Abstract
D.Sc. (Zoology)
The spermatogenesis of two freshwater species from South Africa, Barbus
marequensis and B. polylepis, and three fresh water species from Israel, B. canis,
B. longiceps and Capoeta damascina, was studied.
A histological comparison of the process of spermatogenesis was undertaken. The
breeding cycle of B. marequensis, B. polylepis, B. canis, B. longiceps and C.
damascina was similar to the breeding cycle of B. aeneus and four phases occured
within the cycle. The four distinctive phases are post spawning phase, rest phase, pre-spawning phase and the spawning phase (Vlok, 1986) .
During the post spawning phase a decline in sperm development is observed and
possible lisosomal activity is responsible for the resorption of sperm cells not shed
during the spawning phase. The presence of collagen structure provides a
distinctive character to the tissue of the testis.
The resting phase is characterised by the absence of the lobular structure and the
testis is dominated by the collagen tissue. The testis is small and unobtrusive in
the abdominal cavities of both species.
At the onset of the pre-spawning phase, the testis is filled with spermatogonia.
The lobular structure becomes more prominent and the interstitial tissue can be
distinguished. Later during the phase, the synchronised development of sperm
cells in the cysts of the lobules can be observed, whilst sperm cells in adjacent
lobules are in different stages of development.
During the spawning phase the testis of all species studied contain mature sperm .
cells in the lumens of the lobules.