Feeding behavior of newly
settled winter flounder (Pseudopleuronectes americanus) on calanoid
copepods
P.A. Shaheen, L.L. Stehlik, C.J. Meise, A.W. Stoner,
J.P. Manderson, D.L. Adams-2001
Journal of Experimental Marine Biology and Ecology,
257 (1): 37-51
Abstract:
Field and laboratory investigations were conducted to
examine feeding by newly settled winter flounder (Pseudopleuronectes
americanus) on two co-occurring calanoid copepods, Eurytemora affinis
and Acartia hudsonica. During the spring, these prey are present when
winter flounder initiate their demersal lifestyle in estuaries of the
northeastern United States. Epibenthic zooplankton were collected
concurrently with winter flounder in the Navesink River estuary, NJ, in May
1998 and 1999. Although both calanoid species were in the estuary during the
2-year survey, E. affinis was consumed nearly to the exclusion of A.
hudsonica by newly settled winter flounder. Annually, E. affinis
and A. hudsonica had similar size distributions in field collections,
indicating that species choice was not size selective. However, when preying
on E. affinis, winter flounder preferred the larger sized organisms.
In single species laboratory experiments, E. affinis and A.
hudsonica were consumed equally by newly settled winter flounder (19--23
mm TL), but there were more strikes made toward E. affinis. Despite
the lower catch efficiency, E. affinis was selected over A.
hudsonica when the prey species were offered together in equal numbers.
The selection for E. affinis over A. hudsonica by newly
settled winter flounder may be the result of behavioral and/or morphological
differences in the prey species.
(Institute of Marine and Coastal Sciences, Rutgers
University, New Brunswick, NJ 08903, USA)