• Title, Summary, Keyword: Larval fish

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Quantitative fluctuation and species composition of ichthyoplankton in Gwangyang Bay, Korea (광양만 연안에 분포하는 부유성 난 및 자치어의 종조성과 양적변동)

  • CHU, Bo-Ra;LEE, Sung-Hoon;YU, Tae-Sik;HWANG, Tae-Yong;HAN, Kyeong-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.3
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    • pp.233-242
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    • 2019
  • Species composition and yearly variation of fish eggs and larval fishes were investigated from 2014 to 2016. During the study period, the fish eggs were identified as belonging to 14 taxa. The dominant species of fish eggs were Leiognathus nuchalis, Engraulis japonicus, and Konosirus punctatus. These three species accounted for 97.4% of the total number of individuals collected. The collected larval fishes were identified into 37 taxa, 22 families, and seven orders. The dominant species of larval fish were Leiognathus nuchalis, and Gobiidae fishes. These three species accounted for 85.4% of the total number of individuals collected. The diversity index of the larval fishes was the highest in 2014 (H' = 1.60) and the lowest in 2015 (H' = 1.15). The evenness index was the highest in 2016 (J = 0.51) and the lowest in 2015 (J = 0.39). The dominance index was the highest in 2015 (D = 83.5%) and the lowest in 2016 (D = 70.9%). In addition, the economically important species in this area were Engraulis japonicus, Konosirus punctatus, Hippocampus coronatus, Sebastes schlegelii, Acanthopagrus schlegeli, and Cynoglossus joyneri.

Proper Sampling Method for Larval Fish in the Western coastal Waters (서해 연안역에서 자어의 적정 채집 방법)

  • 차성식;박명정
    • 한국해양학회지
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    • v.30 no.1
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    • pp.64-68
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    • 1995
  • To investigate a proper sampling method for larval fish in the western coastal waters, the abundances of larval fish sampled at upper and lower layers during the day and nighttime were compared. The difference in the abundances at upper and lower layers seems to be related to the diurnal vertical migration of larval fish. Therefore, samples at upper layer during the day causes an underestimation of the number of species and the abundance. As the abundances through whole water column during the day is not significantly smaller than during the nighttime. samples obtained by oblique tow through whole water column during the day can be used to estimate the abundance of fish larvae.

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Comparison of Larval Fish Survival of Pale chub (Zacco platypus) Exposed to Different Levels Turbidity (탁수조건에 따른 피라미 치자어의 생존률 비교)

  • Moon, Woon-Ki;Bae, Dae-Yul;Jung, Myoung-Sook;Lee, Sang-Don;Kim, Jai-Ku
    • Korean Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.314-321
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    • 2012
  • To quantitatively assess the effects of turbidity on egg development and larval fish survival, a laboratory fish rearing experiment was applied to different life stages (newly hatched larval stage, juvenile stage and pre-adult stage) of the Zacco platypus, one of the most universal and tolerant species in Korea. According to the stress index of turbidity in water with exposure time, three different treatments, including a reference condition (1~7 NTU) as well as intermediate (20~150 NTU) and high turbidity conditions (400~1,000 NTU) were applied, and egg hatching and larval fish mortality rates were observed. The mortality rates of newly hatched larval fish were significantly different among treatments (ANOVA, $F_{2,3}$=17.79, p<0.05). Average rates of survival to hatching were 20.9% (${\pm}0.1%$) for reference condition, 11% (${\pm}6.9%$) for intermediate level and 3.2% (${\pm}3.7%$) for high level conditions, respectively. A sudden change of mortality at the high level was observed within 5 days of the experiment. About 84% of juvenile fish survived until 20 experimental periods under conditions of reference turbidity, while survival under conditions of intermediate turbidity was over 80% of larval fish until day 13 of the experiment, but dropped to less than 10% after day 14 and 15 of two experiments. Fish mortality appeared from day 6 of the high turbidity experiment, and 50% mortality was achieved at day 9 to 10 of experiment. Full mortality occurred at day 14 of the experiment (RM-ANOVA, $F_{2,38}$, p<0.005). In the pre-adult stage experiment, no mortality was observed during the experiment at reference level treatment (20 days), while only slight mortality rates were observed for both intermediate and high levels until day 5 of the experiment, however, no further fish died in either experiment. It was significantly different compared to reference condition (RM-ANOVA, $F_{2,20}$=8.28, p<0.01), but no difference was observed between intermediate and high level conditions. Consequently, this tolerant species has been determined to be well adapted to high levels of turbidity in its adult stage, but more vulnerable throughout earlier life stages.

