• 한국수산과학회지
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• 제53권6호
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• pp.900-908
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• 2020

This study was conducted to partially replace fish meal with black soldier fly (BSF) larvae or mealworm (MW) larvae in the diet for Pacific white shrimp Litopenaeus vannamei. A tuna by-product meal (27%) was used as the protein source in a control (Con) diet, which was replaced with 20%, 40%, or 60% BSF (designated as BSF20, BSF40, and BSF60, respectively), or MW (MW20, MW40, and MW60, respectively). The shrimp (average body weight, 0.09 g) were randomly stocked in 28 acrylic tanks and quadruplicate groups were fed one of the experimental diets six times daily. After 57 days of the feeding trial, growth and feed efficiency were significantly higher in shrimp that were fed the BSF40 and BSF60 diets than those in shrimp fed the Con diet. Phenoloxidase, superoxide dismutase, glutathione peroxidase and gene expression of crustin were significantly higher in shrimp fed BSF or MW diets than those in shrimp fed the Con diet. The results indicate that BSF or MW could be used as a fish meal replacement or as a functional protein source in diets and can help improve the growth, feed utilization, innate immunity and antioxidant capacity of Pacific white shrimp.

• 한국어병학회지
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• 제14권2호
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• pp.91-95
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• 2001

1999년 10월에서 11월 사이에 남해안 일대의 홍민어 종묘 생산장에서 20~30열령의 치어가 척추만곡 및 이상유영을 하며 대량 폐사하였다. 병어는 특이 외부 증상이 없었고, 높은 누적폐사량이 바이러스 질병으로 의심되어, 조직학적 및 분자생물학적인 검사를 행하여 폐사원인을 확인하였다. 폐사개체의 조직을 H-E 염색하여 관찰한 결과 뇌와 안구의 신경세포에서 공포와 괴사가 관찰되었고, 전자현미경 관찰에서는 안구와 뇌에서 바이러스 입자가 관찰되었다. RT-PCR 결과에서는 ${\fallingdotseq}426$ bp의 DNA 단편을 확인할 수 있었다. 이러한 결과로 홍민어에서 발생한 대량폐사는 바이러스성 신경괴사증(VNN)으로 진단되었다.

• 한국양식학회지
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• 제11권3호
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• pp.303-310
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• 1998

난황형성 단계에 있는 암컷 어미에게 갑상선 호르몬인 3,5,3'-triiodo-L-thyronine ($T_3$)를 20 mg $T_3$/kg 체중으로 주사하여 출산된 조피볼락 자어를 대조구인 sham구 및 control구 자어와 함께 30일간 사육하면서 성장과 생존율을 비교하였다. 자어에게는 출산후 5일째까지 rotifer를 공급하였고, 6~15일까지 rotifer와 Artemia nauplii를, 이후 30일까지 Artemia nauplii와 넙치용 배합사료를 혼합공급하였다. 출산후 자어의 성장은 대조구들에 비해 $T_3$구에서 유의하게 빨랐으며, 생존율 역시 T하(3)구가 대조구들 보다 유의하게 높았다. 실험종료시 치어의 비만도는 $T_3$구가 control구에 비해 다소 낮았고, sham구에 비해서는 유의하게 낮았다. 이상의 결과, 조피볼락에 대한 $T_3$의 모체주사는 모체에서 유래된 외인성$T_3$가 초기 출산자어의 생리활성을 증진시켜, 자치어의 성장과 생존율 향상에 도움을 줄 수 있는 것으로 평가되었다.

• 한국수산과학회지
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• 제37권1호
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• pp.7-12
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• 2004

