BIOTIC Species Information for Corbula gibba
|Researched by||Lizzie Tyler||Data supplied by||University of Sheffield|
|Refereed by||This information is not refereed.|
|Reproductive Season||Summer - Autumn||Reproductive Location||Insufficient information|
|Reproductive frequency||Annual protracted||Regeneration potential||No|
|Life span||1-2 years||Age at reproductive maturity|
|Generation time||See additional information||Fecundity|
|Egg/propagule size||Fertilization type||Insufficient information|
|Reproduction Preferences Additional Information||Reproduction
Yonge (1946) determined that Corbula gibba was dioecious with no evidence of a sex change. When the gonads of Corbula gibba are maturing it is easy to distinguish between males and females. Males have white testes whereas females have pink ovaries (Yonge, 1946).
Reproduction and spawning generally occur during summer and autumn. Yonge (1946), observed that during early August the male gonads were filling but were not yet ripe and that the testes had developed further than the ovaries. There were however, no active sperm present. In late August, it was noted that in female Corbula gibba the ovaries were filling. No ripe sperm was found until the middle of September. By the end of September the male and female specimens were ripe. The ripe females had relatively large yolky eggs and ripe males had very active sperm (Yonge, 1946).
Fosshagen, (1965; cited in Muss, 1973) found larvae of Corbula gibba in plankton from October - November and once again from January - February and suggested that it was possible for large individuals to spawn during the autumn.
Larval Settling Time
The settling time of Corbula gibba larvae is variable depending on location and may take several months (Jensen, 1988). In Danish waters settlement occurred in August. (Jensen, 1988) states that the settlement of Corbula gibba is very distinct with very few specimens below 2 mm in size during the month of September in Limjford. The recruitment of Corbula gibba was achieved within one week after settlement (Jensen, 1988). However, high moralities of newly settled individuals occurred during the first month of settling. It was suggested that this was may be due to predation from epibenthic predators. Low and constant mortality occurred during the winter months with decreases in abundance again in spring and early summer. It was suggested that these observation could be due to the weakened conditions in the bivalves that had spawned (Jensen, 1988).
Jensen (1990) suggested that the life span of Corbula gibba seems to be shorter at 1 -2 years in Nissum Bredning than in the first part of this century when individuals had a life span of 5 -6 years with a maximum size of 12 mm (Jensen 1919: cited in Jensen, 1990).
|Reproduction References||Jensen, 1990, Jensen, 1988, Yonge, 1946, Muus, 1973, Eckert, 2003,|