Distribution, size and sex composition, reproductive biology and diet of sharks from Northern Australia

摘要: The distribution, size composition, sex ratio, reproductive biology and diet of 17 species shark from the families Triakidae, Hemigaleidae Carcharhinidae northern Australia were examined. In most these ratio embryos is 1 : 1, whereas in post-partum populations there significantly more males than females. results indicate four broad strategies among sharks. reproduction was distinctly seasonal with individual females giving birth each Austral summer (annual cycle) after a gestation period 9-12 months. A second group had very similar cycle except that gave every year (biennial cycle). third an annual but breeding continuous throughout year, mostly small bottom-associated One twice (biannual 6-month gestation. average at varied 27 to 75 cm litter 2 34. about 40% maturity, which turn 70% maximum size. Diets ranged omnivorous highly selective. Fish important component all one species. There evidence partitioning food resources sympatric, morphologically similar,