New Damietta shore is one of the important areas for collection of the clams as well as mullet, seabass
and seabream larvae which are reliable for marine aquaculture in Egypt. The reproductive cycle of the
clam; Donax variabilis (Say, 1822), in this shore was investigated during the period from May 2008 to
July 2009. Reproductive maturity was estimated by assessment of gonad index and microscopic
examination of gonadal smears and sections. The different stages of the reproductive cycle were
characterized by histological examination. Six distinguishable gonad stages were determined in both
male and female clams viz., early active, late active, ripe, partially spawning, completely spawning and
spent stage. Both males and females showed synchronism in gonadal development. Spawning occurred
between May and August with one major spawning phase. Donax variabilis is a dioecious species
without sexual dimorphism or sex reversals. The ratio of males to females (1 M: 0.85 F) was statistically
non-different from the theoretical sex ratio of 1:1 (X2 = 8.70, P > 0.05).
New Damietta shore is one of the important areas for collection of the clams as well as mullet, seabassand seabream larvae which are reliable for marine aquaculture in Egypt. The reproductive cycle of theclam; Donax variabilis (Say, 1822), in this shore was investigated during the period from May 2008 toJuly 2009. Reproductive maturity was estimated by assessment of gonad index and microscopicexamination of gonadal smears and sections. The different stages of the reproductive cycle werecharacterized by histological examination. Six distinguishable gonad stages were determined in bothmale and female clams viz., early active, late active, ripe, partially spawning, completely spawning andspent stage. Both males and females showed synchronism in gonadal development. Spawning occurredbetween May and August with one major spawning phase. Donax variabilis is a dioecious specieswithout sexual dimorphism or sex reversals. The ratio of males to females (1 M: 0.85 F) was statisticallynon-different from the theoretical sex ratio of 1:1 (X2 = 8.70, P > 0.05).