Larval Anisakid Infections in Marine Fish from Three Sea Areas of the Republic of Korea

  • Cho, Shin-Hyeong;Lee, Sang-Eun;Park, Ok-Hee;Na, Byoung-Kuk;Sohn, Woon-Mok
    • The Korean Journal of Parasitology
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    • v.50 no.4
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    • pp.295-299
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    • 2012
  • The present study was performed to determine the infection status of anisakid larvae in marine fish collected from 3 sea areas of the Republic of Korea. Total 86 marine fish (8 species) collected from the East Sea (Goseong-gun, Gangwon-do), 171 fish (10 species) from the South Sea (Sacheon-si, Gyeongsangnam-do), and 92 fish (7 species) from the Yellow Sea (Incheon Metropolitan City) were examined by both naked eyes and artificial digestion method. Among the total of 349 fish examined, 213 (61.0%) were infected with 8 species of anisakid larvae, i.e., Anisakis simplex, 6 types of Contracaecum spp., and Raphidascaris sp., and the mean larval density was 13.8 per infected fish. Anisakid larvae were detected in 45 fish (52.3%) from the East Sea, 131 fish (76.6%) from the South Sea, and 37 fish (40.2%) from the Yellow Sea. The average numbers of larvae detected were 4.0, 16.6, and 15.9, respectively. Anisakis simplex larvae were detected in 149 fish (42.7%), and the mean larval density was 9.0 per infected fish. They were found in 26 fish (30.2%) collected from the East Sea, 96 fish (56.1%) from the South Sea, and 27 fish (29.3%) from the Yellow Sea. The average numbers of larvae detected were 2.9, 10.3, and 10.5, respectively. Conclusively, the present study suggests that the infection rate and density of anisakid larvae are more or less higher in the fish from the South Sea than those from the East Sea or the Yellow Sea.

Spatio-temporal Variations in Species Composition and Abundance of Larval Fish Assemblages in the Nakdong River Estuary, Korea (낙동강 하구역 부유성 자치어 종조성의 시·공간 변동)

  • Choi, Hee Chan;Park, Joo Myun;Huh, Sung Hoi
    • Korean Journal of Ichthyology
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    • v.27 no.2
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    • pp.104-115
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    • 2015
  • The species composition of larval fish assemblages in the Nakdong River estuary, Korea, was determined using monthly samples collected between September 2010 and August 2011 at two stations. A total of forty three larval species were collected during the study. Among forty three taxa of fish larvae, summer gobies, Clupea pallasii, Engraulis japonicus, spring gobies, Konosirus punctatus, winter gobies, Sardinops melanostictus, Coilia nasus were dominant taxa, and these eight taxa accounted for 95.0% in the total number of individuals. Species composition and abundance varied greatly spatio-temprally showing the peak abundances of fish larvae in August 2011, and a few fish larvae were occurred in November 2010. Cluster analysis based on the number of individuals of fish larvae showed that 21 month-station sampling units were classified into five groups at the similarity level of 50%, and the results of ANOSIM and SIMPER analysis revealed significant differences in community structure among five groups.

Seasonal Variation of Larval Fish Community in Jinhae Bay, Korea (진해만 자어 군집의 계절 변동)

  • Moon, Seong Yong;Lee, Jeong-Hoon;Choi, Jung-Hwa;Ji, Hwan Sung;Yoo, Joon-Taek;Kim, Jung-Nyun;Im, Yang Jae
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.140-149
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    • 2018
  • Seasonal variations in the community structure of larval fish assemblage in Jinhae Bay were investigated in February, May, August and November of 2015, and in the same months in 2016. During the study period, a total of 28 larvae species belonging to 24 families were collected. The dominant species were Clupea pallasii, Liparis tanakae, Callionymidae sp., Sillago japonica, Ernogrammus hexagrammus and Engraulis japonica. These six species accounted for 77.6% of the total number of larvae during the survey period. The larvae of C. pallasii and L. tanakae were exclusively caught in February 2015 and 2016, while those of Apogon lineatus and Sillago japonica were exclusively caught in August 2015 and 2016. Overall, species diversity of the fish larvae was highest in February and August, although it was relatively low in May. The results of the non-metric multidimensional scaling (nMDS) analysis using the number of individual larval fish showed that they are divided into four seasonal groups. Our results showed that the community of larval fish in Jinhae Bay was affected by seasonal changes in temperature and the emergence of spawning fish species. Additionally, we suggest that the high abundance of larval fish came from around Jam-do and the northern part of Chilcheon-do; these locations are the main spawning grounds of Jinhae Bay.

