Reproductive Biology & Genetics

A series of field observations suggest that group reproductive behaviour and polyandrous copulations by females in a single mating event may be common in some sharks. Here, I employ paternity analyses using bi-parentally inherited microsatellite markers to test for the presence or absence of multiple paternity (MP, where a single litter is sired by multiple males) in shark litters and ascribed the presence of the former to a polyandrous mating system (where females mate with multiple males in a single breeding season).

Although, it is well known that long-term sperm storage across breeding seasons can also result in MP without polyandrous behaviour within a single breeding season. So, to place the genetic results in a broader context, by assimilating biological data, I use histologic approaches to assess for the presence of sperm storage in the female shark reproductive tracts. This work is done in collaboration with fishery scientist at DAFF who provide specimens and dissection facilities