• Animal cells and systems
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• v.12 no.4
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• pp.297-304
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• 2008

Morphology and distribution of the minute tubercles projected on the skin surface of larvae with its development were observed in the Korean bitterling, Acheilognathus somjinensis. The minute tubercles appeared to be two distinct morphologies, hemispheric or scaly and vestigial structures. Just after hatching, the epidermis of the larvae consists of a thin single cell layer having smaller basophilic flat or round-flattened basal cells. As the larvae grow, the epidermis contains more small flat cells and large epidermal cells which are round and hemispheric, or scaleshaped, called minute tubercles. They are distributed over the anterior part and most part of yolk sac, posterior region of yolk sac and the body region. Vestigial epidermal cells, another minute tubercle, occur only in the caudal fin-fold region, which they are shrunken and flattened, causing the cell boundary to be unclear. They increase in number and height from just to 5 days after hatching, but they become reduced as the larvae develop gradually. The required time for those disappearance was different each by regional body: at day 20 after hatching in the anteriormost part of yolk sac, and day 11 after hatching in the posterior part of yolk sac and the body, and day 21 after hatching in two regions such most part of the yolk sac and the caudal finfold regions.

• Korean Journal of Ichthyology
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• v.17 no.2
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• pp.105-111
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• 2005

Most of the eggs and (or) pre-larvae of Acheilognathus signifer were observed from the gills of Unio douglasiae sinuolatus, 30~45 mm in the shell length, that is the host mussel of A. signifer. There was no selectivity in proportion to mussel size at the range observed. One to seven individual eggs and (or) pre-larvae were found in the mussels, with a mean of 2.5 individuals, and the rate of possessing one egg and (or) pre-larva was 50.0%. When the prelarva of A. signifer acquired swimming ability inside the mussel, it moved into the suprabranchial chamber. It was estimated that the growth period was 4~6 weeks. The minute tubercles of the pre-larvae were observed immediately after hatching. Absorption of the minute tubercles was observed starting the 7 th day, with most of tubercles absorbed 13 days after hatching and completed 20 days after the yolk was entirely absorbed.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.170-177
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• 2006

Morphology and distribution of the minute tubercles projected on the skin surface of larvae with its development was observed in the Korean bitterling, Acheilognathus koreensis, known as an endemic freshwater fish. The epidermis of the larvae consisted of a thin single layer, having smaller basophilic flat or round-flattened basal cells. In between the single cell layer, two or three layers were added and they consisted mainly of large epidermal cells just above basal cells. These large unicellular epidermal cells were mainly scale-shaped and rarely cone-shaped, and do not give any histochemical tests for mucosubstances. They were present in anterior region and most region of yolk sac. Whereas, vestigial epidermal cells were distributed in the body region and the caudal fin-fold region. These two kinds of epidermal cells, called minute tubercles, increased in number and height from Just to 8 days after hatching, but as the larvae develop gradually, they became to reduce. At 31days after hatching of free swimming stage and absolute absorption stage of the yolk sac, the minute tubercles did not exist on the whole skin of the larvae.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.193-198
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• 2005

This study investigated the characteristics of the eggs and yolk sac larvae of Korean striped bitterling, Acheilognathus yamatsutae, spawned and grown In mussels. The number of eggs in the ovary was small ($358{\pm}108$ SD). The eggs were oval and large, and the formation of the perivitelline space was narrow. The eggs were hatched at only 41 hours after fertilization but the hatched larvae were underdeveloped. The development of yolk projection and minute tubercles on the skin surface was notable, along with the vividly moving tail in the hatched larvae. The yolk projection and minute tubercles were disappeared upon enhancement of the motor ability of the larvae was enhanced. The formation of eyes and body pigments of the larvae was relatively delayed in comparison with that of other cyprinid larvae. After completely consuming the yolks the larvae escaped from the mussel for free swimming and exogenous feeding.

