• Title/Summary/Keyword: Atlantic halibut

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The Relationship between Monogenean Skin Parasite Entobdella hippoglossi and Mucous Cell Distribution of its Host the Atlantic Halibut Hippoglossus hippoglossus (Atlantic halibut, Hippoglossus hippoglossus에 기생하는 피부흡충, Entobdella hippoglossi의 기생밀도와 숙주 점액 세포와의 관계)

  • Yoon, Gil-Ha;Sommerville, Christina;Jo, Jae-Yoon
    • Korean Journal of Ichthyology
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    • v.11 no.2
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    • pp.134-138
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    • 1999
  • This study investigated the relationship between attachment site preference of the skin parasite, Entobdella hippoglossi and mucous cell density, moucus cell size and epidermis thickness on the surface of the Atlantic halibut Hippoglossus hippoglossus. Parasites occupying the ventral surface of their host were significantly longer and wider than those found on the other zones of the fish (P<0.05). The mean size of the mucous cells on the front region was significantly greater than the other regions on the dorsal and ventral surface (P<0.05). The average numbers of mucous cells and the epidermal thickness in the skin of the halibut were shown that the front region had significantly higher numbers of mucous cells and thicker layer than the rear region on the dorsal and ventral surface of the halibut, respectively (P<0.05).

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Host Finding Behavior of Oncomiracidium of Monogenean Parasite Entobdella hippoglossi from the Atlantic Halibut

  • Yoon Gil Ha
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.63-67
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    • 1998
  • The host finding behavior of Entobdella hippoglossi oncomiracidium, skin parasite of the Atlantic halibut was investigated. Almost of the parasite swam downward from the top to the bottom of the 150cm glass tube within 30 minutes. The average swimming speed of oncomiracidium was $0.32\pm0.10cm/second$ throughout the experiment. When the parasites arrived on the bottom of the glass tube, they moved upwards and downwards continuously within the 10cm of the bottom. This behavior would suggest that it may be one of the essential methods for host searching of the parasite. When the oncomiracidia was exposed different stimuli, they responded positively light and halibut mucus.

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Growth and nutrient uptake by Palmaria palmata integrated with Atlantic halibut in a land-based aquaculture system

  • Corey, Peter;Kim, Jang K.;Duston, Jim;Garbary, David J.
    • ALGAE
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    • v.29 no.1
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    • pp.35-45
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    • 2014
  • Palmaria palmata was integrated with Atlantic halibut Hippoglossus hippoglossus on a commercial farm for one year starting in November, with a temperature range of 0.4 to $19.1^{\circ}C$. The seaweed was grown in nine plastic mesh cages (each $1.25m^3$ volume) suspended in a concrete sump tank ($46m^3$) in each of three recirculating systems. Two tanks received effluent water from tanks stocked with halibut, and the third received ambient seawater serving as a control. Thalli were tumbled by continuous aeration, and held under a constant photoperiod of 16 : 8 (L : D). Palmaria stocking density was $2.95kg\;m^{-3}$ initially, increasing to $9.85kg\;m^{-3}$ after a year. Specific growth rate was highest from April to June (8.0 to $9.0^{\circ}C$), 1.1% $d^{-1}$ in the halibut effluent and 0.8% $d^{-1}$ in the control, but declined to zero or less than zero above $14^{\circ}C$. Total tissue nitrogen of Palmaria in effluent water was 4.2 to 4.4% DW from January to October, whereas tissue N in the control system declined to 3.0-3.6% DW from April to October. Tissue carbon was independent of seawater source at 39.9% DW. Estimated tank space required by Palmaria for 50% removal of the nitrogen excreted by 100 t of halibut during winter is about 29,000 to $38,000m^2$, ten times the area required for halibut culture. Fifty percent removal of carbon from the same system requires 7,200 to $9,800m^2$ cultivation area. Integration of P. palmata with Atlantic halibut is feasible below $10^{\circ}C$, but is impractical during summer months due to disintegration of thalli associated with reproductive maturation.

Scanning Electronic Microscopy Examination for the Egg of Skin Parasite, Entobdella hippoglossi on the Commercially Important Culture Fish, the Atlantic Halibut, Hippoglossus hippoglossi

  • Yoon Gil Ha
    • Fisheries and Aquatic Sciences
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    • v.1 no.1
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    • pp.68-71
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    • 1998
  • The egg structure and shape of the skin parasite, Entobdella hippoglossi from the Atlantic halibut, Hippoglossus hippoglossus was examined using scanning electronic microscope. The newly produced eggs of E. hippoglossi were yellowish in color and tetrahedral in shape. The eggs were entwined together in a complicated chain-like fashion by a long filament. The appendage showed the presence of buoy-like structures. The buoy-like structures on the appendage of the eggs of E. hippoglossi in the present study were totally different from other sticky droplets. It is suggested that these structures are not sticky droplets but buoys for floating eggs which have entwined together on the bottom of the sea. It seems that these buoy-like structures may be needed for preventing the eggs from being covered by mud or particles and thus maintaining the eggs in an oxygenated environment.

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Oncomiracidium of monogenean skin parasite Entobdella hippoglossi on the Atlantic halibut Hippglossus hippoglossus

  • Yoon, Gilha;Shinn, Andrew;Sommerville, Christina;Jo, Jae-Yoon
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.05a
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    • pp.433-433
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    • 2000
  • The monogenean skin parasite, Entobdella hippoglossi has commonly be found broodstock of the Atantic halibut. Heavy infestation of the parasite appears to be serious problem to the halibut farming industry. However, because the behavior of host, research on this parasite is not yet be carried out. The present study, therefore, was investigated the oncomiracidium of Entobdella hippoglossi to the basic step for solving this problem. (omitted)

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Induced Expression of Doublesex-and mab-3-related Transcription Factor-1 (DMRT-1) mRNA by Testosterone in the Olive Flounder, Paralichthys olivaceus ovary (Testosterone 처리에 의한 넙치, Paralichthys olivaceus 난소에서 doublesex-and mab-3-related transcription factor-1 (DMRT-1) mRNA의 발현 유도)

  • Jo, Pil-Gue;An, Kwang-Wook;Kim, Na-Na;Choi, Yong-Ki;Cho, Sung-Hwoan;Min, Byung-Hwa;Lim, Han-Kyu;Choi, Cheol-Young
    • Journal of Aquaculture
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    • v.20 no.3
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    • pp.199-202
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    • 2007
  • We isolated a 317 bp of partial cDNA for doublesex-and mab-3-related transcription factor-1 (DMRT-1) from the testis of olive flounder, Paralichthys olivaceus using RT-PCR. Based on the multiple sequence alignment, olive flounder DMRT-1 shared relatively high sequence homology (82 to 94%) with orthologues from other teleost species such as Atlantic halibut, Hippoglossus hippoglossus, black porgy, Acanthopagrus schlegeli and rainbow trout, Oncorhynchus mykiss. DMRT-1 mRNA was predominantly expressed in the testis of olive flounder. In our investigation for the effect of testosterone treatment in vivo on induced expression of ovarian DMRT-1 transcript, mRNA levels of DMRT-1 in ovary were significantly up-regulated by testosterone treatments (0.3 or $3.0{\mu}g$ testosterone/g body weight for 12 to 36 hours) as judged by RT-PCR analysis. In overall, transcriptional stimulation of DMRT-1 during treatments was more affected by doses of testosterone than treatment durations. This result strongly suggests that the regulation of DMRT-1 be tissue- and gender-specific in olive flounder, and also provides useful baseline knowledge on the testosterone-mediated regulation in the reproductive physiology of this species.