Ultrastructural aspects of the sperm and spermiogenesis in two species of paedomorphic gobioid fishes (Shindleria sp. and Leucopsarion petersii)

• Hara Masako

  Atmosphere and Ocean Research Institute, University of Tokyo

• Nakamura Shigeo

  琉球大学熱帯生物圏研究センター瀬底実験所

• Kitano Tadashi

  東海大学海洋学部

• Akiyama Nobuhiko

  東海大学海洋学部

Bibliographic Information

Other Title

• 幼形進化型ハゼ亜目魚類2 種（シラスウオ属の1 種とシロウオ）の精子変態過程

Abstract

Abstract Ultrastructural observations of spermiogenesis in two paedomorphic gobioid fishes, Schindleria sp. and Leucopsarion petersii, were discussed with special reference to the specialized morphology of their spermatozoa. In Schindleria sp., spermiogenesis was characterized by (1) apical vesicle generated from nuclear section and surrounded by cytoplasm, (2) flagellum implanted to centriole at base of nucleus, moving towards apical vesicle by piercing nucleus center to beyond nucleus tip, (3) apical vesicle spermatozoon subsequently disappearing, (4) nucleus of mature spermatozoon cylindrical, 3.2m m in length and ca. 0.5m m in width, (5)flagellum fully penetrating nucleus, resulting in sperm length equaling flagellum length and (6) single mitochondrion located at base of flagellum in contact with posterior end of nucleus. In Leucopsarion petersii, spermiogenesis was characterized by (1) a mass of small vesicles at nucleus tip forming apical point, (2) elongated apical point based on four rounded corners on top of ovoidal nucleus, (3) two centrioles located on basal body of nucleus, each with a typical flagellum, (4) both flagella with 92 axoneme pattern and (5) mitochondria varying in size and shape coalesce into a long midpiece. The spermatozoa of both species bear extremely specialized structures, such as the apical vesicle and the apical point, not yet reported in other teleosts. These structures are likely to have evolved within the less restricted framework of sperm morphology of gobioids, as reflected in the unusually high species diversity of this group.

Journal

• Japanese Journal of Ichthyology

  Japanese Journal of Ichthyology 57 (2), 93-103, 2010

  The Ichthyological Society of Japan

Keywords

• 幼形進化型ハゼ類
• シラスウオ属
• シロウオ
• 精子変態
• 微細構造

Details

• CRID: 1390001205512984576
• NII Article ID: 130003397795
• NII Book ID: AN00063212
• DOI: 10.11369/jji.57.93
• ISSN: 18847374
• ISSN: 00215090
• Text Lang: ja
• Data Source:
  • JaLC
  • CiNii Articles
• Abstract License Flag: Disallowed