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USGS · 1000758

Preference of redear sunfish on zebra mussels and rams-horn snails

John R. P. French·Michael N. Morgan
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Abstract

We tested prey preferences of adult (200- to 222-mm long) redear sunfish ( Lepomis microlophus ) on two size classes of zebra mussels ( Dreissena polymorpha ) and two-ridge rams-horns ( Helisoma anceps ) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

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John R. P. French, Michael N. Morgan. 2011-01-06. Preference of redear sunfish on zebra mussels and rams-horn snails. https://doi.org/10.1080/02705060.1995.9663416

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