ISSN:
1432-0878
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Spermatozoa of two primitive crustaceans have been examined with phase contrast and electron optics. The organisms are Hutchinsoniella macracantha of the subclass Cephalocarida and Derocheilocaris typicus of the subclass Mystacocarida. The H. macracantha sperm consists of a compound acrosome, a nucleus and a rod-like structure that extends from the base of the acrosome, through a nuclear canal to project posteriorly. Although this posterior projection seems to contain fibrils, it clearly lacks the characteristic “9 doublets + 2” microtubular structure of sperm flagella. No mitochondria or centrioles were found and sperm motility was not observed. The D. typicus sperm consists of a trough-shaped acrosome, a nucleus, mitochondria and a flagellum. The flagellum and two lateral rows of mitochondria, as well as the nucleus, arise at the base of the acrosome. These relationships impart a bilateral symmetry to the sperm. Mature D. typicus spermatozoa are stored in spermatophores in the vas deferens. These spermatophores are tubes each containing two spermatozoa. The spermatozoa in these tubes are oriented with a high order of precision. The ends of the spermatophores are closed by plugs with complex ultrastructure. No indication has been found as to the site or mechanism of enclosing the spermatozoa in the spermatophores. The sperm morphology is discussed in terms of crustacean phylogeny.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00331478
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