• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.294-304
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• 2023

Seasonal variations in the community structure of larval fish assemblage in the coastal waters off Gadeok-do were investigated in May, August and November of 2019, and February in 2020. During the study period, a total of 85 larvae species belonging to 45 families were collected. The dominant species were Engraulis japonica, Gobiidae sp., Clupea pallasii, Decapterus maruadsi, and Callionymidae sp.. These five species accounted for 84.1% of the total number of larvae during the survey period. E. japonica, Gobiidae sp., D. maruadsi, and Callionymidae sp. were the dominant species in the summer, while C. pallasii was the dominant species in the winter. The Species Diversity Index was highest in the summer and lower in the fall and winter months, with the lowest values in the spring. As a result of cluster analysis using the number of individual larval fish showed that they are divided into four seasonal groups. In particular, due to seasonal changes in water temperature, an appropriate growth environment was formed in the summer, and an appropriate hatching water temperature for winter spawning fish species was formed in winter, reflecting the seasonal characteristics of the larval fish community.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.297-302
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• 2007

An investigation of fish fauna was conducted based on the specimens from the Taean International Marine Park, off West Coast of Korea in 2005. They were collected by small seine net and stake net. The collected fishes were composed of 27 species belongs to 15 families and 8 orders. The dominant species were gobids of Favonigobius gymmnauchen in the sand area, Chamichthys gulosus and C. dolichognathus in the rocky area. The Korean endemic species were two species of Zoarchias uchidai and Repomucenus koreanus. But Porocottus leptosomus that described as a new species on the basis of specimens collected from this area in 2002 was not collected in this study.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.187-194
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• 2005

Feeding of the maiden goby, Pterogobius virgo and multicolorfin rainbowfish, Halichoeres poecilopterus, was studied at Kurahashi Island in the Seto Inland Sea, Japan. P. virgo foraged on only benthic invertebrates in a pit on the bottom by spot-fixed fin digging. Territory size of P. virgo was very small, because they only defended the excavated pit. H. poecilopterus frequently intruded into the feeding territory of P. virgo and fed on benthic invertebrates flushed out by the fin digging of P. virgo. Feeding activity and vigilance time of P. virgo tended to decrease significantly more in such an association than when solitary. Frequency of aggression of P. virgo when H.poecilopterus intruded into the territory was higher the intruder came from the front of the territory than when the invasion was from the side and back, regardless of the size of the intruder. In small H.poecilopterus, feeding success rate was greater from the side and back of the territory than from the front. However, similar-sized H.poecilopterus were more successful in feeding from the front and side. Feeding association provides an antipredatory benefit to P. virgo because of less alert time against predators and earlier detection of predators, although their cost is great because of territory defense and decrease of feeding activity.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.210-219
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• 2008

Monthly variation in species composition of upstream-migrating fish in the Cheonjeyeon Estuary was determined by analyzing fish data collected January~September 2004 and January~August 2007. Fish migrating from the sea to freshwater through the channels were collected by a rectangular net with a mesh size of 2 mm during the day and at night in the new moon. Of 14 species collected, ayu (Plecoglossus altivelis altivelis) and mullet (Mugil cephalus) predominated in abundance. Glass eels (Anguilla japonica) occurred mainly during the night from February to May. Other fishes collected included brackish-water gobiids (Gymnogobius urotaenia, Rhinogobius giurinus, Tridentiger obscurus, and Sicyopterus japonicus), freshwater fishes (Misgurnus anguillicaudatus and Rhynchocypris oxycephalus), and coastal marine fishes (Engraulis japonicus, Pempheris japonica, Plotosus lineatus, Takifugu niphobles, and Terapon jarbua). Ayu occurred during almost all sampling periods. They ranged principally from 55 to 100 mm total length (TL), with some fish larger than 100 mm TL collected after April. Mullet also occurred during almost all sampling periods. They ranged principally 25~58 mm TL, with some larger fish of 103~240 mm TL collected in February and April. That only a few freshwater and brackish-water fishes occurred in the study area is probably related to the freshwater systems having long been isolated from the continental systems and to the poorly developed estuaries in Jeju Island reflecting limited river discharge.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.128-134
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• 2011

The feeding habits of scorpion fish, Sebastiscus marmoratus, were studied using 324 specimens collected in the coastal waters of Tongyeong, from January to December, 2009. The size of the specimens ranged from 9.8 to 30.1 cm in standard length (SL). S. marmoratusis was a piscivore that consumed mainly teleosts such as Engraulis japonicus, Clupea pallasi and gobid fishes. Of the fish species Engraulis japonicus was the most preferred prey. Its diet also includes shrimps and crabs. Hermit crabs, polychaetes, bivalves and euphausia were minor preys. Smaller individuals (<13 cm SL) fed mainly on shrimps, crabs and fishes. The proportion of shrimps and crabs decreased as body size increased, whereas the consumption of fishes gradually increased. Fishes accounted for almost stomach contents of larger individuals (more than 19 cm SL). Seasonal changes in the S. marmoratusis diet were significant. Fishes was most common prey during summer, autumn and winter, whereas crabs and shrimps were mainly consumed during spring.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.317-320
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• 2015