This study investigated the possibility of salinity acclimation of freshwater rotifers (Brachionus calyciflorus) as live food for sweetfish (Plecoglossus altivelis) larvae, and also examined the optimal salinity for the growth of sweetfish. Freshwater rotifers cultured in 0 and 4 PSU and seawater rotifers (B. rotundiformis) cultured in 33 PSU were supplied to the larvae with four kinds of enrichment material (condensed freshwater Chlorella, $\omega-yeast,$ baker's yeast, Super Selco) and larval growth at 4 PSU was examined. Growth of the freshwater rotifers positively increased from 0 PSU to 6 PSU, but decreased when over 8 PSU was reached. Growth and survival of the sweet fish larvae reared in 0 PSU were significantly lower than those reared in either 4 PSU or 33 PSU. This indicated that the freshwater rotifers (B. calyciflorus) could be used as live food for sweetfish larvae reared in 4 PSU. The body weight of sweetfish larvae fed on freshwater rotifers enriched with Super Selco was the highest at 0.163 mg, but there was no significant difference in survival and body length of the fish fed with the other enrichment materials. The content of n-3 HUFA of the sweetfish larvae fed on the freshwater rotifers enriched with Super Selco and the condensed freshwater Chlorella was higher than that enriched with $\omega-yeast$ and baker's yeast. These results indicated that B. calyciflorus cultured with the condensed freshwater Chlorella could be used for the sweetfish larvae without enrichment, and the most efficient enrichment material for B. calyciflorus is Super Selco.

• 한국수산과학회지
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• 제53권1호
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• pp.74-82
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• 2020

Dragonet fish (Callionymidae), living in benthic upper 900 m of all subtropical, tropical and temperate oceans, comprises 200 species in 20 genera worldwide, of which 18 species in 6 genera occur in Korea. Although dragonet fish plays an important role in linking between top predators and lower trophic levels, there are only few studies about their early life history. Herein, we present molecular and morphological data on larvae and juveniles of Bathycallionymus kaianus (Günther, 1880) collected from the Korean waters. During 2016 to 2018, one preflexion larvae [2.69 in total length (TL)], three flexion larvae (3.65 and 4.77 mm TL), six postflexion larvae (6.07 and 7.94 mm TL), and three juveniles (10.81 and 12.26 mm TL) were collected in the East Sea, Korea Strait, and Jeju Island using Bongo net. Of them, 13 individuals were identified through molecular markers (COI or 16S rRNA) and morphologically described. The larvae of B. kaianus are well distinguished from other species of Callionymidae in melanophore distribution, body shape and development of preopercular spine. It was very similar to larvae of two Repomucenus species, R. valenciennei and R. virgis, but was clearly distinguished in melanophore distribution, preopercular spine development, and head shape.

• Parasites, Hosts and Diseases
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• 제53권3호
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• pp.349-353
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• 2015

Anisakis simplex sensu stricto (s.s.), Anisakis pegreffii, Anisakis berlandi (=A. simplex sp. C), and Anisakis typica are the 4 major species of Anisakis type I larvae. In the Republic of Korea (Korea), A. pegreffii, A. berlandi, and A. typica larvae in fish hosts has seldom been documented. In this study, molecular analysis was performed on Anisakis larvae from the sea eels (Astroconger myriaster), the major source of human anisakiasis in Korea, collected from Tongyeong City, a southern coastal area of Korea. All 20 sea eels examined were infected with Anisakis type I larvae (160 larvae; 8 per fish). Their species were analyzed using PCR-RFLP patterns and nucleotide sequences of internal transcribed spacers (ITS1, 5.8 subunit gene, and ITS2) and mitochondrial cytochrome c oxidase 2 (cox2). Most (86.8%; 112/129) of the Anisakis type I larvae were A. pegreffii, and 7.8% (10/129) were A. typica. The remaining 5.4% (7/129) was not identified. Thus, A. pegreffii is the major species of anisakid larvae in sea eels of the southern coast of Korea.

• 한국수산과학회지
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• 제50권3호
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• pp.287-295
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• 2017

Egg development and morphological change of larvae of the Sakhalin sole Limanda sakhalinensis were studied by observing specimens obtained in a rearing experiment from fertilized eggs to the juvenile stage. The wild broodstock was collected in January 2010 and kept in a circular water tank (${\O}1.5{\times}1m$) at a temperature of $14.5{\pm}0.5^{\circ}C$. Fertilized eggs ranged from 0.72 to 0.82 mm ($0.77{\pm}0.07mm$, $mean{\pm}SD$) in diameter. The eggs were spherical, transparent and adhesive demersal. The egg yolk was divided from the oocyte 10 min after fertilization (AF), and an embryo was formed in 36 h AF. More than 50% of the eggs hatched within 133 h AF. The mouth and anus did not open until $3.5{\pm}0.25mm$ total length (TL). At 4, days after hatching (AH), the fish became larvae 3.7 to 4.2 mm ($4.0{\pm}0.36mm\;TL$), yolk absorption was completed and the mouth began to open. The left eye moved upward and the nostril moved to the right at 39 days AH. These post-larvae ranged from 8.0 to 9.9 mm TL ($8.9{\pm}1.33mm\;TL$). At 50 days AH, the fish became juveniles ($12.4{\pm}1.20mm\;TL$) There were 70-72 dorsal fin rays, 55-56 anal fin rays, 11 pectoral fin rays, and 6 ventral fin rays and the juveniles adopted a benthic life.

