Dolphin caught by charter boats fishing over the Continental Shelf in 1961-63 were examined to determine food habits and sex ratios. Most important prey (listed according to percent of total prey weight) were: Exocoetidae (26%), Scombridae (22%), Carangidae(12%), Balistidae (9%), and Coryphaenidae (5%). Males constituted a significant majority (61%) of large dophin (801-1,275 mm fork length). Most (71%) small dolphin (450400 mm) were females. Large dolphin of both sexes were generally captured in open water, while small female dolphin were usually associated with fidedines (areas where current patterns cause accumulations of floating Sargassum and other flotsam). In 1963, tidedines were infrequently encountered by charter boats. Decreased charter boat catches, increased abundance of young males in the fishery, and impaired foraging by small female dolphin resulted. We hypothesize that male dolphin (which are heavier than females of similar length) leave the sanctuary of the tidedine at an earlier age than females to forage for large prey in the open ocean. Thus, most small dolphin captured near tide-lines and associated flotsam are females. Most large dolphin captured by trolling are males, because their significantly greater weight per unit of length results in more voracious feeding and increased selection by the charter boat fishery.

A synopsis of the biology of the red porgy, Pagrus pagrus, that includes taxonomy, morphology, distribution, aspects of the life history, behavior, and abundance. Also included are: discussions of commercial and recreational fishing methods and fishing grounds, and size, age, and sex composition of the recreational catch off North Carolina and South Carolina and commercial catch off Argentina. 'Austin, H. M. 1971. Ecology of fishes on Florida's Middle Ground.

The validity of age determinations from scales of dolphin (Coryphaena hippurus) captured off the North Carolina coast is established. Specimens were obtained from the local charter boat fishery. The greatest age of dolphin examined was 3 years. None of the 3‐year‐old fish and few of the 2‐year‐old fish were females. Predominance of males in age‐groups II and III is believed to be caused by differential feeding habits of the sexes. Analysis of stomach contents indicates that older males may be more voracious feeders than older females; and, therefore, are more susceptible to capture by the hook‐and‐line fishery. Males are heavier than females throughout their complete length range. The body‐scale relation is efficiently described by linear regression. Theoretical fish length at the time of scale formation was 93.75 mm. Growth in length of male and female dolphin was not significantly different. Rate of growth was independent of year of collection. Length at time of first annular formation was 653 mm. Annual increments were 271 mm during the 2nd year, and 263 mm during the 3rd year.

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