• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.179-186
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• 2011

Slime flounder, Microstomus achne is distributed in the coastal waters of Korea, west sea of Japan, BoHai, Yellow sea and East china sea. They are mainly caught by bottom trawl net during winter, from December to March. Sexual maturation of slime flounder were investigated using samples collected from commercial catch in the southern coast of Korea from November, 2006 to March, 2007. The ovary of the slime flounder is a conical bag in shape and is bilateral structure develops lengthily from the posterior of the abdomen to the end of the anal fin. The testis also is bilateral in structure, usually located in small size in the abdomen. In females, the gonadosomatic index (GSI) were peaked in January (12.46), then decreased rapidly thereafter. Female GSI values plummeted to 2.72 in March just after spawning. Male GSI values were peaked in December (2.46) before in the spawning season, then decreased slowly thereafter. The reproductive cycle would be classified into three successive developmental stages : maturation stage (November to January), ripe and spawning stage (December to February), degenerative and resting stage (February to March). Relationships between the fish sizes in total length (TL) and the number of ovarian eggs (F), the body weights (BW) and the number of ovarian eggs were indicated by the exponential equation respectively: F=29.027TL-767.8 (r$^2$=0.7686), F=0.3998BW+24.288 (r$^2$=0.8919).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.798-802
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• 1999

This study was performed to compare the effect of enrichement of rotifer and Artemia fed marine bacteria (Erythrobacter sp. S$\pi$-1) with those fed the different diets-(Super Selco, $\omega$-yeast and marine Chlorella) on the slime flounder larvae, Microstomus achne. Because the ratio of docosahexaenoic acid (DHA) to fatty acids in rotifer (dry weight $\%$) fed on Super Selco and ESP-SR including Erythrobacter sp. S$\pi$-1 was higher than that in rotifer fed marine Chlorella, the growth of the slime larvae fed the former showed better than the latter. And the ratio of DHA and highly unsaturated fatty acid (n-3 HUFA) to fatty acids in Artemia (dry weight $\%$) enriched by ESP-A including Erythrobacter sp. S$\pi$-1 were also higher than those in Artemia enriched by others or Artemia without enrichment. Larvae fed on Artemia enriched by ESP-A showed better growth and survival rate than those fed on Artemia enriched by others or Artemia without enrichment. With regard to dietary value of Erythrobacter sp. S$\pi$-1, its use could improve the quality of the live foods for the slime flounder larvae.

• Journal of Aquaculture
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• v.16 no.4
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• pp.233-239
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• 2003

Growth and activities of digestive enzymes in slime flounder (Microstomus achne) larvae were measured from hatching to near the end of larval development (day 58). Larvae reared under starved and fed conditions and the changes of acid phosphatase (ACPase) specific activity, alkaline phosphatase (ALPase) specific activity, trypsin-like enzyme activity and pepsin-like enzyme activity were described with growth and developmental stage of larvae. Total length of the starved larvae was gradually increased for 7 days post hatching and then almost unchanged. Total length of the fed larvae ranged from 5.13$\pm$0.178 mm at the day of hatching to 13.43$\pm$1.395 mm at 58 days after hatching. In starved group, dry body weight decreased from 0.l0$\pm$0.020 mg at the day of hatching to 0.05$\pm$0.012 mg at 12 days after hatching. Dry body weight of fed larvae decreased during the prelarva stage like starved group and then gradually increased. ACPase and ALPase specific activity in the starved larvae increased until all larvae died, however those activities in the fed larvae increased until 20 days and then decreased until 58 days after hatching, with no significant difference between groups. Trypsin-like enzyme activity in the starved larvae was unchanged until 3 days and then was the highest on 5 days after hatching, but not detected after completion of yolksac absorption. Those of fed larvae decreased until 3 days and sharply increased until completion of yolksac absorption. The highest trypsin-like enzyme activity in the fed group was observed at 20 days after hatching. Trypsin-like enzyme activity in the fed larvae was significantly higher than that in the starved larvae from 8 days after hatching. Pepsin-like enzyme activity was increased in 5 days after hatching in both groups. There was significant difference at 8 and 10 days after hatching between both groups. Based on above results, digestive enzyme activities were correspondingly changed to a growth and morphological transformation. Trypsin-like enzyme and pepsin-like enzyme activities are able to be a useful indices for health and growth status in larval slime flounder, because there was significant difference in digestive enzyme activities with developmental stages, growth or feed supply.