• 한국양식학회지
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• 제7권2호
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• pp.109-122
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• 1994

천연 및 인공 넙치 종묘의 성장 단계에 따른 체지질 조성 변화를 비교 검토한 결과는 다음과 같다. 1) 어체의 지질 및 비타민 E 함량은 천연 종묘 보다 인공 종묘에서 높은 값을 나타내었다. 2) 어체 성장에 따른 지질, 지방산(18: 2n-6, 22: 6n-3) 및 비타민 E 함량 변화는 부화 후 전장 5-10mm 전후의 배합 사료 공급기에서 급격한 증감 현상을 보였다. 3) 어체 지질, 지방산 조성 및 비타민 E 함량은 먹이 조성에 직접적인 영향을 받았다. 4) 천연 종묘는 인공 종묘에 비해 자연 상태에서 지질 함량이 낮고 고농도의 DHA를 함유하고 있는 천연 먹이를 섭취한 것으로 추정되었다.

• 한국수산과학회지
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• 제51권5호
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• pp.549-555
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• 2018

The objectives of this study were to confirm the nutritional requirements and improve the survival of the walleye pollock Theragra chalcogramma, a cold seawater fish, by enrichment. We analyzed the fatty acids and amino acids of fertilized pollock eggs before hatching, just-hatched larvae, larvae that had absorbed only the yolk sac, and larvae starved for 2 days after yolk absorption. For the survival improvement experiment, we administered docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and DHA-EPA enrichment. Fatty acid decreased DHA and EPA content. On the $30^{th}$ day, body growth was significantly greater in pollock given the EPA and DHA-EPA treatments (P<0.05). Larval survival at 20 and 30 days after hatching (DAH) was greatest under the DHA-EPA treatment (P<0.05). Survival was significantly lower under the EPA treatment at 10 DAH, but then increased to approach that seen under the EPA-DHA treatment (P<0.05). Therefore, we determined that reduced survival in hatchlings of high-mortality pollack could be improved by controlling EPA and DHA content during enrichment. We conclude that cold seawater fish must be given feed that meets their nutritional needs, which can be accomplished using newly manufactured enrichment products for the larvae of cold seawater fish, such as pollock.

• 한국수산과학회지
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• 제32권3호
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• pp.295-302
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• 1999

여수주변해역에서 부유성 어란과 치자어의 분포 조사가 1996년 8월, 11월과 1997년 1월, 4월에 실시되었으며 조사기간 중 어란은 4종, 치자어는 24종이 동정되었다. 어란은 멸치 (Engraulis japonicus)가 전체 어란 출현량의 $80.6\%$로 가장 높았고, 다음은 동갈양태류 (Callionymidae spp.) ($1.6\%$), 그리고 전어 (Konosirus punctatus)와 앨퉁이 (Maurolicus muelleri)는 $1.0\%$ 미만으로 출현량 비율이 매우 낮았으며 기타 미동정 어란은 $17.8\%$를 차지하였다. 치자어의 출현 종 수는 여름철에 17종으로 가장 많았고, 봄철에 4종으로 가장 적었다. 어종별 출현비율은 동갈양태류가 전체 치자어 출현량의 $25.7\%$로 가장 높았고 망둥어류 (Gobiidae spp.)가 $23.5\%$, 청보리멸 (Sillago japonica)이 $17.2\%$, 멸치가 $12.2\%$, 앞동갈베도라치 (Omobranchus elegans )가 $9.9\%$를 차지하였으며 그 외의 종은 모두 $2.0\%$ 미만이었다. 여수주변해역의 치자어는 망둥어류, 동갈양태류, 쥐노래미등의 연안성 어종과 비록 출현량은 작지만 제주도 주변해역을 통과하는 난류수의 영향으로 출현한 몽치다래류, 만새기, 자리돔 등과 같은 난류성종으로 구성되어 있었다.