 weeks. There were six treatments(stocking densities) in this experiment, i.e. 1, 2, 3, 4, 5 and 10 individuals per 10 L plastic aquarium($W41{\times}H24{\times}D11cm$, represented as D1, D2, D3, D4, D5 and D10, respectively). Each treatment had ten replicates. The results showed growth variation of sea cucumber, Apostichopus japonicus decreased with the increase of stocking densities. After the end of the experiment, no significant differences(P>0.05) between D1~D5 treatment group whereas significant differences(P<0.05) between D1 and D10 treatment group. Survival rate showed D1~D10 were 90%, 90%, 100%, 95%, 94% and 72%, respectively. Especially, significant differences(P>0.05) between D1~D5 and D10 treatment group. The results indicated optimum of stocking density for sea cucumber, Apostichopus japonicus within five individuals per 10 L plastic aquarium($0.05individuals/m^2$).

• Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.90-100
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• 2022

Cardiovascular diseases (CVDs) have posed serious public health problems, accounting for nearly 30% of mortality worldwide and their incidence is still increasing. Therefore, new treatment resources are necessary to prevent or manage the ever-increasing population of patients with CVDs. Sea cucumber is well known for its medical and health benefit effects, but it is not well known what/how effect it has on vascular disease. In the present study, we examined the protect effect of sea cucumber, Apostichopus japonicus 80% ethanol extract (AJE) on zebrafish embryo with the stimulation of free fatty acid, palmitate (PA). In vivo study showed that AJE can attenuate PA-induced toxicity through relieving the rapid heartbeat, increasing the survival rate and reducing the malformation in both wild type and Tg (fli1a:eGFP) transgenic zebrafish lines. Additionally, compare with PA treated embryos, the yolk sac area, body length, axial vascular segment (AVS) and intersegmental vessel (ISV) of the co-treatment group of AJE and PA were comparable to the control group. Moreover, AJE lowered the expression of inducible nitric oxide synthase (iNOS), nitric oxide (NO) and inflammation-related genes induced by PA, and inhibited PA-induced vascular development disorders. Our data preliminarily verify that AJE could be a candidate resource for the prevention or therapy of CVDs.

• Development and Reproduction
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• v.27 no.2
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• pp.91-99
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• 2023

The sea cucumber, Apostichopus japonicus, is one of the most valuable aquatic species. The color of body wall and appearance are important for the value of sea cucumbers. To examine expression pattern of long-chain acyl-coenzyme A dehydrogenase (LCAD), nuclear distribution C-containing protein 3 (NUDCD3), and receptor tyrosine kinase Tie-1 (TIE1), previously reported as differently expressed genes during the pigmentation of sea cucumber, we analyzed the temporal profiles of LCAD, NUDCD3, and TIE1 mRNAs in LED-exposed and light-shielded A. japonicus. Real-time quantitative PCR revealed that the LCAD, NUDCD3, and TIE1 mRNAs from the juveniles at 40-60 days post-fertilization (dpf) exhibited increasing patterns as compared to those of an early developmental larva (6-dpf). At 60-dpf juveniles, the LCAD and TIE1 mRNA levels of LED-exposed individuals were higher than those of light-shielded ones, whereas at 40-dpf and 50-dpf juveniles, the NUDCD3 mRNA expression was higher in the light-shielded condition (p<0.05). In the pigmented juveniles (90-dpf), the LCAD and TIE1 mRNA levels tended to show higher levels in red individuals than those in green ones, but there was a conversely higher level of NUDCD3 mRNA in green larva. In situ examination of LCAD and NUDCD3 mRNAs in light-shielded 6-dpf larva revealed that both genes are mainly expressed in the internal organs compared to the body surface. Together, these results may provide insights into the differential gene expression of LCAD, NUDCD3, and TIE1 during pigmentation process of the sea cucumber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.443-448
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• 2022

Two long-term feeding trials were conducted to compare the effects on survival and growth of juvenile sea cucumber Apostichopus japonicus of experimental diets containing corn distillers dried grains with solubles, Squid Sepioteuthis sepioidea liver meal, and brown fish meal with a commercial die. In both first and second trials, two experimental diets and one commercial diet were assessed. After a 45-week feeding period in trial 1, survival did not differ significantly among groups. The final mean weight of sea cucumbers fed either experimental diet was significantly higher than that of sea cucumbers fed the commercial diet. After a 15-week feeding period in trial 2, survival and final mean weight of sea cucumbers fed either experimental practical diets was significantly higher than that of sea cucumbers fed the commercial diet. It was concluded that the experimental diets formulations can be used as a practical diet, and inclusion of corn distillers dried grains with solubles, squid liver meal, and brown fish meal can improve the growth of juvenile sea cucumbers.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.2
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• pp.202-213
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• 2014

The sea cucumber, Apostichopus japonicus, is becoming an important aquaculture species in China, Japan and Korea. The purpose of this study is to evaluate the biological performance of a tubular type of subsurface cage for sea cucumber grow-out by in-situ tests. The cage structure was constructed of PP (polypropylene) frames and PP tubes (${\phi}130mm{\times}24pieces$). A set of tests were conducted at a depth of 15 m near Seosaeng, Ulsan, Korea for 295 days (23 July, 2012 to 13 May, 2013). A total of 155 sea cucumbers were used and fed a mixed diet containing mud, mineral, wheat, fish meal, etc (3% of their body weight). At the end of the experiments, sea cucumber showed a higher survival rate in feed shelter (77.14%) rather than no feed shelter (64.71%). The specific growth rate (SGR) of sea cucumbers in feed condition (0.04% $day^{-1}$) was higher than that of no feed culture animals (-0.49% $day^{-1}$) during total experimental periods. The result was able to find a no significance difference in survival rate but a significance difference in SGR under feed and no feed treatments.