• The Korean Journal of Zoology
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• v.33 no.3
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• pp.260-265
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• 1990

Pungitius sinensis specimens were collected from the Namdae River and Chusu River drained into Sea of Japan, and their morphological characters were investigated to determine if this species shows sexual dimorphism. The ratio of the head length to the body length revealed marked sexual difference; the head length in males was longer than in females. The snout length and body depth at anus showed a tendency to be larger in males than in females. This dimorphism seems to be related to breeding habits. The ethological significance of the larger head of males was discussed.

• Korean Journal of Ichthyology
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• v.13 no.4
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• pp.237-247
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• 2001

Three species, Gymnogobius urotaenia, G. sp. 1 and G. sp. 2, which were collected at Hosanriver, Hosan-ri, Samcheock-si, Gangwon-do, Korea, were examined for study of the age and growth. There was no differences between sexes in growth (p>0.05) except in age 0 of G. urotaenia, However, there were differences among the three species (p<0.0001). namely, G. sp. 1 was longer by about 5~10 mm (SL) than the other two species in each age group, while G. sp. 2 was shortest in each age group: G. rotaenia, at age 0 was less than 45 mm, at age 1 to be 45~60 mm, at age 2 to be 60~80 mm, at age 3 to be over 80 mm, and its maximum size was 105.0 mm. G. sp. 1, at age 0 was less than 55 mm, at age 1 55~65 mm, at age 2 65~85 mm, at age 3 over 85 mm and its maximum size was 105.3 mm. G. sp. 2, 0 age was less than 40 mm, at age 1 40~55 mm, at age 2 55~75 mm, at age 3 over 75 mm and its maximum size was 85 mm. Changes of body parts with increasing of body length were examined and analyzed. Covariance analysis showed interspecies differences in the following characters: body depth, head length, caudal peduncle depth, upper jaw length and pelvic fin ray length. G. urotaenia had the highest K-value (the relative growth coefficient) in head length and pelvic fin ray length, and G. sp. 1 had the highest in body depth, caudal peduncle depth and upper jaw length. However, G. sp. 2 had the lowest K-value in these 5 characters.

• Development and Reproduction
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• v.16 no.2
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• pp.101-106
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• 2012

Importance of behavior factors or environmental factors in visual organization and visual function of fish is treated with great care in visual ecology, and there is no study about initial ocular growth and development on the dark banded rockfish, Sebastes inermis. Thus, this study was performed. The total length, head length, head depth, eye diameter and lens diameter of the dark banded rockfish showed positive allometric relationship between parturition stage and 60 days post-parturition (dpp). The increase in total length relative to head length and head depth, head length growth relative to eye diameter and lens diameter, and head depth growth relative to eye and lens diameter were nearly isometric. The eyes were formed completely at parturtion stage. At this age, the eye has an optic nerve fiber layer, a ganglion cell layer, an inner plexiform layer, an inner nuclear layer, an outer plexiform layer, an outer nuclear layer, an outer limiting membrane, a rod and cone layer and an epithelial layer. Thickness of retina at 60 dpp was higher than that of at parturition stage. During this experiment, the proportion of the rod and cone layer, outer nuclear layer, and optic nerve fiber layer of retina were significantly increased, while the proportion of the outer plexiform layer, inner nuclear layer and ganglion cell layer of retina were significantly decreased (P<0.05). The essential demands that must be met by the retina in this species pertain to light sensitivity and spatial resolution.

• Korean Journal of Environmental Biology
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• v.18 no.4
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• pp.387-394
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• 2000

The morphological characteristics between male and female of three species, Chaenogobius urotaenia, C. sp. MR, C. sp. BW, collected from June 1996 to Aug. 1999, Korea was studied. Of 13 characters to be studied, 12 characters with exception of caudal fin ray length were significantly different among three species and these three species were distinguished each other by the results of the multiple comparison test (REGWQ test). Interspecific differences in female was distinct in body depth, head length, caudal peduncle length, caudal peduncle depth, snout length, pectoral fin ray length; In particular, C. sp. MR was shorter in upper jaw length, anal fin ray length and eye diameter, and to be smaller in head depth and head width than other two species. Chaenogobius urotaenia was longer in pelvic fin ray length. In case of male, there was not characters to distinguish each one among three species; Chaenogobius urotaenia was longer in head length, eye diameter and pelvic fin ray length than other two species, C. sp. MR to be longer in caudal peduncle length, but shorter in snout length and anal fin ray length, and to be lower in head depth. C. sp. BW was higher in body depth and caudal peduncle depth, and to be longer in upper jaw length and pectoral fin ray length. Both of male and female among three species didn't have any difference in caudal fin ray length. [Chaeogobius urotaenia, C. sp. MR, C. sp. BW, morphological characteristics].

