Borcherding, Jost, 1995. Laboratory Experiments on the Influence of Food Availability, Temperature and Photoperiod on Gonad Development in the Freshwater Mussel Dreissena polymorpha. University of Cologne

Reprinted from Malacologia (1995) 36(1-2): 15-27

Laboratory Experiments on the Influence of Food Availability, Temperature and Photoperiod on Gonad Development in the Freshwater Mussel Dreissena polymorpha

Abstract
(1) Two groups of the mussel Dreissena polymorpha were collected in March (El) and September (E2). Each group consisted of individuals at different stages of the annual gonadal cycle (e.g. females: in El had high numbers of oocytes still increasing in size, females in E2 had empty but recrudescent gonads). (2) Each group was kept for three months under nine different combinations of temperature (5, 12º, 19ºC) food availability (high and low), and photoperiod (LD 16:8 and 8:16). At each temperature (except at 5ºC with El), a high availability of food resulted in significantly larger gonads. (3) When food availability was high, the maximum gonad volume always occurred at 12ºC. A low availability of food caused a progressive decrease in gonad volume at increasing temperatures. An influence of the photoperiod (tested at low food availability at all three temperatures) was not established. (4) The increase in oocyte size to maturity in the El-series correlated positively with increasing temperatures. Simultaneously, the number of oocytes decreased significantly, and it appears that oocytes were reabsorbed in order to support maturation of the remaining oocytes. (5) An ample supply of food influenced oocyte development positively. No influence of photoperiod was observed. (6) The results are discussed with respect to the spread of D. polymorpha.

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Contact: Jost Borcherding, Zoological Institute, University of Cologne, Physiological Ecology, Weyertal 119, D-50923 Koln, Germany
Keywords: Zebra_mussel, Basic_biology
Product Type: Research, Basic_biology
User Type: Resource_management