• Animal cells and systems
• /
• v.7 no.4
• /
• pp.331-335
• /
• 2003

Vertebrates with different habitats have different proportions of visual cells, with the rod cells responding to scotopic vision and the cone cells responding to photopic and color vision in their retinas. The present work studied whether the kinds and arrangement patterns of the cone cells and interlocking morphology of the lens were related to the kind of preys and habitats in the genus Zacco. The retinas were observed by a light microscopy using H-E staining method and the interlocking formula of the lens fibers were investigated by a scanning electron microscopy. The interlocking formula of the lens fibers of Z. temmincki is an ' anchor and socket ' connection, and that of Z. platypus is a ' ball and socket ' connection. The cone cells of Z. platypus and Z. temmincki constituted compacted mosaic patterns of row type. Away from the center, the double and single cone cells gradually increased in diameter. Zacco temmincki had identical double cone cells and Z. platypus had non-identical double and single cone cells. The eyes of Z. temminckifeeding on a moving aquatic insects in relative limpid water and swift current of mid and upper stream have better resolution than that of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water of mid stream.

• Applied Microscopy
• /
• v.43 no.1
• /
• pp.14-20
• /
• 2013

The leopard danio, Danio rerio var. frankei is a spotted color morph of the zebrafish, Danio rerio caused by a pigment mutation. The structural differences of fertilized egg and egg envelope are poorly documented. To clarify this, we compared the fertilized egg morphology and ultrastructures of surface structures, the micropyle and the cross section of fertilized egg envelopes of zebrafish and leopard danio, variation species of zebrafish using a light and electron microscopes. Although the fertilized egg sizes were different, the external shapes of the fertilized eggs of two species couldn't be differentiated under the light microscope. The characteristics of fertilized eggs, such as a spherical shape, a non-adhesive quality and a large perivitelline space, were shown to be related to spawning habit. In ultrastructure of fertilized egg envelope, there is no morphological difference of micropyle between two species. By contrast, the ultrastructure and the numbers of knob-like structures and semihemisphere-like structures per unit area on the outer surface, and the number of lamellae of inner layer on the fertilized egg envelope section displayed definite species specificity. Collectively, our data indicate that the ultrastructure of fertilized egg envelope in the zebrafish could be differentiated by species variation.

• Animal Systematics, Evolution and Diversity
• /
• v.3 no.1
• /
• pp.41-50
• /
• 1987

The osteological characters of Aphyocypris chinensis of subfamily Leuciscinae were examined and the systematic position of this species is discussed through comparison with other species of subfamilies Leucisicinae and Cultrinae. Numbers of the dorsal an danal fin ray, having no symphyseal knob and barbels and separation between dermosphenotic and supraorbital, are in acord with those of subfamily Leuciscine, and the abdominal keel and trigemino-facial nerve foramen of the prootic are more closely related with those of subfamily Cultrinae. But several diagnostic characters detected only in this species are as follows ; 4 infraorbitals, the shape of ethmoid, 5-6 hypurals, the broad orbital width, having no extrascapular, incomplete lateral line and considerable small size.

• Korean Journal of Ichthyology
• /
• v.13 no.4
• /
• pp.230-236
• /
• 2001

Feeding habits of Gobiobotia brevibarba were investigated at Hongcheon River of Bangokri, Seomyon, Hongcheongun, Kangwondo from January to December, 2000. G. brevibarba was a carnivore and consumed mainly Ephemeroptera, Tricoptera and Diptera. Small quantities of Plecoptera and Coleoptera were included as a minor food items. The species showed ontogenetic changes in feeding habits. Individuals of small size (21~50 mm SL) fed mainly on small prey organisms such as Diptera and Ephemeroptera. However, larger Tricoptera were heavily selected with increasing fish size. The relative proportion of these food items changed with season. The prey selection indices for Ephemeroptera were positively selected in spring, summer and autumn, and negatively selected in winter, Diptera were positively selected in March, October and November.

• Korean Journal of Ichthyology
• /
• v.24 no.4
• /
• pp.253-262
• /
• 2012

A skeletal system of Coreoleuciscus splendidus from Seomjin and Mankyeong Rivers is described and figured in detail. The osteological characteristics are as follow: preorbital area elongated; eight proximal radials on the anal fin; 1st basibranchial bone with a bottle gourd shape; two types of pharynegeal teeth; intercalarium's ascending process absent and rib 4 broad greatly. Meanwhile, the number of actinost and the length of external process and internal process on the pelvic girdle are variable with individuals. These characteristics are shown in the two population. The epural on the caudal skeleton, however, has two types only in C. splendidus of Mankyeong River.

