LE3 .A278 1980

1980

Daborn, Graham

Acadia University

Master of Science

Masters

Biology

Biology

The feeding habits of juvenile fish in the southern bight of Minas Basin were studied through gut analyses of fish taken mainly during eight 24-hour seine collections from June 13 -August 6, 1979. Eleven species were examined of which Menidia menidia and Liopsetta putnami were considered resident. Clupea har>engus, Gasterosteus spp. and L. putnami were more common in samples collected during daylight and Anguilla rostrata and Pollachius virens were more abundant in night collections. Feeding activity was correlated with tidal state in only three species; Microgadus tomcod, Gasterosteus spp. and Urophycis tenuis. The patchiness of the food supply and abundance of benthic organisms in the guts suggests that electivity indices, based only upon plankton samples as representation of the potential food supply, are not valid. Diet changed with ontogeny; early juvenile fish fed largely upon the copepod Eurytemora herdmani whereas older juveniles ate organisms (eg. Corophium volutator, Diastylis polita and Crangon septemspinosa) usually associated with the benthos. Such benthic organisms, particularly C. volu-tator, are important elements of the southern bight fish food resources. This area functions as a nursery, feeding and acclimation area for several fish specjes. Production of C. volutator seems to be of vital importance to the higher trophic levels in this system.

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