Wt. Claxton et Gl. Mackie, Seasonal and depth variations in gametogenesis and spawning of Dreissena polymorpha and Dreissena bugensis in eastern Lake Erie, CAN J ZOOL, 76(11), 1998, pp. 2010-2019
Citations number
36
Categorie Soggetti
Animal Sciences
Journal title
CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE
Dreissena polymorpha and Dreissena bugensis are two exotic species of dreis
senid mussels introduced into the Great Lakes within the past decade. Dreis
sena bugensis profunda is a morphologically distinct dreissenid taxon, repr
esenting either a third species or a phenotype of D. bugensis. In in situ m
ussels, D. polymorpha and D. bugensis from the wave zone spawned simultaneo
usly, approximately 1 week before D. bugensis profunda from the epilimnion
and hypolimnion. Dreissena bugensis profunda from the hypolimnion spawned a
t 9 degrees C, which is below the previously accepted minimum dreissenid sp
awning temperature (12 degrees C), and may explain why D. bugensis profunda
is proliferating in the hypolimnion. The gametogenic index of all taxa was
significantly correlated with temperature at all sites. The gametogenic in
dex of D. bugensis profunda from the epilimnion and hypolimnion was signifi
cantly correlated with water protein and chlorophyll a content, respectivel
y. In mussels transplanted to the epilimnion, D. bugensis and D, bugensis p
rofunda spawned simultaneously between August 18 and 28, approximately 2 we
eks before D. polymorpha. In mussels transplanted to the hypolimnion, D. bu
gensis and D. bugensis profunda spawned between July 27 and August 18 at a
temperature of 9-10 degrees C. Dreissena polymorpha neither spawned nor sho
wed significant gametogenic development, which suggests that this taxon can
not successfully colonize hypolimnial waters.