Construction and test of an artificial uterus for ex situ development of shark embryos

Abstract

An artificial uterus (AU) was constructed from clear and opaque acrylic and life-support and monitoring systems were attached. The dwarf ornate wobbegong shark (Orectolobus ornatus) was used to test the AU because recent research has shown that during pregnancy the uterine fluid composition changes with mid- to late-term embryos immersed in seawater. An artificial uterine fluid comprising filtered, autoclaved seawater was placed in the AU. Eight, sexually mature female O. ornatus were captured from the wild and held in captivity. Subsequent ultrasound examinations confirmed pregnancy in three of these females. Six late-term embryos (three males and three females) were removed surgically from one euthanized female and placed in the AU. Their condition was monitored for 18 days before "birth" on September 26, 2008. The subsequent survival and growth of the AU pups was compared with naturally born wobbegong pups in captivity over a 140-day monitoring period. The development in the AU did not have detrimental effects as there was no postpartum mortality and there were marked increases in total length and weight that did not differ significantly between the two groups.