
TY  - JOUR
A1  - Styan, C. A. 
A1  - Butler, A. J. 
T1  - Asynchronous patterns of reproduction for the sympatric scallops <emph type="2">Chlamys bifrons</emph> and <emph type="2">Chlamys asperrima</emph> (Bivalvia: Pectinidae) in South Australia
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 2003
VL  - 54
IS  - 1
SP  - 77
EP  - 86
KW  - bivalve, gamete release, reproductive cycle, spawning, synchrony.
UR  - https://doi.org/10.1071/MF02019 
N2  - Patterns of spawning activity were assessed by monitoring gonad states over 2.5 years for Chlamys asperrima and Chlamys bifrons at two sites in Gulf St Vincent, South Australia. Chlamys asperrima appeared to have a minor spawning in June, followed by a major spawning starting in late August. In contrast, the gonads of C. bifrons were regressed only during winter and it appeared that C. bifrons spawned for a long period, from late spring (September) until early autumn (March). At one site where sampling was frequent, there was evidence of three series of C. bifrons spawning events during the summer of 1994/95 and at least two series of events during 1995/96. Build-up and decrease in gonad weight was quick, but there was strong evidence of serial spawning for both species. Subsequently, we once observed C. asperrima spawning in situ at Edithburgh Jetty, at a time when gonad weights had been decreasing in previous years, but also long after the time when peak gonad weights had usually occurred. Only patches within the population were seen spawning, with scallops not spawning observed less than 100 m away from those that were. Indirect sampling of gonad condition also suggested that spawning in C. bifrons at Largs Bay was not always synchronous among patches of scallops within a population, nor always between sexes within patches. 
ER  -

