• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.337-345
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• 2007

Changes of feeding habitat and feeding organ of a land-locked sweetfish, Plecoglossus altivelis related to their growth process were investigated in the Lake Okjeong, Sannae-myeon, Jeongeup-si, Jeollabuk-do, Korea from 2004 to 2005. In the lake, the post-larvae from 25 to 40 mm in standard length fed mainly on animal organisms such as Copepoda, Branchiopoda and Rotatoria. Also, the juveniles from 50 to 60 mm (SL) fed on Chironomidae of Diptera, Copepoda and Branchiopoda. However, the juvenile from 60 to 70 mm (SL) in the Churyeong Stream fed on animal organisms and aquatic algae, the immature fishes more than 70 mm (SL) fed on only periphyton such as Synedra, Cymbella, Navicula and Pinnularia. Also, the feeding organs of the tooth and stomach were changed according to its growth and food change.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.803-813
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• 1994

Eight species belonging to three genera in the family Cynoglossidae of Korea are reviewed and provisional keys to species and genera are provided, with synonyms and their distribution. Among them six species collected from 1992 to 1993 are redescribed and figured in the present study; Cynoglossus interruptus, C. joyneri, C. robustus, C. semilaevis, C. abbreviatus and Paraplagusia japonica. Three species of Areliscus rhomaleus. A. trigrammus, and A. hollandi were considered as synonyms of Cynoglossus semilaevis, C. abbreviatus and C. gracilis respectively. Many tonguefishes inhabit commonly in the western and southern coast of Korea. And although Cynoglossus interruptus and C. abbreviatus are restricted only in the southern coast, C. semilaevis in the western and southwestern coast of Korea, Paraplagusia japonica occurs widely along all of the coasts of 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.2
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• pp.168-175
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• 2013

The feeding habits of the black-edged sculpin Gymnocanthus herzensteini were studied using 944 specimens collected from February 2011 to January 2012 in the coastal waters off Mukho, Gangwondo, Korea. The G. herzensteini ranged from 11.8 to 36.3 cm in total length (TL). The percentage of empty stomachs in G. herzensteini was 40.2%, and the main prey items were Pisces, Euphausiasea, and Macrura. The smallest size group (11.8-15.0 cm TL) consumed mainly Polychaeta and Amphipoda. The quantity of prey increased in proportion to sculpin size. The composition of prey items and feeding habits of G. herzensteini exhibited seasonal fluctuations, that is, the main prey items during spring were Euphausiasea, whereas those during other seasons were Pisces.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.159-166
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• 2005

The karyotypes of three species of Gobiobotia in Korea were investigated: G. macrocephala, G. brevibarba, and G. nakdongensis. In these species, the mitotic chromosomes from 25 groups with two chromosomes each indicated that it is a diploid. The karyotypes of Gobiobotia macrocephala are 2n = 50 (9M+7SM+9ST) with NF = 100, G. brevibarba 2n = 50 (10M+7SM+4ST+4T) with NF = 92, and G. nakdongensis 2n = 50 (5M+9SM+9ST+2T) with NF = 96. Chromosome sizes ranged from 3.3 to $7.5{\mu}m$, 2.7 to $6.3{\mu}m$ and 3.5 to $7.3{\mu}m$ in length, respectively. This is the first report on the chromosomes of G. macrocephala and G. nakdongensis.

• Korean Journal of Ichthyology
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• v.11 no.2
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• pp.109-116
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• 1999

The structure of skin of a mud loach Misgurnus anguillicaudatus was described in relation with their histochemical nature from four regions of the skin. The epidermis has a strongly thick layer of two glandular cells, consisting of a elongate mucous cell and club cell, and a thin layer of superficial layer. The secretion of the elongated mucous cell was acid mucopolysaccharides in nature but the club cell did not give any histochemical reaction. A well defined lymphatic system, comprising small lymphocytes was present in the stratum germinativum layer of the epidermis. A pit organ of a pear-shaped structure was present below the epithelial cells and lie directly on the basement membrane. The organ has blood vessels serving the sense organs of the epidermis. There was a definite area showing acid mucopolysaccharides in the stratum laxum layer of the dermis. Small scales are present deep in the dermis except the top of the head. A great number of blood capillaries were found just under basement membrane. These structural features of skin in M. anguillicaudatus seem to be closely related with cutaneous respiration using air.

• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.74-82
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• 1996

The developmental process of scutes in the eightspine stickleback, Pungitius sinensis kaibarae (Tanaka), was investigated. The scutes appeared first on the caudal peduncle at 13mm and then on the thoracoabdominal part at 16mm. The scutes continued to develop and then the trachurus type of scute arrangement was completed at about 20mm. Finally the number of scutes was stabilized as 32 - 33 in the fish over 22mm. The developmental state of scutes was different according to part of body but most scutes except those of anteriormost part entered into late stage at about 25mm. The scutes of anteriormost part remained as scute of middle stage even though the fish became adults. All scutes were formed around neuromasts of lateral line. Few anterior plates(up to five plates) had additional neuromasts above the plates. But scale material was not accumulated around the additional neuromasts. Relationship between Korean and Japanese eightspine stickleback and the taxonomic meaning of the additional neuromasts were discussed.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.46-54
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• 2018

The habitat characteristics and the age of endangered miho spine loach, Cobitis choii, were investigated in Ji Stream, Guem River, Korea in 2011 to provide baseline data for its restoration. The habitat of the C. choii was the downstream portion composed of sand, and the sand particle sizes was mostly 0.21~1.18 mm (88.7%). Juveniles (age 0+) preferred slower water velocity (0~25 cm/sec) and a lower water depth (5~20 cm) than did individuals who were more than 1 year old, as this group inhabited rapids with 10~25 cm/sec of water velocity and 20~50 cm of water depth. The C. choii rapidly grew during the active period from April to October and they stopped growing during the hibernating period from November to March. The estimated age of the C. choii (females) based on their total length distribution during the spawning period (June) indicated that 1-, 2-, 3- and more than 4-year-old were 40~61 mm, 64~79 mm, 80~91 mm and 92~106 mm, respectively.

• Korean Journal of Ichthyology
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• v.30 no.3
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• pp.155-160
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• 2018

The distribution aspect and extinction threat evaluation of the endangered species, Cottus hangiongensis were investigated from 2011 to 2017 in Korea for this study. The distribution reports of C. hangiongensis were divided into 1954~1985, 1981~2003, 2004~2012, and 2011~2017. The number of habited streams decreased gradually to 30, 24, 10, and 19 streams, respectively. In this study (2011~2017), C. hangiongensis was newly found in two streams (Ayajincheon and Chuksancheon), but 15 streams that appeared in the past are not in this study. The main habitat of C. hangiongensis was the downstream riffle of clean water with fast velocity and cobble-boulder bottoms. Given this evidence as noted for more than a 30% reduction in population after 2003, due to construction wear, river work and the qualitative decline of the habitat, C. hangiongensis is now considered to be Vulnerable (VU A2ac) based on the IUCN Red List categories and criteria.

• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.278-287
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• 2011

Habitat environment, age and feeding ecology of Gobiobotia macrocephala were investigated to provide baseline data for ecological characteristics and recovery in the Seom River at Heungho- ri, Buron-myeon, Wonju-si, Gangwon-do, Korea from 2010 to 2011. G. macrocephala inhabited 10~40 cm in water depth, 8~20 cm bottom size and 40~120 cm/sec in current velocity, and pebble floor were factors to be important for inhabit density. Age group of G. macrocephala in May estimated from the standard length indicated that the 28~42 mm group is 1 year old, the 43~58 mm group is 2 years old, the 59~69 mm group is 3 years old and the 69~85 mm group is more than 4 years old, and the female was 4~10 mm larger than the male. G. macrocephala did mainly feeding with nocturnal fishes between 00 h to 06 h, and they fed mainly Trichoptera (57.7%), Diptera (26.0%) and Ephemeroptera (16.3%). And their small juvenile fed mainly Ephemeroptera and Diptera, however, they ate mainly Trichoptera while growing to adult fish.