Life History Traits of Two Allopatric Clupeids, Atlantic Menhaden and Gulf Menhaden, and the Effects of Harvesting on These Traits

Abstract

Abstract Life history traits of Atlantic menhaden Brevoortia tyrannus and gulf menhaden B. patronus were compared and interpreted within the context of a bet-hedging model that predicts what traits should evolve in local environments when the survival of the larval stage is less predictable than that of the adult stage. Atlantic menhaden appear to spawn in a relatively less-predictable environment. Compared with gulf menhaden, Atlantic menhaden are older at the onset of sexual maturity and have a longer reproductive span, as well as a longer spawning period. Atlantic menhaden produce larger eggs, and their larvae are larger at hatching and younger and larger at first feeding; the larvae appear to grow faster but they are relatively smaller than gulf menhaden at their first metamorphosis. Heavy exploitation of Atlantic menhaden has resulted in a truncation of the age structure, contraction of their spawning range, a reduction in lifetime fecundity, and possibly modifications of the egg size distribution. T...