• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.1-7
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• 2022

A larva of the deep-sea angler fish, Himantolophus groenlandicus (2.2 mm BL), identified based on the complete mitochondrial DNA sequence, was collected at the surface of the western North Pacific. The postflexion stage larva had a round body, small teeth, incipient dorsal fin rays, eyes slightly recessed in the lower part, and melanophores on the gills and parietal and dorsal regions. These morphological features differ from a description of a larva reported as the same species with similar size (2.1 mm BL). The genetic and morphological information of our specimen should be useful for identifying larval H. groenlandicus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.189-194
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• 2022

Unidentified postflexion larva (18.57 mm in standard length, SL), belonging to the family Synodontidae was collected from Jeju Island, Korea, in November 2019. Molecular analysis revealed that the unidentified larva was identical to Synodus kaianus adults in mtDNA cytochrome c oxidase subunit I region (Kimura-2-parameter distance, d= 0.006), and was different from the close species S. macrops (d=0.220). The postflexion larva of S. kaianus has the following morphological features: regularly distributed seven peritoneal pigment spots along the alimentary canal; and, intensively distributed stellate melanophores at the middle of the base of caudal fin and behind the last anal fin ray. The postflexion larva of S. kaianus differed from that of S. macrops in snout length and size of peritoneal pigment spots. This is the first record of S. kaianus in Korea, and we suggest the Korean name "Ka-i-ya-kkoch-dong-myeol" for S. kaianus, according to Lee et al. (1999).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.909-915
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• 2023

A specimen of longarm mullet Moolgarda cunnesius (Valenciennes, 1836) belonging to the family Mugilidae was collected from Yerae-dong, Seogwipo-si, Jeju-do Island, Korea, on July 19, 2023, using a hand net. The specimen was identified as Moolgarda cunnesius based on its morphological traits, including pectoral fin reaching the third or fourth spine of the first dorsal fin, anal fin higher than the first and second dorsal fin, two dorsal and caudal fin membranes with small melanophores, and a slightly convex interorbital region. Furthermore, molecular analysis, specifically comparison of the 623 base pairs of mitochondrial DNA COI sequences, confirmed that our specimen perfectly matched M. cunnesius. It is well known that the species is widely distributed in the Indo-West Pacific Ocean, including the Red Sea, Taiwan, and northern Australia, and this study shows that it also inhabits the Jeju-do Island, Korea. Additionally, we propose a new Korean name 'gin-pal-sung-eo' for this species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.153-168
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• 2024

Morphological and skeletal development in the cultured threeline grunt Parapristipoma trilineatum was studied from 1.96 to 61.39 mm notochord length (NL) or standard length (SL) specimens (n=360). After two days post-hatching (dph, 2.13 mm NL), the mouth opened, and melanophores formed in the eyes and egg yolk were absorbed. Oli globules were absorbed at 3 dph (2.71 mm NL). The total number of fin rays reached that of adults at 28 dph (10.58 mm SL). During skeletal development, the premaxillaray, dentary, opercle, preopercle, and cleithrum first began to ossify at 6 dph (3.51 mm NL). Ossification of all skeletal elements was completed at 28 dph (14.57 mm SL). The vertebrae began to ossify at 17 dph (5.63 mm SL) and were completed at 28 dph (8.48 mm SL), progressing from cranium to caudal bone. The centrum ossified from the dorsal to ventral direction. Vertebral fusion and separation were found to be common skeletal abnormalities.

• Development and Reproduction
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• v.18 no.2
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• pp.79-87
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• 2014

In Pleuronectiformes, blind-side malpigmentation (hypermelanosis) is common in cultured flatfishes, and is economically important. To understand the mechanism of blind-side hypermelanosis in flatfishes, we examined when the malpigmentation initially occurred, and studied how the symptoms proceeded during early development of the starry flounder, Platichthys stellatus. To assess quantitative pattern changes of blind-side skin, we observed morphological development of the whole body from 22 (total length [TL] $10.0{\pm}0.2$ mm and body weight [BW] $8.8{\pm}0.57$ mg) to 110 days (TL $23.4{\pm}0.7$ mm, BW $193.6{\pm}23.3$ mg) after hatching (DAH), and also examined the malpigmented area rate of blind-side skin and the malpigmented fish ratios. The experimental animals were reared in fiberglass-reinforced plastic (FRP) tanks in water at a temperature of $18.9{\pm}1.9^{\circ}C$ and salinity of $32.6{\pm}0.6$ psu and were fed with rotifer and Artemia nauplii from 22 to 48 DAH, and with A. nauplii and commercial feed from 49 to 110 DAH. As results, the first staining patch seen by the naked eye was observed around the area between the anus and pelvic fin or caudal edge of the trunk at 80 DAH (TL $20.6{\pm}0.5$ mm, BW $112.5{\pm}8.8$ mg). The pigmented area and the pigmented fish ratios were significantly increased from 80 to 110 DAH. These results indicated that malpigmentation on the blind side of starry flounder was initially observed at about 2 cm in length and 100 mg in weight, and the pigmented domain on the blind-side skin was continually broadened by the differentiation of pigmented cells (melanophores and xanthophores) with growth.

