• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.829-836
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• 2017

This study investigated the species composition and abundance of floating fish eggs to determine the timing and location of spawning of fish inhabiting the coastal waters of Sagye, Jejudo Island. Eggs were collected with a Bongo net bimonthly from May 2009 to February 2010. Identifications were based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Eggs were determined to belong to 43 distinct taxa, 35 of which were identified to the species level. The assemblage spanned eight orders, 23 families, and 32 genera. The number of taxa collected varied from month to month, with 14 taxa (12 species) found in June 2009, 11 taxa (10 species) in October 2009, 10 taxa (nine species) each in August 2009 and February 2010, eight taxa (six species) in April 2009, and five taxa (four species) in December 2009. Five abundant species (Branchiostegus japonicus, Engraulis japonicus, Pseudolabrus sieboldi, Goniistius zonatus, and Halichoeres tenuispinis) together represented 52.8% of the total number of eggs collected during the study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.20-28
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• 2005

Species composition and seasonal variation of decapod crustacean assemblage in Hampyeong Bay, Korea were examined. Sampling was monthly made by a shrimp trawl between March 2003 to February 2004. A total of 39 species of 20 families were collected. Of these, Latreutes planirostris, Palaemon gravieri, Parapenaeopsis tenella, Exopalaemon carinicauda, Charybdis japonica, Trachysalambria curvirostris and Palaemon macrodactylus were dominant species comprising $84.3\%$ of the total number of individuals. Charybdis japonica, P. gravieri, Oratosquilla oratoria, E. carinicauda, T curvirostris, Metapenaeus joyneri and P. tenella represented $90.6\%$ of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in summer. Cluster analysis, based on monthly abundance data of the 14 most common species, showed that the species were separated into three different groups. Group A composed of Leptochela gracilis, Alpheus japonicus, Crangon uritai, P. macrodactylus, E. carinicauda, P. gravieri, O. oratoria, C. japonica, which were year round residents, group B M. joyneri, T. curvirostris and P. tenella, which were abundant in summer, and group C Crangon hakodatei, Latreutes anoplonyx and L. planirostris, which were abundant in winter. Principal component analysis revealed that seasonal variation in the decapod crustacean assemblage was attributed to the abundance of temporal species such as penaeid shrimps, which were abundant in summer, due to seasonal variation of water temperature and reproductive pattern.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.727-738
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• 1998

Seasonal species composition of fishery resources was determined using samples collected by a stow net from April 1995 through January 1996 at 9 stations off Youngkwang. Catch data obtained from a set net using strong tidal current could be used for a quantitative analysis of dominant species. Of the 98 species identified, assemblages were consisted of $52.0\%$ in fishes, $44.6\%$ in shrimps, $2.0\%$ in cephalopods, $1.4\%$ in crabs and <$0.1\%$ in gastropods. Thryssa kammalensis, Crangon hakodatei, Metapenaeus joynezi and Johnius grypotus predominated in abundance, consisting of $68\%$ in the number of individuals, The abundance and species composition fluctuated seasonally, and species could be distinguished by life history pattern with seasons. Seasonal variation in species composition was greater than the spatial variation in a sampling period, As the fine sediment was predominated in the study area, the species composition were significantly different from those of other coastal waters of West Sea, Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.264-273
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• 2014

To investigate species composition and seasonal variation of demersal organisms in the coastal waters off the Taean peninsula, otter trawl surveys were conducted from April 2010 to January 2011. A total of 75 species were collected, including 44 species of Pisces, 19 species of Crustacea, 6 species of Cephalopoda, 4 species of Gastropoda, and 1 species each of Bivalvia and Echinoidea. The dominant species in each season were Palaemon gravieri in spring, Charybdis bimaculata in summer, Loligo japonica in autumn, and Crangon hakodatei in winter. The number of species, individuals and biomass were highest in autumn and lowest in winter. The diversity index was highest in summer and lowest in winter. The dominance index was highest in winter and lowest in summer. The richness index was highest in autumn and lowest in winter. The evenness index was highest in summer and lowest in autumn. A cluster analysis showed that demersal organisms were divided into two groups; spring and winter organisms (Group 1) and summer and autumn organisms (Group 2). We detected a significant difference (P<0.05) between these groups, mainly owing to Platycephalus indicus, Repomucenus koreanus, and Paralichthys olivaceus within Pisces: Trachysalambria curvirostris, Metapenaeopsis dalei, P. gravieri, and C. hakodatei within Crustacea: and L. japonica within Cephalopoda.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.231-236
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• 2009