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.285-290
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• 2008

Morphological characteristics of the cross-bred $F_1$ hybrid between female Paralichthys olivaceus and male Platichthys stellatus were studied. The hybrids showed common biological characteristics of both parents, but showed more morphological similarity to P. stellatus than P. olivaceusin the following biometries: higher ratios of body length to body height (56.3%), head length to snout length (20.6%), and head length to upper jaw length (34.2%). They also showed some significant biometric characteristics similar to P. stellatus, such as ratios of predorsal length (10.5%), prepectoral length (32.2%), preventral length (29.8%), and preanal length (28.0%) to body length. The hybrids had black spots on the dark brownish-green area near the eyes, and they lacked the small bony tubercles that area characteristic of Platichthys stellatus. The hybrids had unique bands: 6~20 bands on the dorsal fin and 5~10 bands on the anal fin that gradually lost their coloration towards the fin margins. The number of fin rays were 60~66 for dorsal fin, 40~51 for anal fin, 18~21 for caudal fin, and 11~12 for pectoral fin. The gills of the hybrids contained 13~18 gill rakers and 73~98 gill filaments. The vertebrae of the hybrids numbered 34~37, with 2~3 vertebrae fused from the start of the caudal vertebrae.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.263-274
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• 2015

Change in morphological and biological characteristics of Japanese eel, Anguilla japonica, by maturation were determined by examination of 182 individuals collected in Korea waters from September to December 2014. Eels were classified into four stages based on the silvering index. The proportion of silver eels collected from streams and estuaries (34.6%) was higher than that from the freshwater reservoirs (3.8%). The sex ratio between female and male was 1:0.11 (n=182). Mean total length and weight were positively related to the silvering process. The ratios of head and pectoral lengths to total length and the ratio of horizontal and vertical orbital diameters to head length were significantly different between the maturation stages. However the ratio of pre-dorsal and pre-anal lengths to total length were not significantly different between the maturation stages. The gonado-somatic index was the single character that could identify the whole four stages among the indices examined: gonado-somatic index (GSI), condition factor (K), gut index (GI) and eye index (EI) but hepato-somatic index (HSI). One pseudo-silver eel collected. looked like a late silver eel in the S2 stage according to its external body color and morphology, but most of other characteristics suggested that it might be in Y1 (yellow eel) or Y2 stage (late yellow eel).

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.118-123
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• 2000

Heritabilities of growth traits, and phenotypic and genetic correlations for rearing masu salmon Oncorhynchus masou in adult stage were described. Genetic parameters were estimated for total length, body weight, and head length of masu salmon at 19 and 23 months of age. The heritabilities of growth traits estimated for sire component at 19 months of age was 0.22 in each trait in 1995, and ranged from 0.19 to 0.36 at 23 months of age in 1996. Phenotypic and genetic correlations were high among growth traits(0.85~0.98, 0.67~1.26, respectively). Family selection or that combined with individual selection is proposed to improve growth of masu salmon.

• Journal of Aquaculture
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• v.10 no.1
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• pp.49-54
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• 1997

Characteristics of sex ratio and morphometric traits of induced allotriploid between female rainbow trout, Oncorhynchus mykiss and male cherry salmon, O. masou were performed. Sex ratios in both rainbow trout and cherry salmon were equally 1:1, while hybrid and allotriploid revealed higher proportion of male offspring (p<0.01). Body trait measurements of allotriploid in head hight/head length, length of dorsal fin base/body length and length of pectoral fin/body length were intermediate to their parental species, while in length of upper jaw/head length, allotriploid much more resembled that of rainbow trout. These facts proved that allotriploidization improved characters in sex ratio and morphometric traits compared to those o their parental species.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.241-245
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• 1990

In order to resolve the taxonomic contusion of Acheilognathus limbata from Korea, 17 morphological characters, egg form and cleavage part of A. limbata from Japan and Korea were ompared. These two groups are overlapping each other in morphometric characters mostly, but two characters of snout length and interarbital width percent in head length are distinguished between them. Moreover the Korean and the Japanese specimens are significantly different from each other based on the egg form and, cleavage part of egg. These results indicate that A. limbata from Korea and from Japan are homonyms. So we consider that the target specimens from Korea should be treated Acheifognathus sp. rather than Acheilognathus limbata until further informations are available.

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.46-60
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• 2011

A taxonomic review of 6 genera and 10 species in the family Ophichthidae was carried out based on specimens from the adjacent waters of Korea. The number of vertebrae distinguished the species of each genus: Ophisurus macrorhynchos (201~209), Ophichthus rotundus (178~183), Pisodonophis zophistius (179~182), P. cancrivorus (153~164), Echelus uropterus (152~158), Muraenichthys gymnopterus (155~156), Ophichthus evermanni (150~154), Brachysomophis porphyreus (137~148), Ophichthus urolophus (135~138), Ophichthus asakusae (124~134). Snout length in head length distinguished the 6 genera: Ophisurus (27.2~31.2), Echelus (18.0~27.7), Ophichthus (12.3~21.5), Pisodonophis (16.5~20.8), Muraenichthys (11.4~11.9), Brachysomophis (9.1~9.4). A key to the 6 genera and 10 species of the family Ophichthidae from the adjacent waters of Korea is provided.