• Ocean and Polar Research
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• v.30 no.4
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• pp.401-406
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• 2008

Early gonadal development and sexual differentiation of dark-banded rockfish (Sebastes inermis Cuvier) were followed from parturition to 400 days post parturition (dpp). During this period, average total length (TL) increased from 0.57 to 13.18 cm. Primordial germ cells (PGCs) were first detected at 0.68 cm TL (10 dpp). When fish reached 1.52 cm TL (50 dpp), initial stages of ovarian differentiation were identified by the presence of PGCs containing condensed chromatin and their transformation into meiotic oocytes. At 10.23 cm TL (300 dpp), the ovaries gradually developed into oocytes in the primary yolk stages. Ovary growth was rapid after sex differentiation, but testis tissue continued to multiply without growing until fish reached 6.97 cm TL (200 dpp), after which the production of spermatocytes, spermatogonia, and cyst cells was apparent. Histological analysis of gonadal structure suggested a gonochoristic sexual development pathway. Our analysis of the sex ratio at 400 dpp showed a significantly higher proportion of males.

• Journal of Aquaculture
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• v.18 no.3
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• pp.147-153
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• 2005

The objective of this study is to elucidate the growth pattern of dark-banded rockfish, Sebastes inermis Cuvier, produced by aquaculture in Korea. Larvae from 250 maternal full-sibs were reared until 1,350 days after parturition. During the rearing period, growth equations on days after parturition (X) to the total length (TL) and body weight (BW) were estimated as TL=0.0217X $(r^2=0.8867)$ and $BW=0.0001X^2+0.0713X\;(r^2=0.9858)$, respectively. The relationship between BW and TL was $BW=0.0072TL^{3.4373}\;(r^2=0.9945)$. An increases in the eye diameter (ED) of dark-banded rockfish larvae on days after parturition (X) could be expressed as $ED=-2E-5X^2+0.0326X\;(r^2=0.9886)$. Relative growth equations on TL to head length (HL), snout length (SL), ED and postorbital head length (PHL) were calculated as $HL=0.2652TL\;(r^2=0.9758),\;SL=0.0613TL\;(r^2=0.9602),\;ED=0.0752TL\;(r^2=0.9715)$ and $PHL=0.2652TL\;(r^2=0.9501)$, respectively. Since there were few reports on the long-term growth experiment of this species due to difficulties in rearing techniques, results of this study would give a useful information to the biology and commercial culture techniques of dark-banded rockfish.

• Journal of Species Research
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• v.1 no.2
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• pp.175-217
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• 2012

Thirteen species of sea lice (Copepoda, Caligidae) are described as parasites of marine fishes from Korea including three new species such as Pseudocaligus longipes n. sp. from Siganus fuscesens (Houttuyn), Lepeophtheirus tamladus n. sp. from Sebastes inermis Cuvier, and Lepeophtheirus gusevi n. sp. from Sebasetes schlegeli Hilgendorf. Remaining ten species are new to Korea: Caligus elongatus Nordmann, 1832; C. equulae Ho and Lin, 2003; C. fistulariae Yamaguti, 1936; C. laticaudus Shiino, 1960; C. rotundigenitalis Y$\ddot{u}$, 1933; Metacaligus uruguayensis (Thomsen, 1949); Lepeophtheirus atypicus Lin, Ho and Chen, 1996; L. parvulus Shiino, 1952; Anuretes quadrilaterus Shiino, 1954; and Pseudanuretes chaetodontis Yamaguti, 1936.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.330-334
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• 1983

The author carried out an experiment to find out the response of gray rock cod, Sebastes inermis (Cuvier et Valenciennes) to the color light. The experimental tank ($360L{\times}50W{\times}55H\;cm$) was set up in a dark room. Six longitudinal sections with 60 cm intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 cm level. Light bulbs of 20W at the both ends of the tank projected the light horizontally into the tank. Two different colored filters were selected from four colors of red, blue, yellow, and white, and they were placed in front of the light bulbs to make different colors of light. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fishes were acclimatized in the dark for 50 minutes before they were employed in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in 30 second intervals, and the mean of the number of fish in each section was given as the gathering rate of the fish. The colors favourited by the fish was found in the order of white, blue, yellow and red. The gathering rate of fish on illumination period was small and comparatively fluctuated with stability. The difference of the gathering rates on two different colors of light was much greater, regardless of illumination period, in day time than in night time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.59-65
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• 1981

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by rising two species of commercial fishes: gray rock cod. Sebastes inermis (Cuvier et Valenciennes) and cat shark, Scyliorhinus torazame (Tanaka). An experimental tank $(360L\;{\times}\;50W\;{\times}\;55H\;cm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. The light intensity inducing maximum gathering rate is as follows: gray rock cod: 16.6 lux (10.6-24.5 lux) (day), 0.7 lux (0.5-1.1 lux) (night), cat shark: 1.9 lux (1.2-2.9 lux) (day), 16.6 lux(10.6-24.5lux) (night). Trend of the gathering rate in illumination time revealed different results in two fish species. Gathering rate of gray rock cod did not show any definite pattern but fluctuated irregularly. The gathering rate was some fluctuating at night. However, that of cat shark was almost constant and did not show any distinctive difference between day and night.