• Development and Reproduction
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• v.13 no.4
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• pp.265-270
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• 2009

The fertilized eggs were obtained from mature adult slime flounder Microstomus achne to determine the water temperature effect on egg development. The lowest water temperature for the flounder egg development was $0.4^{\circ}C$ on average. The temperature-dependent duration from fertilization to hatching ranged 86.5 to 296.7 hours at $9\sim21^{\circ}C$ with an accelerated development at higher temperature. Agreeable hatching rates, 95.8~97.0%, were obtained at $12\sim18^{\circ}C$, while lower at both extremes, 86.9% at $9^{\circ}C$ and 9.3% at $21^{\circ}C$. The highest water temperature, $24^{\circ}C$, had the life of the fertilized eggs confined within 24 hours. Water temperature was a parameter that induced an abnormal egg development: with abnormalities of 88.3% at $21^{\circ}C$, 2.1% at $9^{\circ}C$ (P<0.05), and 0.4~0.8% at $12\sim18^{\circ}C$.

• Korean journal of food and cookery science
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• v.6 no.3 s.12
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• pp.43-50
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• 1990

Distribution of amino acids and related compounds in the muscle extract of seven species of right-eye flounder (spotted halibut, slime flounder, marbled sole, sand flounder, stone flounder, frog fleunder and bastard halibut) were studied. The effect of heat treatment on quantitative change in the composition of amino acids and related compounds in the extract of sand fleunder muscle was also investigated since the sand flounder has much Ex-nitrogen in the extract of the muscle. The content of crude protein and that of pure protein were in the range of $17.54{\sim}19.99%$ and $15.63{\sim}17.95%$, respectively. Among the extracts of the seven fish muscle, stone flounder showed the highest content of Ex-nitrogen(2.12%). In the muscle extracts of the seven fish taurine was abundantly contained $(29.4{\sim}56.9%)$, and followed alanine $(6.6{\sim}10.4%)$ and glycine $(1.6{\sim}16.7%)$. The compositions of amino acids and related compounds were characterized by the existence of phosphoethanolamine, ${\alpha}-aminoadipic\;acid$, DL-allocystathionine, ethanolamine and ornithine. The experiments on amino acids and related compounds of the muscle extract of sand flounder with reference to heating time and temperature were resulted in that the amount of taurine, tyrosine, leucine and alanine were increased with the heating time at $100^{\circ}C$, whereas that of lysine, histidine, ${\alpha}-aminoadipic\;acid$ and proline were decreased with prolonged heating time. When heating temperature was changed from $90^{\circ}C$ to $130^{\circ}C$ for 60 min, the contents of taurine, alanine and leucine were increased, while that of histidine, lysine and aspartic acid were decreased.

• Development and Reproduction
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• v.13 no.4
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• pp.281-289
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• 2009

The slime flounder Microstomus achne were caught at Geomun Island, Yosu-si, Jeollanamdo from January to March in 2006. The fertilized eggs were observed for morphological development of egg, embryo and larva. Eggs were colorless transparent, separative pelagic, absent of oil globule, and the diameter was 1.64${\pm}$0.03 mm (n=50). The eggs were hatched at 168 hours 40 minutes after fertilization in the range of $9.8\sim13.0^{\circ}C$ (mean $11.4{\pm}1.6^{\circ}C$). Total length of newly hatched larva was 4.05${\pm}$0.18 mm (n=20). The larva had developed membranous fin showing waterdrop-shaped structure, and their mouth and anus were not open. The myotomes were 14~15+33~34=47~49. The egg yolks were 1.64${\pm}$0.12 mm in major axis, and 1.23${\pm}$0.19 mm in minor axis. At 12 days after hatching, the total length was 7.32${\pm}$0.42 mm(n=20). The egg yolk was completely absorbed and transferred to post larval stage. Star-shaped melanophores and branch-shaped xanthophores in the edge of membranous fin were more densed. Chrysanthemum-shaped melanophores in the notochord were densed and formed 4~5 melanophore bands. At 90~93 days after hatching, morphological features of the larva, 19.91${\pm}$1.63 mm TL(n=20), were transferred to juvenile stage showing similar features with those of the adult fish.