• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.3
• /
• pp.255-263
• /
• 2014

We investigated the reproductive characteristics of Lycodes tanakae in the coastal waters of the middle East Sea to elucidate the species' population structure. We investigated Lycodes tanakae maturation and spawning based on samples collected by Danish seine and gill nets from January 2012 to December 2013. We analyzed monthly changes in maturity stage, gonadosomatic index (GSI), egg diameter, fecundity, and total length at 50% group maturity. The spawning period was December to February, while fecundity ranged from 1,677 eggs at 57.3 cm (total length;TL) to 6,445 eggs at 75.7 cm. The relationship between TL and fecundity (F) was $F_e=6E-05TL^{3.127}$ ($R^2$ = 0.516), and F increased with increasing TL. We estimated the TL at 50% group maturity as 60.4 cm for females and 59.8 cm for males. This study is the first report of Lycodes tanakae reproductive characteristics in the coastal waters of the middle East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.6
• /
• pp.843-850
• /
• 2013

The feeding habits of Lycodes tanakae Eelpout were studied with 722 specimens collected from March 2011 to December 2012 in the coastal waters of the middle East Sea. The main prey of L. tanakae were fish, molluscs and arthropods. Nevertheless annelida, echinodermata and others were found in small amounts in the stomach contents. The L. tanakae stomach was empty of contents in 50.9% of specimens. While smaller size specimens of L. tanakae (less than 40 cm) fed mainly on euphausiids and amphipods, the larger specimens (more than 40 cm) fed on the fish Allolepis hollandi and Icelus cataphractus, and the molluscs Berryteuthis magister and Watasenia scintillans. The main prey items of L. tanakae varied seasonally. The fish Lycodes nakamurai was the dominat prey from November to January during its spawning season. Euphausiids and amphipods of the arthropods were the dominant prey from February to April. The molluscs Berryteuthis magister and Watasenia scintillans were the dominant prey from May to September. The diversity index (H') of diets showed variations by length class and month; the highest values were 2.61 in the length class of 51-55 cm, and the monthly highest were 2.68 in September with 23 species and 2.65 in November with 18 species. The highest dominance index (D') of diets was 0.57 in the length class of 31-35 cm, and the monthly highest was 0.71 in February. Cluster analysis divided prey groups into four groups by length class and three groups by monthly prey items. The gonad index gradually increased during the process of maturation while, contrary, stomach content index decreased during this period.

• Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.99-105
• /
• 2012

The biochemical composition of muscle from three deep-sea animals, Tanaka's eelpout Lycodes tanakae magistrate armhook squid Berryteuthis magister, and ocean sunfish Mola mola caught in the East sea in South Korea was determined. The moisture (81.4-93.8 g/100 g), crude protein (5.0-15.6 g/100 g), crude lipid (0.1-1.5 g/100 g), and ash (1.0-1.1 g/100 g) contents of the two fishes were analyzed. The proximate composition of magistrate armhook squid was: moisture 84.0 g/100 g, crude protein 12.4 g/100 g, crude lipid 0.7 g/100 g, and ash 1.5 g/100 g. There was little difference in the proximate compositions of the three animals. The total amino acid contents of Tanaka's eelpout, magistrate armhook squid, and ocean sunfish were 14.64, 10.75, 3.10-9.95 g/100 g, respectively. High levels of glutamic acid, aspartic acid, lysine, leucine, and arginine were found, while low levels of histidine, glycine, and cysteine were detected in the animals. A survey of the free amino acid contents of the animals revealed large amounts of alanine and glycine. Significant differences were found in the fatty acid composition among the three species. Specially, different saturated fatty acids (17.14-40.49%) such as C16:0, and C18:0, monounsaturated fatty acids (19.19-46.88%) such as C16:1, and C18:1, and polyunsaturated fatty acids (35.41-57.08%) such as EPA, and DHA was identified. Our results suggest that each of these deep sea animals possesses nutritional value and should be considered as a foodstuff.