• Journal of Aquaculture
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• v.22 no.1
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• pp.5-10
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• 2009

Spermatogenesis in male yellow croaker Larimichthys polyactis was histologically investigated by sampling testicular tissue from $2{\sim}3$ years old wild fishes captured from the coast of Mok-Po, South Korea. Spermatogenesis was characterized histologically, and staged according to the most advanced type of germ cell present. Annual reproductive cycle was classified into the following successive 4 stages: spermatogonia from August to September (rest stage), spermatogonia and spermatocytes from October to December (growth stage), spermatogonia, spermatocytes and spermatids from January to February (maturation stage), spermatogonia, spermatocytes, spermatids and spermatozoa from March to May (spermiation stage IV), and regressing testis from June to July (degeneration stage).

• Journal of Life Science
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• v.31 no.3
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• pp.314-320
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• 2021

In the present study, we investigated the effect of photoperiod and water temperature on the gonadosomatic index (GSI), histological stage of the testes, and plasma levels of sex steroid (testosterone, T; 11-ketotestosterone, 11-KT) hormones in cultured male small yellow croakers (Larimichthys polyactis). In a photoperiod experiment, small yellow croakers were reared under a natural photoperiod (NP, 10L:14D-11L:13D), long photoperiod (LP, 14L:10D), and short photoperiod (SP, 10L:14D) at 17℃ for 90 days. The GSI was significantly higher in the LP group than in the other groups at 30 and 60 days. The plasma 11-KT levels were significantly higher in the LP group than in the other groups at 30 days. In a water temperature experiment, small yellow croakers were reared under natural water temperature (NT, 19.1-15.0℃), or at 17℃, 21℃, or 25℃ under a LP (14L:10D) for 60 days. The GSI was significantly lower for the 25℃ group than for the other groups at 30 and 60 days. The plasma 11-KT levels were significantly lower for the 25℃ group than for the other groups at 60 days. Therefore, the sexual maturation of cultured male yellow croakers was promoted by LP and inhibited at water temperatures above 25℃. These findings suggest that the sexual maturation of cultured male small yellow croakers is controlled by both the photoperiod and the water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.315-323
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• 2023

The maturity and spawning of the large yellow croaker Larmichthys crocea were investigated using samples randomly collected in the Jeju coastal area, Korea. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), and egg diameter. Additionally, we verified fecundity by size class and total length (TL) at sexual group maturity at 50%, 75%, and 97.5%, as well as by sex ratio (female vs. male). The overall sex ratio of females to males was 1:0.42. The GSI values showed a peak in October, but the spawning season, revealed by the microscopic analysis of gonadal tissue of L. crocea was from October 2021 to March 2022, with the main spawning period from October to November. The fecundity (F) of female L. crocea ranged from 39,232 eggs at 20 to 29.9 cm to 251,003 eggs at 50 to 59.9 cm, with the relationship between TL and F being 80.244TL-1641.6. In females, TL at 50%, 75%, and 97.5% maturity was 22.4, 24.3, and 29.0 cm, respectively.

• Journal of Sasang Constitutional Medicine
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• v.13 no.3
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• pp.59-74
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• 2001

In oriental medicine, food are regarded as important one like medicine. Especially Sasang medicine put emphasis on diet, it regarded food as a important one by taking food according to their own constitution in the point of improving health condition and preventing diseases. In this report, the author try to find out the relationship between food preference and each suitable food according to Sasang constitution by using survey data. The results are like this. 1. In constitutional distribution patterns among 203 person(male : 118 person, female : 85 person) reveal Soyang Group 58person(28.6%), Taeum Group 61(30%) and Soeum Group 84(41.4%). And their were no significant difference in their height in all group according to gender. Compared with the other groups, When compared with the other groups on body weight and BMI, Taeum Group indicate significantly high body weight and BMI(Body Mass Index) in both gender. 2. Taeum Group show significantly high smoking rate. But alcohol drinking rates reveal no significant difference in all groups. 3. In the Survey about food preference according to the constitution, rice, Soju, watermelon show significantly high preference in case of suitable food to each group. But perilla seeds, coffee, ginger tea show insignificant results. 4. In the survey about food preference according to the constitution and sex, welsh onion, crab preserved with soysauce, beer show significantly high preference in case of suitable food to each group. But glutinous rice, cooked barley, water dropwort muchim, lettuce, dog meat, egg, yellow croaker, coffee, ginger tea, and Soju show insignificant results. 5. In the survey about food preference according to the constitution and age, rice, watermelon, onion, garlic, salt and Soju show significantly high preference in case of suitable food to each group. But sugar and perilla seeds show insignificant results. 6. In the survey about food preference according to constitution, sex and age, glutinous rice, soybean milk, banana, crab preserved with soysauce, sea cucumber, sea mustard, Soju, beer, onion, garlic, salt show high preference in case of suitable food to each group. But cooked barley, sugar, water dropwort muchim, dog meat, puffer soup and perilla seeds show insignificant results.