Sperm Sphere in Unionid Mussels (Bivalvia: Uniondae).

Autor: Ishibachi, Ryo, Komaru, Akira, Kondo, Takaki
Předmět:
Zdroj: Zoological Science (VSP International Science Publishers); Sep2000, Vol. 17 Issue 7, p947, 4p
Abstrakt: We observed spermatozoa of five freshwater Japanese unionid mussel species under a light microscope. Males discharged spermatozoa as spherical masses. Spermatozoa embedded their heads into a spherical, colorless body with their tails extended around the sphere. We termed this spherical mass of sperm as a "sperm sphere". Just after release the sperm spheres rotated rapidly by synchronous movement of the sperm tails. By the next day, the sperm spheres increased in size and some spermatozoa had detached from the sperm spheres. Spermatozoa embedded in the sperm sphere were active at least forty-eight hours after being discharged. Single spermatozea in a balanced salt solution were also active until forty-eight hr after extraction from the gonads, while they Iost their motility within a few minutes in freshwater. Spermatozoa may maintain their motility for a Iong time in the form of a sperm sphere and the use of sperm spheres may allow the fertilization of eggs discharged into the gill chambers of females far away from the male. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index