• Development and Reproduction
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• v.17 no.4
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• pp.369-377
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• 2013

The fertilized eggs of E. septemfasciatus are spherical and transparent with buoyancy at 790 to $890{\mu}m$ (average $821.8{\pm}2.0{\mu}m$) in diameter with 170 to $230{\mu}m$ oil globules (average $192.9{\pm}0.93{\mu}m$). Hatching began approximately 46 and 35 hours after fertilization at $22.0^{\circ}C$ and $25.0^{\circ}C$ water temperature, respectively. The average total length of newly hatched larvae was $1.75{\pm}0.03mm$. Most of the yolk and oil globules were absorbed within 3 to 4 days after hatching. The larvae reached 2.48 to 2.72 mm in total length, and their mouths and anuses opened at 3 to 4 days after hatching. In this time, the mouth diameters of the larvae were 0.209 to 0.238 mm. The larvae reached 3.24 to 4.15 mm in total length at 11 to 17 days after hatching, and began to metamorphose at the time the second dorsal and pelvic spines appeared and elongated. The abdominal cavity was densely lined with melanophores. The larvae reached 5.12 mm in total length at 24 days after hatching.

• Development and Reproduction
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• v.21 no.3
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• pp.287-295
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• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.395-400
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• 1983

Rock trout, Agrammus agrammus(Temminck et Schlegel) is commonly found at the coast of Korean waters. Mature adult of the rock trout were collected at the shore of Dongbaeksom in Pusan during the period from Nov. 18 to Nov. 25, 1983 through know the early developmental characters. The authors carried out the artificial insemination in the laboratory on Nov. 24, 1982, and roared the eggs and the hatched larvae. The eggs of this species are demersal and adhesive, and their diameter were varied within 1.92-2.14mm. The color of yolk is light blue in the early developmental stage, and then turned to orange before hatching out. The yolk contained numerous tiny oil globules. Hatchig toot plnace in ca. 463 hours after insemination at $11.8-17.9^{\circ}C$ of water temperature. The newly hatched larvae were elongate in share and 6.55-8.20 mm in total length with 12+26=48 myomers. Many branched melanophores were distributed on the supra-orbital, dorsal double body contour, and peritoneal, and also under the notochord of the tail.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.279-284
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• 2010

Four leptocephali (TL 109.8~129.7 mm) of the family Ophichthidae, collected from Sangju in the South Sea of Korea, were identified using morphological and molecular methods. Our four leptocephali were similar to Ophichthus sp. based on morphological characters: the melanophores present in series of eight gut swellings; total myomeres 144~151; body depth in total length less than 10%; eight or nine black horizontal bands present from anus to caudal fin base. On the other hand, our four leptocephali were identified to Pisodonophis sp. based on 826 base pairs of 12S rRNA gene nucleotide sequences. Our results showed that morphology-based identification did not agree with molecular identification, indicating difficulty in differentiating morphologically between Ophichthus and Pisodonophis leptocephali. We, herein, firstly describe morphological characteristics of Pisodonophis sp. leptocephali from Korea.

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.217-224
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• 2011

The seven leptocephali (14.6~68.0 mm in total length) of the family Ophichthidae, from the East Sea of Korea, were identified using 12S rRNA 861-bp sequences and their morphological development were described. Our seven leptocephali were identified to Echelus uropterus based on genetic distance (d=0.000) being well consistent with that of adult E. uropterus. Our seven leptocephali of E. uropterus are characterized by morphological combinations: caudal fin present; the melanophores present in series of nine gut swellings; total myomeres 154~158; body depth in total length less than 10%; eight black horizontal bands present from anus to caudal fin base. Our morphological and molecular results suggest that E. uropterus may be an intermediate group between subfamily Ophichthinae and Myrophinae.