The Life History and Morphological Changes of Daphnia (D. pulex and D. galeata) Induced by the Larval Damselfly (Cercion sp.) and Fish (Micropterus salmoides) Kairomones (실잠자리 유충과 어류에서 분비된 카이로몬에 의한 물벼룩류의 생활사와 형태변화)

  • La, Geung-Hwan;Jo, Hyo-Nyeo;Choe, Hyeon-Ju;Kim, Hyun-Woo
    • Korean Journal of Ecology and Environment
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    • v.42 no.1
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    • pp.107-114
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    • 2009
  • We investigated the predation behavior of larval damselfly on Daphnia pulex and D. galeata, and compared the life history and morphological defenses in two Daphnia species against larval damselfly and fish kairomones. Larval damselflies showed size-dependent predation behavior and preyed upon smaller daphnids easily regardless light condition. Overall, small D. galeata juveniles were more vulnerable than D. pulex to the larval damselfly predation. D. pulex displayed life history and morphological changes as the anti-predator defenses against larval damselfly as well as large mouth bass, while D. galeata showed the anti-predator defenses to the large mouth bass. Thus, our results revealed that two Daphnia species exhibits different anti-predator defense strategy to increase survivorship.

Species Composition of Ichthyoplankton in the Coastal Water between Yeosu and Namhae, Korea (여수와 남해 연안에 분포하는 부유성 난 및 자치어의 종조성)

  • KOH, Su-Jin;SEO, Su-Hyeon;LEE, Sung-Hoon;YU, Tae-Sik;HAN, Kyeong-Ho
    • Korean Journal of Ichthyology
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    • v.31 no.3
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    • pp.159-164
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    • 2019
  • Species composition and seasonal variation of fish eggs and larvae were investigated from 2017 to 2018. During the study period, the fish eggs were identified as belonging to 6 taxa. The dominant species of fish eggs were Engraulis japonicus, Leiognathus nuchalis, and Konosirus punctatus. These three species accounted for 96% of the total number of individuals collected. The collected larval fishes were identified into 17 taxa, 11 families, and 5 orders. The dominant species of larval fish were Engraulis japonicus, Leiognathus nuchalis, and Konosirus punctatus. These three species accounted for 70% of the total number of individuals collected. The diversity index of the larval fishes was the highest in summer (H'=1.78) and the lowest in winter (H'=1.34). The economically important species in this area were Engraulis japonicus, Konosirus punctatus, Sebastes schlegelii, Cynoglossus joyneri and Stephanolepis cirrhifer.

Effects of feeding rate and number of meal on growth and body composition of ayu Plecoglossus altivelis

  • Cho, Sung-Hwoan;Lee, Jong-Kwan;Lee, Jong-Ha;Lim, Young-Soo;Park, Jung-Youn;Lim, Han-Kyu;Lee, Sang-Min
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • pp.319-321
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    • 2001
  • Supply of ntrition-balanced feed is very important for growth of fish, especially for growth of early period of fish. Therefore, most of commercial feeds for larval and juvenile fish are relatively expensive due to high level of the several nutrients to satisfy their requirements for growth. Overfeeding larval fish may increase fish production cost because of larvae feeds high price and deteriorate water quality, eventually reduce growth of fish. (omitted)

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Occurrence of scutica-like ciliate (SLC) and its control during the mass seed production of the Japanese scallop, Patinopecten yessoensis (참가리비 (Patinopecten yessoensis) 대량 종묘생산시의 Scutica-like ciliate 발생 및 대책)

  • Jo, Q-Tae;Bang, Jong-Deuk;Kim, Su-Kyeong;Rahman, Mohamad M.;Gong, Yong-Geun;Kim, Dae-Kwon;Lee, Joo-Seok
    • Journal of fish pathology
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    • v.21 no.3
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    • pp.167-174
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    • 2008
  • Few studies on parasitic scutica-like ciliates (SLCs) influencing larval growth and survival during the seed production of the Japanese scallop, Patinopecten yessoensis have been performed in spite of relatively high magnitude of their infectious damage to the larvae. In the mass seed production of the scallop, SLCs were never infectious during D-larval stage which lasted 6 to 7 days. Indeed, the infection first occurred in 2 to 4 days after first umbo-staged larvae. A regular selection of active larvae in swimming behavior kept larval SLC infection low throughout the culture compared to unselected control (P<0.05) in which all the larvae alive were contained. Higher infection frequencies of the unselected control resulted in lower larval survivals and wider range of larval size distribution that drove larval attachment rate lower. To the worse, the nursery spats from the higher SLC infection exhibited a retarded growth and elevated occurrence of abnormal scallop.