• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.218-223
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• 2017

Using both light and scanning electron microscopies, it was investigated on the visual cells as well as the eyes of Macropodus ocellatus (Pisces, Osphronemidae). This species had a circular lens and yellowish cornea. The eyes had $3.5{\pm}0.2mm$ which is $31.1{\pm}3.0%$ in a percentage of eye diameter relative to head length. The retina ($158.2{\pm}10.6{\mu}m$) was built of several layers, including the visual cell layer which consists of three types of cells: single cons ($27.8{\pm}1.6{\mu}m$) and equal double cone ($33.9{\pm}3.7{\mu}m$), and large rods ($57.3{\pm}1.3{\mu}m$). The visual cell layer then was classified into the correct pattern. All visual cells were clearly distinguished from two parts (inner and outer segments). The elongated rod cells were extend to the bottom of the retinal pigment epithelium. In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles. The M. ocellatus single and double cones appearance form a flower-petal arrangement, which is a regular mosaic pattern that contains quadrilateral units by four double cones surrounding a single cone.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.77-86
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• 1998

The ichthyofauna and the structure of fish community were surveyed from August 1995 to October 1997 at twenty one stations in the Wicheon river which is a first tributary located at the middle reach of the Nakdong river system. During the surveyed period, 40 species belonging to ten families were collected. Of them cyprinid fish occupied 65.0% (26 species) and cobitid fish 12.5% (5 species). Sixteen species (40.0%) were known as Korean endemic species. Dominant species were Zacco temmincki (15.35%), Zacco platypus (14.12%), and Squalidus gracilis majimae (11.32%). Rare species which occupied less than 0.1% of total individuals were Cyprinus carpio, Culter brevicauda, Misgurnus mizoiepis, Cobitis rotundicaudata, Leiocassis ussuriensis, Silurus asotus, Macropodus chinensis, and Channa argus. A tendancy were shown in regional distribution that Moroco oxycephalus dominated in upper stream, Zacco temmincki, Squalidus gracilis majimae, and Niwaella multifasciata in mid - upper stream, acheilognathid fishes and Zacco temmincki in mid - lower stream, and Zacco platypus and microphysogobioid fishes in lower stream. St. 9, 10, and 11 which located in mid - reach of main stream and St. 17, 18 and 19 which located in mid - reach of the Ssanggye stream had the most stable and diverse community structure.