• Journal of Aquaculture
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• v.11 no.4
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• pp.437-447
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• 1998

In mass production of larval rockfish, Sebastes schlegeli, high mortality had been observed frequently. This may be the consequence of the low nutritional quality of the live feeds used. This experiment was designed to find out a suitable diet for the mass production of rockfish larvae. Three kinds of live feeds were tested ; plutei of sea urchin (Hemicentrotus pulcherrimus), L-type rotifers (Brachionus plicatiilis) and Artemia naupii. The latter two were enriched with ${\omega}$-yeast, Spirulina platensis and Super Selco before feeding to rockfish larvae. The sea urchin plutei caused to poor survival and growth rates for larval rockfish, and therefore, they were not seemed as proper feed for rockfish larvae. Enrichments of rotifers and Artemia nauplii with ${\omega}$-yeast, Spirulina platensis, or Super Selco improved survival and growth rate. But, rotifers enriched with Super Selco resulted in better rockfish larvae survival than those enriched with ${\omega}$-yeast. A sudden increase of mortality occurred around 11 days after birth. In this critical period, a shift feed such as Artemia nauplii had been supplemented with rotifers. After this critical transition period, the moratality gradually decreased by feeding Artemia nauplii enriched with PUFA. Feeding of mixed feed with rotifers and Artemia nauplii resulted in better larval survival and growth than those of each live food alone.

• Journal of Aquaculture
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• v.19 no.2
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• pp.109-118
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• 2006

The recent decrease in wild stocks of seahorse, Hippocampus coronatus, has prompted the production of the species in captivity. We here present data on the body color changes of the species according to culture conditions. This investigation examined relationship between adult body size and clutch and growth in 60 days after parturition and survival of juveniles with four fed enriched Artemia nauplii, copepod nauplii and copepod adult. Seahorse adults ($77.77{\pm}9.84mm$, n=12) collected from Kamak Bay and Yeoja Bay from August 2003 to November 2004 gave a parturition of $6\sim75$ juveniles (Mean, 39 juveniles/male/time) for 14 times. A day old seahorses were $14.48{\pm}1.38mm$ (n=15) in standard length (SL) with 14 dorsal fin rays, 12 pectoral fin rays and 4 anal fin rays. Sixty-day old seahorses were $24.65{\pm}0.83mm$ (n=4) in SL. Growth rate of seahorses was 0.18 mm/day at 24 in 60 days after parturition. When offered Artemia nauplii and copepod nauplii, 5 day old sea-horses preferred copepod nauplii to Aremia nauplii with a maximum predation rate of 31 copepod nauplii/sea-horse/h. However 30-day old seahorses preferred selected Artemia nauplii with a maximum predation rate of 14 Artemia nauplii/seahorse/h. Survival was highest (49%) when offered copepod nauplii together with enriched Artemia nauplii.

• Journal of Aquaculture
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• v.22 no.1
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• pp.68-73
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• 2009

Yeast has been widely used as a food organism for mass culture of rotifer and also considered as a partial substitute food for microalga in shellfish culture. But the dietary value of yeast is poorer than that of microalga due to its low nutrition and thick cell wall. This study was carried out to find a nutritious yeast species as a food organism and to investigate the nutritional value of manipulated yeast for shellfish. First of all, three species of yeast (Saccharomyces cerevisiae, Candida utilis, Kluyveromyces fragilis) and their manipulated yeast were tested on the survival (%) and growth of Artemia nauplii and Mytilus edulis larvae, which were representative filter feeding animal and easy to control. The survival (%) and growth of Artemia nauplii fed C. utilis were higher than those fed S. cerevisiae or K. fragilis. The growth of Artemia nauplii and M. edulis larvae, which were fed manipulated yeast was higher than that fed non-manipulated one. The manipulated yeast with higher removal rate of cell wall showed better dietary value for Artemia nauplii and M. edulis larvae. M. edulis larvae fed mixed-diet with Isochrysis galbana (50%) and manipulated C. utilis (50%) showed significantly higher growth than those fed single-diet with I. galbana. It means that manipulated C. utilis can substitute I. galbana at least 50% for M. edulis larvae.

• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.201-206
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• 2005

Microalgae are widely used for mass culture of the rotifer Brachionus plicatilis in aquaculture. Since the nutritional value of the rotifer is closely related to its food, the nutritional value of its food should be known in detail. Chlorella ellipsoidea and Nannochloris oculata are re­presentative food organisms for rotifers that are easily cultured. Therefore, the nutritional values of these micro algae were examined for ultrasmall, small, and large rotifers and Artemia nauplii. Chlorella ellipsoidea contained seven times more total fatty acids than N. oculata. The three types of rotifer fed N. oculata contained more amino acids than those fed C. ellipsoidea. However, the total fatty acids of the rotifers fed each microalga species differed according to the type of rotifer. Newly hatched Artemia nauplii contained more protein and had a higher dry weight than those fed microalgae for 6 h. As with the rotifers, the Artemia nauplii fed N. oculata contained more protein and amino acids than those fed C. ellipsoidea, while the reverse was true for the total fatty acid content. Our results suggest that N. oculata is a good supply of protein, while C. ellipsoidea is a good source of lipids as food organisms for rotifers and Artemia nauplii in aquaculture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.339-344
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• 2011

We investigated the effects of enrichment with oil or bacteria on the fatty acid composition of rotifers and Artemia as live prey. One enrichment(oil source) was mainly composed of squid Todarodes pacificus liver oil; the other(photosynthetic-bacterial source) was primarily made up of Schizochytrium sp. The enrichments were intended to enhance the nutritional value of the live prey, such as their EPA, DHA and n-3 HUFA contents. The lipid content as EPA and DHA of rotifers was higher when enriched with the oil source rather than the photosynthetic-bacterial source. The DHA content of Artemia nauplii after enrichment differed significantly, depending on the type of enrichment used(P<0.05). When the Artemia nauplii were enriched with the oil source, the DHA content was increased to 16.8%, whereas it increased only to 1.1% when enriched with the photosynthetic-bacterial source. These results indicate that selection of the enrichment is important for Artemia nauplii but not for rotifers.

• Journal of Aquaculture
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• v.13 no.3
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• pp.197-206
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• 2000

At the Poryoung coast, the spawning season of the mullet, Chelon lauvergnii lasts from May to June. A combination of rotifer, Rotifer nauplii and synthetic feed supported significantly (P < 0.05) better survival and growth of 1-day old mullet larvae during 70-day rearing experiment than the other feeds consisting of rotifer or rotifer + Artemia nauplii. Significantly higher growth and survival were also observed, when the larvae were fed on rotifer, that were harvested from culture enriched with masimaTR, or Artemia nauplii from culture enriched with cuttlefish liver oil, At the feeding density of 97-98 individuals /200 l, the mullet larvae displayed maximum growth and survival in aquarium each with 100 larvae /200 l.

• Animal cells and systems
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• v.8 no.4
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• pp.313-317
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• 2004

A study was conducted to determine growth and survival rates of snakehead (Channa striata) larvae. Live foods such as Artemia salina nauplii, Moina micrura and bloodworm and artificial diet were given to larvae from 1-15 days after hatching as the 1st phase and from 15-30 days as the 2nd phase. In the 1st phase, the growth and survival rates of larvae fed with Artemia nauplii were significantly different from larvae fed with Moina (p < 0.05) with values of 28.5 mg, 49% and 26.7 mg, 31%, respectively. Meanwhile, all larvae fed with bloodworm (Chironomus sp.) or artificial diet (49% protein) died within 10 days of experiment. For the 2nd phase, growth of the fry fed with Artemia or Moina differed significantly from that fed with bloodworm or pellet (200.1, 187.7, 109.6 and 8.2 mg, respectively). Specific growth rate (SGR) of larvae fed with Moina was higher than that of larvae fed with Artemia (17.9 and 17.4% day$^{-1}$, respectively) in the 1st phase. In the 2nd phase, SGRs of larvae fed with Artemia (12.7% day$^{-1}$) or Moina (11.5% day$^{-1}$) were significantly higher than those of larvae fed with bloodworm (8.3% day$^{-1}$) or dry diet (6.1% day$^{-1}$). Generally, Artemia and Moina were suitable food for snakehead larvae during the first month of their life, and artificial diet was much less acceptable and resulted in poor growth and survival.

