The slender sunfish (Ranzania laevis) is a mola of the family Molidae, the only extant member of the genus Ranzania,[2] found globally in tropical and temperate seas.

[3][4] The first South Australian specimen was found at Aldinga in 1944.

[6] Several other individuals have stranded in South Australia at Port Willunga, Netley[7] and West Beach with the latter successfully returned live to deeper water.

[8] In contrast to its much larger relatives in the family Molidae, who are very slow-moving and mostly feed upon jellyfish, salps, and small fish and crustaceans, the slender sunfish is known to mainly feed upon squid, particularly of the family Ommastrephidae, which are known for being very fast-moving, displaying evidence that the slender sunfish itself is a faster-moving and agile predator of squid.

The first record of slender sunfish, Ranzania laevis from the Red Sea.