Spongiobranchaea australis
Spongiobranchaea australis is a small sea slug called a sea angel. It has a partly transparent body and tiny wing-like fins it uses to swim. This species is a pteropod, living in the open ocean.
Where it lives: in southern ocean waters near Antarctica, especially around Australia and New Zealand. It prefers temperate, pelagic waters about 2–13 °C.
Size: the average length is about 22 mm (2.2 cm), with the largest recorded individual around 2.2 cm. Sexually mature males and females are typically around 3–5 mm in some observations.
This page was last edited on 3 February 2026, at 08:13 (CET).