Spatial and temporal feeding patterns and dietary resource utilization of the sand flounder, Scophthalmus aquosus (Mitchill), from the inner New York Bight.
Item
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Title
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Spatial and temporal feeding patterns and dietary resource utilization of the sand flounder, Scophthalmus aquosus (Mitchill), from the inner New York Bight.
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Identifier
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AAI9020818
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identifier
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9020818
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Creator
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Warkentine, Barbara Ellen.
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Contributor
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Adviser: Joseph W. Rachlin
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Date
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1990
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, General | Biology, Ecology | Biology, Zoology | Agriculture, Fisheries and Aquaculture
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Abstract
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To determine the dietary resource utilization for resident populations of the sand flounder of the New York Bight a series of stations, covering a span of 133.3 km, was established along the Bight's western arm. These stations extended from Absecon Inlet, N.J. in the south to Breezy Point, N.Y. in the north. The stations were sampled during June and November of 1984, April and July of 1985, and January 1986. This schedule allowed for the establishment of a sampling protocol designed to gain information on the spatial and temporal feeding patterns of this species.;Analysis revealed that the mysid shrimp, Neomysis americana, accounted for greater than 90% of the sand flounder's diet throughout the sampling range and during all seasons except January 1986. During January the dominant prey consumed was the mysid Mysidopsis bigelowi. Other important, but not dominant, food items consisted of sand shrimps, amphipods, nematodes, crabs and crab larvae, isopods, polychaetes and fish. Application of the Manly preference index and the electivity index of Vanderploeg and Scavia determined that mysids were the preferred food item for this fish throughout its range and over all sampling seasons.;The resident sand flounder co-occurs, in this region with seasonally migrating flatfishes, i.e. the winter, summer, fourspot, smallmouth, and yellowtail flounder. A working hypothesis that the diet of the sand flounder would change as these other flatfish move into and out of its region was tested. This hypothesis was falsified. Mysids remained the dominantly preferred food item taken by the sand flounder regardless of the presence of other potentially competing flatfish in its foraging field. Although a seasonal difference in consumed mysids was observed this difference was found to reflect a seasonal change in the dominance of the species representing the mysid fauna rather than interspecific interactions between co-occurring flat fish. Further, these fish were found to have very little dietary overlap. There appears to be very little dietary competition between sand flounders and other co-occurring flatfish.;Ontogenetic dietary shifting was not observed for the sand flounder. Size classes of sand flounders examined in this study ranged from 3.0 to 27.0 cm standard length and all fish fed dominantly on small crustaceans; thus, no evidence of dietary gape-limitation was found.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
