ISSN:
1432-0878
Keywords:
Spermatozoa
;
Eudendrium
;
Hydroidea
;
Coelenterata
;
Ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Spermatozoa of the colonial marine hydroid, Eudendrium were examined with the electron microscope. The spermatozoa of this species were found to differ greatly in structure from previously described spermatozoa in the phylum. The mature sperm are acrosomeless and retain a considerable amount of perinuclear cytoplasm following their maturation. The perinuclear cytoplasm contains numerous organelles: Golgi apparatus, endoplasmic reticulum, multivesicular bodies, ribosomes and membranous vesicles. The nucleus is elongate and cylindrical, rather than conical, in shape. The four wedge-shaped mitochondria which lie posterior to the nucleus form a fossa which contains proximal and distal centrioles. Centriolar satellites are associated with the distal centriole. The relatively short (15 μ) flagellum consists of two distinct segments: a proximal thick portion and a distal thin portion. The thick segment contains the typical 9+2 arrangement of tubules plus a variable number of peripheral, supernumerary tubules. The thin segment contains from one to eleven tubules. The morphological differences between the spermatozoa of Eudendrium and those of closely related species are discussed with particular reference to sexual life history.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00307008
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