ツマグロカジカ, <I>Gymnocanthus herzensteini</I> Jordan and Starks の胚発生および仔魚 Embryonic Development and Larvae of <I>Gymnocanthus herzensteini</I> Jordan and Starks

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Abstract

1968年1.月20日, 北海道噴火湾口鹿部村沿岸で漁獲された本種成熟魚を用い, 湿導法により人工受精を行ない, 卵および孵化仔魚を水温5.5°~6.8℃の静水海水中で飼育した.卵は球形沈性粘着卵で, 卵径は1.64~1.73mm, 大型油球1個をもち, 油球側に頼粒物質群がある.卵黄は淡橙色である.胚発生は一般の硬骨魚卵のそれと大差ない.受精後42日目から孵化を開始した.孵化直後の仔魚は体長5.57~6.12mm, 筋節数41~43で, 活発に遊泳する.孵化後約15日で卵黄を吸収し, 39日で体長7.22~8.51mmに達した.黒色素胞は頭頂部, 頭後方背部, 腹腔部, 尾部下側部に, また, 黄色素胞は頭頂部, 腹腔部にそれぞれ観察された。仔魚期の体形の変化をアロメトリー式で検した.体長に対して優比成長を示す体部分は肛門前体長, 頭長および耳胞径であり, 等比成長の部分は眼径, 劣比成長の部分は尾長である.胴長は卵黄吸収時に変移点をもち, 劣比成長から等比成長に変わる.

The eggs of <I>Gymnocanthus herzensteini</I> were fertilized and cultured for the study of their embryonic and larval development.The eggs were demersal and adhesive.The yolk was light orange in color with a single large oil globule, sometimes accompanying a few small oil globules, and contained a mass of many small granular materials.Melanophores and xanthophores appeared on the embryonal body after the mid-stage of embryonic development, but not on the yolk and oil globule.Hatching occurred between 42 and 49 days after fertilization at the water temperature 5.5°-6.8°C.<BR>The newly hatched larvae averaged 5.83 mm in body length with 41-43 pairs of somites.The prominent characteristic of larvae lay in the pigmentation pattern of melanophores and xanthophores on the nape, the crown of the head, the body cavity, and especially on the ventral margin of the tail portion.After thirty-nine days, the larvae reached an average body length of 7.84 mm.The pigmentation pattern remained essentially unchanged except the appearance of melanophores on the lower jaw and the opercle region.Various body parts were measured to examine the changes in body form in the larval stage.

Journal

  • Japanese Journal of Ichthyology

    Japanese Journal of Ichthyology 17(2), 74-79, 1970

    The Ichthyological Society of Japan

Codes

  • NII Article ID (NAID)
    130003825878
  • Text Lang
    UNK
  • ISSN
    0021-5090
  • Data Source
    J-STAGE 
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