• Korean Journal of Ichthyology
• /
• v.17 no.2
• /
• pp.123-130
• /
• 2005

The ichthyofauna of Lake Cheongpyeong was investigated from April 2003 to November 2004. During the surveyed period 31 species belonging to nine families were collected. Dominant species in numbers was Hemibarbus labeo (relative abundance: 29.9%), subdominant was Acanthorhodeus gracilis (22.8%). Erythroculter erythropterus (14.6%) and Cyprinus auratus (6.3%) were also numerous. There were nine Korean endemic species belonging to three families, including Acheilgnathus yamatsutae. We need close observation on population fluctuations of Micropterus salmoides, an exotic carnivorous fish from North America, and Hemibarbus labeo and Erythroculter erythropterus, the dominant species by biomass in Lake Cheongpyeong.

• Korean Journal of Ichthyology
• /
• v.20 no.3
• /
• pp.163-166
• /
• 2008

The spermatozoal ultrastructure of Acheilognathus yamatsutae was studied using transmission electron microscopy. The mature spermatozoa are similar to those of other cyprinids as follows: a spherical nucleus with a shallow nuclear fossa, a short midpiece containing mitochondria and a long flagellum. However, there are some differences from other cyprinids in the orientation and position of the centrioles, the number of mitochondria, and the structure of vesicles. The position of the proximal centriole was of two types: one located on the side of nucleus decline, the other situated on the opposite side.

• Korean Journal of Ecology and Environment
• /
• v.40 no.4
• /
• pp.546-552
• /
• 2007

The objectives of this study were to analyze fish compositions, based on trophic guilds and tolerance guilds and determine community characteristics structure at five sampling sites of Yeongsan Lake during July 2006-May 2007. Total number of species sampled was 30 species and the number was 1350. Cyprinidae (77%) and Centrarchidae (15.7%) dominated the community and then followed by Cobitidae(2.7%), Gobiidae(2.4%), Mugilidae (0.5%), and others (0.1%). The relative abundance of tolerant and omnivore species at all sites was 63% and 77% of the total, respectively, suggesting an ecological degradations in the Lake. Exotics species such as large mouth bass (Micropterus salmoides), which is a top-carnivore in the water distributed at all sampling sites, implying that ecological disturbance was severe based on previous reference of US EPA (1991). Also, we found external anomalies such as external deformities, bleeding and tumors and not found migratory fish. Analysis of fish community structure showed that species diversity index and richness index was the highest in Site 1 and the dominance index was the highest in Site 2. In this study, high proportions of tolerant species and omnivore species, widespread exotic species, and frequent observations of abnormal fish. Such problems may be directly or indirectly associated with high nutrient enrichments and the reduced flow velocity by the dam construction. The ecosystem restoration by dam removal or removal of exotic top-carnivore fish may be one of the best strategies for better lak management.

• Korean Journal of Ichthyology
• /
• v.22 no.1
• /
• pp.49-55
• /
• 2010

Sympatric sites of type NE and NS of Zacco korean us were found in the upper reaches of many tributaries of the Nakdong and Seomjin rivers, as well as in some streams draining into the South Sea, Korea. In streams where the two types exist together, there was a tendency for individuals of NE to densely populate the upper reaches and those of NS to populate the middle reaches. A habitat-segregation phenomenon was observed in the cohabiting sites. Fishes of NE preferred rapids, whereas fishes of NS preferred slowly flowing or lentic regions. It seemed that the number of NE was proportional to the flow velocity, but NS showed an opposite trend in the cohabiting sites. On the other hand, such tendency was not found in regions where NE and NS exist separately.

• Korean Journal of Environmental Biology
• /
• v.22 no.1
• /
• pp.159-166
• /
• 2004

The effects of polychlorinated biphenyls (PCBs) on the reproduction of the oily bitterling, Acheilognathus koreensis were investigated using histological methods. The experimental fishes were exposed to 0. 3.4, 9.3 and 25.8 ${\mu}g\; L^{-1}$ PCBs fey 8 weeks. Dead fishes and abnormal behavior were not observed in control and PCBs exposure group. In compared with control group, PCBs exposure fishes showed differences of gonadal development, gonadosomatic index (GSI), hepatosomatic index (BSI), nuptial color index (NCI) and ovipositor length index (OLI). These results showed that PCBs could disrupt reproductive process in the fish.