Demographic analyses are useful in fishery management, but they require valid estimates of age-specific mortality and natality rates, as well as data on the distribution, abundance, habits and reproduction of the population. In California, reliable age-specific estimates growth, mortality, maturity, and fecundity are available only for the leopard shark, Triakis semifasciata . If the present fishing pressure is included in the survivorship function, R o and 'r' are reduced considerably, especially if leopard sharks first enter the fishery at early ages. Department of Ichthyology, Montpellier II University, France. 2.Halieutic Department, National Agronomic Instutute of Tunis, Tunisia.
Females are larger than males.
Gestation takes place during six months or more. There is probably one reproductive cycle per year. Woods Hole, MA 02543. Comparison of swimming speeds from telemetry with speed of travel from tag returns suggests that the sharks make use of favorable ocean currents in their movements. Telemetry experiments in the Gulf Stream and eddys south of New England appear to show instances of such use of currents.