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.510-511
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• 2004

A terrestrial cave snail (Gastropoda: Subulinidae), Sinistras chois n. gen., n. sp., from the Gungi-cave in Jeju Island, South Korea represents a monotypic genus, and is proposed as a new genus in the family Subulinidae. Diagnostic features of the genus include a sinistral shell, that has a minute-sized, elongate conic-shaped, apical microsculpture with low tubercles. The chromosome number and karyotype are 2n=56 and 8M+15SM+5ST, respectively.

• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.77-87
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• 1990

The development of eggs and larvae, and minute tubercles on the skin surface of the larvae in Acheilognathus lanceolatus (=Acheilognathus intermedia intermedia) from Korea were observed. The ripe eggs of A. lanceolatus from Korea were nearly spindly. The shape was distinguishable from that of Japan. And then the embryonic development of this specimen from Korea was faster than that from Japan. As regards larval development and morphology and distribution of the minute tubercles, however, A. lanceolatus in both Korea and Japan were same except for the mentioned above two characters. These findings suggested that the two formes should be separated at subspecies level.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.73-82
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• 1989

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of the larval Acanthorthodeus asmussi from Korea were observed in the laboratory. The egg was nearly ovoid-shaped. The number of egg averaged 195 per an oviposition. The morphological character of larval development was relatively similar to those of Acheilognathus tabira tabira, A. tabira subsp. (a), A. yamatsutae, A. moriokae, A. cyanostigma and A. rhombeus. The larvae of this species had many scale-like tubercles ellipsoided in a diagonal cross section on the skin surface of the body. And also this species moved like incessant wiggly movement pattern as that of fly maggot duing the larval development. As regards the tubercles and larval movement pattern, the larvae of A. asmussi shared similar characters with those of Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typos. Hence A. asmussi may be closely related to these species. The latter three species are autumn-spawning bitterlings and the larval development always retard in a certain stage, while A. asmussi is a spring-summer spawning species and the larval development never retards. Judging from these facts, it should be considered that there are close relations in evolutionary trend between the two spawning species.

• Korean Journal of Ichthyology
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• v.6 no.1
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• pp.39-50
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• 1994

Spawning of the bitterling, Acheilognathus yamatsutae into the mussel was studied from 1990 to 1992 in Lake Uiam, Korea. This fish preferred to spawn in certain mussel species such as Unio douglasiae, U. douglasiae sinuolatus, Lamprotula gottsehei and Anodonta arcaeformis flavotincta in order of preference. Within the same species of mussel, they preferred the larger size. Eggs and larvae were commonly located in the inner demibranch of mussels. Average number of eggs or larvae per mussel was 3.6(ranged from 1 to 35). The eggs of the bitterling were hatched out within 41 hours when water temperature remained over $20^{\circ}C$ and the larvae already possessed minute tubercles on the skin and yolk projections to prevent themselves being washed out from mussels.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.169-181
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• 1990

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of larval Acantlaorhodeus gracilis from Korea were observed. They spawned from late March through the middle of June. A fish spawned at least 5 times and the number of eggs averaged 304 per oviposition. Unfertilized eggs are nearly ovoid-shaped(mean$\pm$SD=$2.09{\pm}0.04\;mm$ in length with range of 2.05 to 2.13 mm and mean$\pm$SD=$1.26{\pm}0.02\;mm$ in breadth with range of 1.24 to 1.30 mm measured for the 50 eggs) and opaque yellow color. The tip of egg membrane at the animal pole side swelled and formed a few hilly projections. The shape of the eggs was just like a loquat. Most of embryos began to hatch out in thirty-eight hours after insemination at $22{\pm}1^{\circ}C$ in water temperature. As regards the morphological characters of the eggs and larval development, Acan. gracilis was similar to Acan. asmussi, Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typus. The larvae of this species is unique particularly in the following two characters, i.e., 1) scale-like tubercles ellipsoided in a diagonal cross section on the whole body and 2) incessant wiggly movement pattern as that of fly maggot, with the larvae of the above mentioned species. These characters seem to reflect the phylogenetic relationships among acheilognathine fishes. On the other hand, this species and Acan. asmussi are spring-summer spawning bitterlings. And also these species never retard the larval growth in such larval stage as the duration from Stage B to Stage D.