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Two sperm types in the spermatozeugmata of Tubifex tubifex (annelida, oligochaeta)
Author(s) -
Braidotti Paola,
Ferraguti Marco
Publication year - 1982
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051710202
Subject(s) - biology , spermatheca , sperm , flagellum , tubifex tubifex , acrosome , oligochaeta (plant) , anatomy , glycogen , microbiology and biotechnology , botany , zoology , ecology , biochemistry , gene
The spermatozeugmata (sperm bundles lacking a distinct wall) from the spermathecae of Tubifex tubifex are composed of two different zones: an internal axial cylinder containing conventional spermatozoa and an external cortex composed of modified spermatozoa, tightly packed together. The conventional spermatozoa conform to the classical clitellate scheme: very long and thin with a complex acrosome, a filiform nucleus, small mitochondria, and a flagellum with Y links and β glycogen granules as accessory structures. The modified spermatozoa show “empty” acrosomes, degenerating nuclei, and tails which contain γ glycogen granules. The tails are helically wound around the spermatozeugma and are connected to each other by junctional complexes. The tips of the cortical tails are free and move with a metachronal wave. The presence of two sperm types in tubificids is discussed and a protective function for the modified cortical spermatozoa is proposed.