This study describes biological environmental characteristics in natural habitats of Haliotis diversicolor in the coastal area of Sungsanpo located in the eastern coast of Jeju-do, Korea. The field survey was monthly conducted from May 2006 to February 2007. H. diversicolor, sea urchin, turban shell and marine algae were collected by two divers using SCUBA. The species composition of demersal fishes were seasonally investigated by fish traps in 2007. During the study period, more than 67% of H. diversicolor and sea urchin were found in the depth shallower than 5 m, and more than 64% of turban shell were found in the depth deeper than 3 m. The dominant algal species in May were generally Undaria pinnatifida, Ecklonia cava, Sargassum. spp. and coralline algae. Most of demersal fishes collected by the fish traps were wrasses which have been reported as a major predator of young abalone.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.81-88
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• 2018

A study for species composition and abundance of the fish assemblages in the eastern Jinhae Bay, Korea was conducted using monthly larval collection by a RN80 net from October, 2010 to September, 2011. Of all the 45 species collected, the dominant species were Clupea pallasii, Hexagrammos otakii, Pholis fangi and Engraulis japonicus. Clupea pallasii, Hexagrammos otakii, Pholis fangi in winter and examined Engraulis japonicus, Acanthogobius sp., Parablennius yatabei, and Tridentiger trigonocephalus in summer appeared seasonally. Popoulation characteristic by stations was not clear seasonally and spatially, and appearance aspects of dominant species were similar by stations. Compared our results with other studies in the South Sea, dominant species and their appearance period were similar to their spawning period. Finally, the appearance period of the larvae in the South Sea was closely resulted to spawning period rather than the regional characteristic.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.320-326
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• 2019

The diet composition of Arctoscopus japonicus was studied using 448 specimens collected in the coastal waters of East Sea, Korea. The size of the specimens ranged from 6.2-25.3 cm in total length (TL). A. japonicus were fed mainly on amphipods that constituted 76.1% in IRI. Euphausiids were the second largest prey component. The diets also include small quantities of crabs, copepods, mysids, cephalopods, monogeneans, and fishes. A. japonicus showed ontogenetic changes in feeding habits. Smaller individuals (6-10 cm, TL) fed mainly on amphipods. The proportion of amphipods decreased as body size increased, whereas the consumption of euphausiids gradually increased (10-14 cm, TL). As the body size more increased, the proportion of amphipods increased whereas euphausiids decreased (14-26 cm, TL).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.1
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• pp.53-57
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• 2007

We examined seasonal variation In the abundance and species composition of shrimp communities in Doam Bay and around Naro-do, Korea. Samples were collected monthly from March 2001 to February 2002 (Doam Bay) and from December 2000 to November 2001 (Naro-do) usinga beam trawl. A total of 19 shrimp species representing eight families were collected from Doam Bay. The dominant species were Exopalaemon carinicauda, Trachysalambria curvirostris, Parapenaeopsis tenella and Crangon hakodatei, which accounted for 92.6% of individuals and 92.8% of biomass. In the Naro-do area, a total of 18 shrimp species representing eight families were collected. The dominant species were C. hakodatei and P. tenella, which accounted for 78.6% of individuals. Exopalaemon carinicauda, T. curvirostris, P. tenella, C. hakodatei and Metapenaeus joyneri accounted for 89.6% of biomass. In each season, the pattern of species appearances differed in the two areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.5
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• pp.353-362
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• 2008

The fish species composition and variation in the Youngil Bay, East Sea of Korea, were investigated every month from January, 2001, to December, 2002, using gill nets for sample collection. A total of 63 fish species belonging to 31 families under 10 orders, and a total of 40 species belonging to 26 families under 8 orders, were identified in 2001 and 2002, respectively. Of these, the families Pleuronectidae (9 species), Scorpaenidae (8 species) and Cottidae (5 species) were dominant in 2001, whereas Pleuronectidae (4 species), Cottidae (3 species) and Hexagrammidae (3 species) were dominant in 2002. The number of species recovered was the highest in August, 2001 (34 species) and January and September, 2002 (14 species each), and lowest in May, 2001 (6 species) and December, 2002 (5 species). The principal component analysis for each year showed that fish species composition differed over time even within the same sample area. In addition, the relationship between PC scores and temperature showed a positive relationship in 2001, but a negative relationship in 2002.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.728-733
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• 2023

The diet composition of octopus Octopus vulgaris was studied using 392 specimens collected from January to December 2020 in the coastal waters of Yeosu, Korea. The body weight ranged from 86.4 to 3,645.4 g. The most important prey item in the diet of O. vulgaris was decapods, which constituted 43.9% in ranking index (%RI). The second largest prey item was Pisces (%RI=27.9%), and cephalopods (%RI=21.8%) constituted the third largest prey item. The average trophic level of O. vulgaris was 3.97±0.59. Ontogenetic changes were significant among size classes (<400 g, 400-800 g, ≥800 g). The small size class (<400 g) mainly fed on decapods, whereas the medium (400-800 g) and large size (≥800 g) classes mainly fed on cephalopods and Pisces, respectively. The dietary composition varied significantly with season.