The reproductive cycle in the population of Saccostrea cuccullatta (Born) from the coast of Karachi, Pakistan

Abstract

The annual gonadial changes of S . cuccullatta from the coast of Karachi (Lat . 24'50'N) show a different pattern of reproductive behaviour from that of the majority of oysters so far studied . Although loss of sexuality may be seen in the species, an `inactive' phase of the gonads is not noticeable in individuals from this coast . The stages of gametogenesis are staggered in different individuals of the population all the year round and in this sense continuous gonadial activity occurs in the species .

Temporal variation in the reproductive pattern of blood cockle Anadara antiquata from Pakistan (northern Arabian Sea)

“…In the present study, the salinity at Sonmiani was 40‰ to 46‰ and at Phitti Creek it was 38‰ to 45‰; the lowest water temperature at both sites was 21-22 °C in winter-spring (December to March), and it never exceeded 31 °C in summer-autumn (May to November). Gonadal maturation and spawning in A. antiquata seems to be associated with rising temperatures; this pattern of gonadal maturation with slight changes in temperature has been observed in many species of oysters, e.g., Crassostrea, Saccostrea, and Ostrea (Asif, 1980;Siddiqui and Ahmed, 2002a, 2002b, 2002c, 2003Siddiqui, 2005). Furthermore, according to Ahmed (1980), the extensiveness of the spawning season in marine animals of the Pakistani coast is also related to their tidal distribution.…”