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Abstract:
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From the point of view of rational exploitation and proper management
of the fishery resources as well as for the development of intensive aquaculture
of fishes through selective breeding, brood stock development, domestication
and genetic improvement, a sound knowledge of reproductive biology and
physiology of the candidate species is of great importance. In recent times, a
wealth of information on maturity, spawning habits, spawning periodicity, spawning
season, size at maturity and fecundity of commercially important fishes
has been generated.
Gametogenesis involves the transformation of Primordial germ cells in
the gonads into specialised cells or gametes, namely ova in the female and
sperms in male, through a series of complex morphological and cytological
events. The formation of male gamete is known as spermatogenesis. In the
female, the primary growth phase involving the formation of primary oocyte
from oogonia is known as oogenesis, which would be followed by the secondary
growth phase, in which considerable increase in the size of the oocyte occurs,
due mainly to accumulation of yolk. This process is known as vitellogenesis,
which would be followed by final maturation and ovulation of the ova.
In the present work, basic aspects of maturation and spawning, salient
features of gametogenesis and associated biochemical changes occurring during
these processes in an important cultivable fish, Sillago sihama belonging to
the family Sillaginidae have been investigated. |