The one specimen of Astrabe fasciata, belonging to the family Gobiidae was collected from the Dokdo of East Sea in Korea, and described as the first record from Korea. The specimen is characterized by having two dorsal fins, pectoral fin with free rays (five upper, two lower), protrusion on upper posterior part of supraorbital dermal fold, white spots dispersed on head and five white transverse bends on the body. We proposed its Korean name "Dok-do-eol-ruk-mang-duk-sok" and "Dok-do-eol-ruk-mang-duk" for the genus and species, respectively.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.202-211
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• 2014

Feeding ecology of Luciogobius guttatus (Flat-head goby) populations were investigated on the Youngjong, Incheon, Korea. In total, 257 individuals ranging from 13.4 to 57.5 mm standard length SL were analyzed. L. guttatus was studied in the Tide-pool from January 2010 to December 2010 monthly. The stomach contents of L. guttatus consisted mainly of Copepods and Brachyurans. Amphipods, Anomurans, Cumaceans, Macrurans, Insects and small stones were also observed. As a result, the benthic crustaceans were important food for this species. Harpacticoid spp. (Copepods) and Hemigrapsus spp. (Brachyurans) were major prey organisms for all fish size and seasons.

• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.1-7
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• 2021

Using stereo, light, and scanning electron microscopes, we researched the anatomical and histological structure of Chaenogobius gulosus's olfactory organ and compared it to those of sympatric gobies Luciogobius guttatus and Favonigobius gymnauchen. Results revealed the following common characteristics: i) tubular anterior nostril (AN) and flat posterior nostril (PN), ii) a single longitudinal lamella, iii) two accessory nasal sacs (ANS, ethmoidal and lacrimal), iv) abundant sensory epithelium lymphatic cells (LC), v) an eosinophil cell, and vi) a ciliary length a quarter of the knob diameter in the olfactory receptor neuron (ORN). Some characteristics are specific to C. gulosus and different from the other two gobies: i) 0.5~1.0 mm AN and 0.2~0.5 mm PN (vs. 0.2~0.3 mm and 0.2~0.3 mm in L. guttatus; 0.2~0.4 mm and 0.1~0.3 mm in F. gymnauchen), ii) two ANS (vs. absence in L. guttatus; two in F. gymnauchen), iii) abundant LC (vs. low in L. guttatus and F. gymnauchen), iv) low density non-sensory cilia on the lamellar surface (vs. high in L. guttatus; low in F. gymnauchen), and v) a quarter ciliary length to knob diameter ratio in the ORN (vs. mixture of a quarter to equal ratio in L. guttatus; two or three times in F. gymnauchen). From these results, we confirmed the C. gulosus olfactory organ has adapted anatomically and histologically to the sand-rock tidal zone.

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.58-67
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• 2024

The purpose of this study was to find out the fish species that appeared monthly through the fish stock survey of Minyang eelgrass beds in Tongyeong and compare them with the results of previous studies in the same area. This survey confirmed the species compositional characteristics of fish using surf net from March 2021 to February 2022. During the survey period, a total of 24 species, 8,679 individuals, and 3,714.42 g of the total fish were collected. The dominant species were Gymnogobius castaneus, G. heptacanthus, Chaenogobius gulosus, Pholis nebulosa, Rudarius ercodes which accounted for 95.9% of a total number of individuals collected. Similar to previous studies, most of the fish species that appeared were gobiidae, and in this study. Leiognathus nuchalis, which was selected as pollution indicator species, appeared for the first time.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.48-60
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• 1997

The species composition and seasonal variations of fish community in the Zostera marina belt at the coastal water off Hamduck, northern part of Cheju Island, were analyzed based on day and night samples collected by a small beam trawl from May 1993 to May 1994. The dominant species among the 58 fish species in 35 family were tubesnout, Aulichthys japonicus, gobie, Pterogobius zonoleucus, filefish, Rudarius ercodes, pipefish, Syngnathus schlegeli and sea catfish, Plotosus lineatus. These species comprised 86.1% in the number of individuals and 62% in biomass. The number of individuals and biomass were high between October and December, and low between January and April. About 90% of fishes were noncommercial and small-sized fishes, less than 14cm in total length. The larvae and juvenile fishes were collected in the study area throughout the year. The recruitments of dominant species were related to the seasonal variations of Z. marina utilized as a shelter or feeding ground. A japonicus, P. zonoleucus, Zoarchias glaber and Hexagrammos agrammus recruited between January and June, and R. ercodes, S. schlegeli, P. lineatus and Petroscirtes breviceps between July and December.