• Korean Journal of Ichthyology
• /
• v.17 no.3
• /
• pp.217-220
• /
• 2005

Three specimens of leptocephalus larvae (33.4~35.2 mm in SL) were collected from the southern coast of Jeju Island, Korea, by an aquatic lamp on August 14, 2004. These larvae were identified as Elops hawaiensis because of their having a forked caudal fin, a smaller anal fin than dorsal fin, and anal-fin position posterior to dorsal fin.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.6
• /
• pp.1209-1216
• /
• 2014

This feeding experiment was conducted to investigate the effects of slurry type diet on growth performance and survival rate of growing leptocephalus, eel larva. We need to find new materials of diets for rearing eel larvae. Test diets were formulated with the eggs of the shark, fish soluble concentrate, soybean peptide and fish protein hydrolysate. Fish (average length 6 mm) were fed 3 slurry type diet(A, B and C) based on shark egg for 5 times per day. During feeding experiment, survival rates were significantly different among 3 slurry type diets. Total protein, lipid, moisture, ash and free amino acids contents were analyzed for slurry type diets. Leptocephalus fed the C slurry type diet was grown up to $38.0{\pm}9mm$ at 150 days. But all leptocephalus fed B slurry type diet were died at 100 days, reaching $16.4{\pm}8mm$. This results suggest that basic information for diet development of eel leptocephalus.

• Journal of Marine Life Science
• /
• v.8 no.2
• /
• pp.128-135
• /
• 2023

The present study was tried to identify whether the eel's larva was close to a conger (Conger myriaster), a pipe conger (Muraenesox cinereus) or four species of Anguilla. Experimental fishes were collected by set net in the gulf of enggang, Namhae, Korea from May to June. Their morphological characteristics were compared with adult fishes of a conger, a pipe conger and four species of Anguilla. For genetic classification, DNA was isolated and amplified by using 12S rRNA and 16S rRNA primer set. The PCR products were direct sequencing in both directions. The nucleotide sequences were analyzed using softwares. As results of morphological measurement on eel's larva, the percentages of head length and preanal length against total length were similar with a conger. Based on the nucleotide sequences, the phylogenetic tree also revealed a close relationship to a conger. Therefore, eel's larva, caught in Namhae from May to June, was identified into a conger's larva.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.4
• /
• pp.551-556
• /
• 2020

Eel Anguilla japonica is an economically important inland culture fish species in East Asian countries, particularly in Korea, Japan, China, and Taiwan. In this study, the effects of feeding frequency on larval growth and survival rate were investigated. Eel larvae (average length, 6 mm) were fed a slurry-type diet containing shark eggs three, five, seven, or nine times per day. Survival rates differed significantly among the four experimental groups. Feeding frequencies of at least five and seven times a day were required until 15 and 30 days after hatching, respectively, to maintain an acceptable survival rate. Leptocephalus growth improved with increased feeding frequency until 15 days after hatching. The results suggest that providing an opportunity for early food intake enhances eel survival and growth in the early leptocephalus stage.

• Journal of Life Science
• /
• v.23 no.10
• /
• pp.1288-1294
• /
• 2013

Knowledge of morphological changes in eel larvae is very important for artificial rearing of eel larvae. In this study, we investigated the morphological structure of the head region and histological changes of the eye retina in artificially reared larvae at various stages and in glass eel just after metamorphosis. Structural changes were observed in the upper jaw (maxilla) and the lower jaw (mandible) after 100 dah (day after hatchery) and after metamorphosis. Teeth had degenerated by the time of completion of metamorphosis. Major histological changes observed in the eye retina were the formation of the outer plexiform layer and the outer nuclear layer from 100 dah larva and a change in the rod cell layer after metamorphosis. The cornea was not observed at 10 dah in the eel larva. More information is needed on the early developmental stages of eel larvae to enable mass production of glass eels. The results obtained in the present research will be useful when developing novel rearing programs for eel larvae.