Zoomorphology

, Volume 118, Issue 3, pp 159–168

Four lines of spermatid development and dimorphic spermatozoa in the sea urchin Anthocidaris crassispina (Echinodermata, Echinoida)

  • D. W.-t. Au
  • Arkadiy Anatolievich Reunov
  • Rudolf Shiu-sun Wu
ORIGINAL ARTICLE

DOI: 10.1007/s004350050065

Cite this article as:
W.-t. Au, D., Reunov, A. & Shiu-sun Wu, R. Zoomorphology (1998) 118: 159. doi:10.1007/s004350050065

Abstract

 The process of sperm development in the sea urchin Anthocidaris crassispina was studied by light and electron microscopy. Similar to other echinoids studied, a single flagellum, striated rootlet and nuage-like materials were present in spermatogonia of A. crassispina. Spermatocytes near the diplotene stage showed intracellular localization of the axoneme which appeared to be a retracted flagellum prior to cell division. Fibrous filaments were associated with a proximal centriole in spermatocytes and spermatids and might be involved in movement of the proximal centriole. An acrosomal vesicle was developed and a residual body was formed in spermatids. The special development patterns in A. crassispina attributed to the presence of two patterns of tail development and two patterns of mitochondrial development during spermiogenesis. These four lines of spermiogenesis resulted in the formation of four morphological types of sperm cell, i.e. sperms with: (1) a symmetrical midpiece and posterior tail, (2) an asymmetrical midpiece and posterior tail, (3) a symmetrical midpiece and bent tail and (4) an asymmetrical midpiece and bent tail. Sperm cells with bent tails (type 3+4) were probably still at the late spermatid stage because results of scanning electron microscopy demonstrated gradual detachment and eventual straightening of the bent tail, and their percentage occurrence in the sperm population decreased significantly (P<0.05) towards the spawning season of A. crassispina. Spermatozoa with a symmetrical midpiece were dominant (averaging 70% occurrence in the sperm population) over those with an asymmetrical midpiece. The dimorphic spermatozoa in A. crassispina (types 1, 2) are both considered to be euspermatozoa as their morphology is typical for Echinoida.

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • D. W.-t. Au
    • 1
  • Arkadiy Anatolievich Reunov
    • 2
  • Rudolf Shiu-sun Wu
    • 1
  1. 1.Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong e-mail: bhdwtau@cityu.edu.hk, Fax: (852) 2788 7406HK
  2. 2.Institute of Marine Biology, Far East Branch of Russian Academy of Sciences, 17 Paltchevsky Street, 690041 Vladivostok, RussiaRU

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