• Journal of Aquaculture
• /
• v.8 no.1
• /
• pp.69-76
• /
• 1995

Hybrid fish were induced between olive flounder (Paralichthys olivaceus) female and spotted flounder (Verasper variegatus) male by artificial inseminations. Survival, growth and morphological changes in larval stage of hybirds were examined and compared to their parental species. Survival and growth up to 25 days after hatching of the hybrids were more similar to those of olive flounder than to those of spotted flounder (P<0.05). The ratio of yolk length to yolk width in hybrids was similar to that of female parents (P<0.05). The oil globule were resorbed within 18 days after hatching in hybrids and 14 days after hatching in olive flounder, and spotted flounder has no oil globule. These results indicated that survival, growth and morphological changes in larval stage of hybrids were similar to those of maternal olive flounder.

• Korean Journal of Ichthyology
• /
• v.34 no.2
• /
• pp.119-126
• /
• 2022

Here, we present the first morphological description of a larval Naso hexacanthus (5.2 mm in body length) from the East China Sea identified by cytochrome c oxidase subunit I (COI) barcoding. The larva had a kite-shaped body with long serrated first spine of dorsal and anal fins. There were four melanophores on the base of the anal fin, dense melanophores on the caudal peduncle, and scattered melanophores on the surface of the brain. There was one small spine on the snout and behind each eye, with serrations on the head, top of the eye, inner- and outer-preopercle, and on the lower part and side of the opercle. The morphological characteristics of larval N. hexacanthus identified by COI barcoding will be useful for species identification of larval fish.

• 한국해양학회지
• /
• v.25 no.3
• /
• pp.131-134
• /
• 1990

Estimates of larval mortality for many marine fishes are based on field collections from several consecutive ichthyoplankton surveys, assuming that the surveys have covered the entire areas of larval habitats. The oceanic environment, however, is so dynamic and complicated that planktonic forms cannot stay within a confined area for a prolonged period. This note is prepared as a more detailed explanation of the estimates of fish larval mortality in the oceanic dispersing system, as a supplement of Kim and Bang (1990).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.616-620
• /
• 2017

The feeding habits of post-larval Yatabe blenny Parablennius yatabei (2.0-9.8 mm SL) were examined on the basis of 158 individuals collected from June to October in the coastal waters of eastern Jinhae Bay, South Korea. Based on the index of relative importance (IRI), post-larval P. yatabei fed 94.4% on copepods and 5.6% on tintinnids. The preference of post-larval P. yatabei for copepods to other prey items results from ontogenetic changes. The dietary percentage of copepods increased as fish size increased and tintinnids became less important. The feeding rate of post-larval P. yatabei was consistent at all times of day.

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

• Journal of Environmental Health Sciences
• /
• v.26 no.2
• /
• pp.67-69
• /
• 2000

Yellow tails (Seriola quinqueradiata) were purchased from the Jakalchi fish market located in Busna and examined for anisakid larvae. The collected larvae were classified by their morphologicaltypes. Of the 16 yellow tails exmained, seven (43.8%) were infected with the larvae. Among 90 larvae, 81 were collected from the omentum and 9 from the muscle. Anisakids were classified into five larval types, anisakis type I (56 larvae in number, 62.2%), Contracaecum type A (8, 8.9%) and type D (7, 7.8%) and Contracaecum type C (19, 21.1%). The present study revealed that Anisakis type I was the most common among the five larval types in the yellow tails caught in the South sea of Korea peninsula.

• Journal of agricultural medicine and community health
• /
• v.26 no.2
• /
• pp.161-179
• /
• 2001

