Box jellyfish
Although the notoriously dangerous species of box jellyfish are largely restricted to the tropical Indo-Pacific region, various species of box jellyfish can be found widely in tropical and subtropical oceans, including the Atlantic Ocean and the east Pacific Ocean, with species as far north as California ("Carybdea confusa"), the Mediterranean Sea ("Carybdea marsupialis") and Japan (such as "Chironex yamaguchii"), and as far south as South Africa (for example, "Carybdea branchi") and New Zealand (such as "Copula sivickisi").
Morbakka virulenta
In common with other jellyfish in the class Cuboza, "Morbakka virulenta" has a box-like shape. It has rabbit like rhopaliar horns and closely resembles its close relative from Australia, "Morbakka fenneri". "M. virulenta" is one of the largest species of box jellyfish, with tentacle lengths of about three metres at maximum extension. The maximum bell height observed in "M. virulenta" can range up to 250 mm and the bell width can range up to 200 mm. The bell of "M. virulenta" is rectangle-shaped and covered with nematocyst warts. "Morbakka virulenta" can be distinguished from other species in the family by its heavily branched velarial canals as well as two rows of perradial warts with additional scattered warts.