• Journal of Aquaculture
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• v.17 no.3
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• pp.221-227
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• 2004

In the present study, we investigated the effects of food and salinity on growth and survival of river puffer, Takifugu obscurus offsprings in indoor land-based tank during the early development. In the food experiment, the river puffer larvae (TL 8.7$\pm$0.1 mm, BW 20.0$\pm$3.2 mg) were fed with tubificid, Limnodrilus gotoi, water flea, Daphnia carinata, mysid, Neomysis awatschensis, Manila clam, Ruditapes philippinarum and artificial food together Artemia nauplii for 30 days, and the growth and the survival of larvae were investigated. In the salinity experiment, the river puffer larvae and juvenile at three stages (Stage I: TL 5.8$\pm$0.4 mm; Stage II: TL 12.0$\pm$0.2 mm, Stage III： TL 44.5$\pm$0.7 mm) were supplied with Artemia nauplii, water flea and/or artificial food and were reared in 0, 10, 20 and 30 psu at respective stages. The results shows that the growth rates of larvae feeding with artificial food and tubificid together Artemia nauplii were higher than those of larvae in other groups, but the survival rates of larvae feeding with water flea and mysid together Artemia nauplii were higher than those of larvae in other groups. In salinity, the results shows that the growth and survival rates of offsprings were significantly higher in 10∼20 psu than those in 0 and 30 psu at Stage I and n. At Stage III, the growth and the survival rates were the highest in 20 psu, but the lowest in 0 psu. However, it should be noted that the rates in 0 and 30 psu were significantly enhanced at Stage III in comparison with those at Stage I and II. Therefore, it is concluded that river puffer, T. obscurus is euryhaline marine species, which can normally grow and live at salinities from 0 to 30 psu, and that a combinative supplement with Artemia nauplii and water flea, D. carinata may confer an advantage on growth and survival of the river puffer offsprings in indoor land-based tank.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.275-280
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• 2022

Suspended solids play an important role in the growth and survival of aquatic organisms. The marine zooplankton species tested in this study were Tigriopus west (Copepoda) and Haustorioides koreanus (Amphipoda) sampled from the intertidal zone, including Artemia nauplii(Branchiopoda) hatched from cysts. The study design included six concentrations (0, 50, 100, 250, 500, and 1,000mg L^-1) of the suspended test particles assayed in triplicate. Experimental cultures in 500 mL-round polycarbonate bottles were subsampled after 96 h to count dead zooplankton. The culture bottles were agitated at 4 RPM on a rotating wheel at 23℃ and 30 PSU. The survival rates of Artemia nauplii and T. west were not affected by suspended solid concentrations higher than 50.0 mg L^-1, whereas the survival rate of H. koreanus decreased with increasing concentrations (p<0.05). In conclusion, H. koreanus and T. west, which were continuously exposed to suspended solid concentrations higher than 50.0 mg L^-1, were affected by low-intensity ecological stress. However, in the case of H. koreanus, a concentration of 50.0 mg L^-1 may be considered to be the limit of tolerance to suspended solids, suggesting that the number of individuals who eventually die will increase if continuously exposed.

• Journal of Aquaculture
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• v.11 no.3
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• pp.303-310
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• 1998

The growth and survival rate of larvae and juveniles from female rockfish (Sebastes schlegeli) broodstock in vitellogenesis by injection of 3,5,3'-triiodo-L-thyronine $T_3$ with a dose of 20 mg/kg fish wt. were examined for 30 days and compared with sham-control fish injected dime-thyl sulfoxide and control fish. Larvae were fed with rotifers for first 5 days after parturition, rotifers and Artemia nauplii for next 10 days. And then, they were fed with Artemia nauplii and commercial diet. Growth of larvae and juveniles from maternal $T_3$injection was significantly faster than that of two controls, nevertheless, the condition factor was lower than that of controls. The whole body proximate analyses indicated that there were significant effects of $T_3$ injection on protein and lipid, but no significant on moisture and ash contents. Survival rate of the fish from maternal $T_3$injection was significantly higher than that of fish from the two controls. These results indicate that thyroid hormone supplements appear to confer a distinct advantage to larval and juvenile rockfish in early, fragile development stage.