Reproductive activity of an androdioecious population of clams of the genus Corbicula

Gonadal Cycle of Corbicula largillierti (Bivalvia: Cyrenidae) in a Pampean Streams, Argentina

“…The populations of Corbicula species show a varied sex composition according to their distribution, from dioecious populations found in the native region, to hermaphrodites, with males or females in a low proportion, and which are characteristic of the invaded areas, although they are also found in native regions [24,26,34]. According to Pigneur et al [27], free spawning for external fertilization in freshwater dioecious bivalves is considered a primitive condition (e.g., Corbicula sandai Reinhardt, 1878 and Corbicula japonica Prime, 1864).…”

“…indicate that the number of reproductive events (spawning and fertilization) throughout the year is variable [14,23]. Several authors describe two annual reproductive events [21,26], while others report only one or three [25,42]. Two reproductive peaks were mentioned for C. fluminea in California and Arkansas, while in Kentucky, a region with a cooler climate, only one peak per year was noted [43].…”

“…populations differs among regions. Dioecy, simultaneous hermaphroditism, gynodioecy, and trioecy were reported in the native range, while hermaphrodites with occasional male and/or female specimens were reported in the invaded area [23][24][25][26]. Furthermore, androgenetic hermaphroditic asexual reproduction has been described for the invaded areas [27].…”