Reproductive dynamics of two Jasus species in the South Atlantic region

Abstract

Comparisons of egg size, brood size and egg production per lifetime (fecundity per recruit) between Jasus tristani from the Tristan da Cunha group of islands and J. lalandii from the west coast of southern Africa reveal distinct differences. Females of the continental species J. lalandii have smaller eggs, larger brood sizes and a greater fecundity per recruit than the insular species J. tristani. Greater egg production in J. lalandii implies that rates of larval mortality are likely to be higher in this species. A number of possible reasons may be involved — these include differential predation rates on newly hatched and returning larval forms, as well as losses induced by topographic forcing of currents by the Walvis Ridge. © 1991 Taylor & Francis Group, LLC.