Recent patterns of infections with digenetic larval trematodes from fresh-water fish were studied in five locations of the river Taega during the period from October, 1998 to September, 2000, and compared with the data reported previously in the same river. The fish were collected using following techniques ; fishing, throwing a castnet, and using a bait of crushed oil cake in a transparent plastic bowl. Of 19 species of fish examined, eight species of encysted larvae, Clonorchis sinensis, Cyathocotyle orientalis, Centrocestus armatus, Clinostomum complanatum, Exorchis oviformis, Metagonimus species, Metacecaria hasegawai, and Metorchs orientalis, and two kinds of undetermined cyst A and C were found. The encysted larvae of Exorchis oviformis were found most frequently from 12 species of fresh-water fish, followed by Metacercaria hasegawai larvae from 9 species, the cyst of Clonorchis sinensis and Cyathocotyle orientalis from 7 species, Centrocestus armatus from 3 species, Clino- stomum complanatum from 2 species, and Metorchis orientalis from 1 species. The infection rates of fish with Clonorchis sinensis larvae were lower than those reported in 1993, whereas their intensity of infection was found lowered in 3 species, Pungtungia herz I, Saurogobio dabry i, and Squalidus jap onicus coreanus. The infection rates and intensity of 6 species of fish with Metagonimus sp ecies larvae were lower than the results in 1993, while the rates in several species of fish with Exorchis oviformis rather higher. The encysted larvae of Cyathocotyle orientalis, Metacercaria hasegawai, and Metorchis orientalis showed variations in infection rates of fish in 1993 and in the present study. However, It was impossible to compare the infection rates for the encysted larvae on the scales, fins and tail as they varied so considerably in both 1993 and 2000 surveys. This study indicate that the rate of infection with digenetic larval trematodes in fresh-water fish was still relatively high in the river Taega, and the metacercarial burden in the fish varies greatly by different fish in 1993.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.1
• /
• pp.20-24
• /
• 2000

A 7-week growth trial was conducted to investigate the effects of yeasts (Kluyveromyces fragilis and Candida utilis) with or without cell wall chemical treatment (protoplasted) in formulated diets on growth and body composition of larval ayu (Plecoglossus altivelis). Three replicate groups of ap average weighing 100 mg were fed diets containing each level ($5{\%}$) of K. fragilis, protoplasted K. fragilis, C. utilis, protoplasted C. utilis or brewer's yeast as an additive. Survival rate of fish fed the diet containing protoplasted K. fragilis, C. utilis or protoplasted C. utilis was higher than that of fish tea the control diet (P<0.05). Body weight .gain of fish fed the diet containing protoplasted K. fragilis was higher than that of fish fed the control diet (P<0.05). Crude protein and ash contents of Ssh were not significantly affected by the different dietary yeasts (P>0.05), On the other hand, crude lipid content of fish fed the diet containing K. fragilis, protoplasted K. fragilis or brewer's yeast was higher than that of fish fed the control diet (P<0.05). Amino acids composition of fish was not significantly affected by the different dietary yeasts (P>0.05), except aspartic acid. The results suggest that protoplasted K. fragilis as an additive in micro-formulated diet can improve weight gain and body quality of larval ayu.

• Korean Journal of Ichthyology
• /
• v.11 no.1
• /
• pp.72-85
• /
• 1999

A study on the larval fish assemblage around the front area was conducted in the Korea Strait in August, 1993. The front was found in the shelf break located in $35{\sim}36^{\circ}N$. A total of 125 species were found in the study area. Of these Engraulis japonicus was the most dominant species comprising 84.3% of the total fish larvae collected and followed by Maurolicus muelleri accounting for 7.7%. Gobiidae, Callionymidae and Pomacentridae showed higher frequency of occurrence. These five species can be divided into three groups. First group was comprised in the larval fish species such as E. japonicus and Callionymidae which were found in the whole study area. The second group was comprised of Gobiidae and Pomacentridae which were found in the warm area located in the southern part of the front area. The other species was M. muelleri found in the cold area located in the northern part of the front area including the front area. The assemblage, geological distribution and body length composition of the fish larvae in the Korea Strait would be mainly determined by the spawning ecology of the fishes, and the geological distribution and structure of the front which is formed in the ocean boundary between the Tsushima Current and the East Sea Cold Water.

• Journal of Aquaculture
• /
• v.11 no.3
• /
• pp.303-310
• /
• 1998

The growth and survival rate of larvae and juveniles from female rockfish (Sebastes schlegeli) broodstock in vitellogenesis by injection of 3,5,3'-triiodo-L-thyronine $T_3$ with a dose of 20 mg/kg fish wt. were examined for 30 days and compared with sham-control fish injected dime-thyl sulfoxide and control fish. Larvae were fed with rotifers for first 5 days after parturition, rotifers and Artemia nauplii for next 10 days. And then, they were fed with Artemia nauplii and commercial diet. Growth of larvae and juveniles from maternal $T_3$injection was significantly faster than that of two controls, nevertheless, the condition factor was lower than that of controls. The whole body proximate analyses indicated that there were significant effects of $T_3$ injection on protein and lipid, but no significant on moisture and ash contents. Survival rate of the fish from maternal $T_3$injection was significantly higher than that of fish from the two controls. These results indicate that thyroid hormone supplements appear to confer a distinct advantage to larval and juvenile rockfish in early, fragile development stage.