Spongiobranchaea australis is a species of sea angel, a form of sea-slug plankton. It has a partially transparent body with small "wings" that it uses to swim in its habitat. It is classified as a pteropod.
Spongiobranchaea australis is found in austral waters near the Antarctic region, in the southern hemisphere. The species is primarily concentrated in areas near Australia and New Zealand. The areas they live in is pelagic and temperate; 2 ðC - 13 ðC.
The average size was recorded to be 22 mm. Regular sexually active males and females vary around 3âÂÂ5 mm. The largest ever individual was found to be 2.2 cm.