Southern Dumpling Squid

Like other bobtail squid, southern dumpling squid have a light organ fuelled by symbiotic bioluminescent bacteria. The light organ, which is butterfly-shaped, is situated in the mantle cavity and is used to cancel out the bobtail squid's silhouette. There are large semi-circular fins on the rear half of the mantle. Although they can change colour, they are usually an iridescent green or yellow with brown spots. The bobtail squid have four rows of suckers on each arm and both their arms and tentacles are armed with toothed horny rim.

Like many cephalopods the male can be distinguished from the female by an enlarged hectocotylus which occurs as the first left arm. Females lay 2 or 3 batches of round creamy orange eggs (25 – 170 eggs per batch) over a few weeks towards the end of their life. Females die between a week and a fortnight after laying eggs and males die a short time after mating multiple times. Females mate with many partners and may use the sperm of more than one partner for one batch of eggs. Depending on temperature incubation can take up to four and a half months, because of this the eggs must be comparatively large to provide enough yolk for successful embryonic development. If the females are underfed while producing eggs they tend to produce fewer and smaller eggs which leads to high embryo mortality rates.