Animal Species:Southern Ocean Sunfish, Mola ramsayi (Giglioli, 1883)
The Southern Ocean Sunfish is a huge round-bodied fish that is sometimes seen 'basking' on the water surface in southern Australian waters.
A Southern Ocean Sunfish on the surface
B. & J. Carter
© B. & J. Carter
Identification
The Southern Ocean Sunfish is a deep bodied species with high dorsal and anal fins placed posteriorly on the body. It has a small mouth with teeth fused into a parrot-like beak. The skin is leathery with rough denticles. Large fish have a ridge above and behind the eyes.
This fish is brown to grey above often with pale blotches, and paler below. After death it becomes white.
Four species of sunfish are found in Australian waters, the Southern Ocean Sunfish, Ocean Sunfish, Mola mola, Slender Sunfish, Ranzania laevis, and the Point-tailed Sunfish, Masturus lanceolatus. The two species of Mola can be separated by the number of ossicles in the clavus (the tail frill). M.ramsayi has 12 ossicles that are wider than the spaces between them. M.mola has 8 to 9 ossicles that are narrower than the spaces between them. There is a distinct band of smaller denticles at the base of the clavus in M.mola that is lacking in M.ramsayi.
Size range
The species grows to 3.3 m in length.
Similar Species
Ocean Sunfish, Sharptail Sunfish
Distribution
It occurs in oceanic waters of the South Pacific Ocean.
In Australia it is found in temperate marine waters from northern New South Wales, around the south of the country, including Tasmania, to south-western Western Australia.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.
Distribution by collection data
Ozcam map of Southern Ocean Sunfish specimens in the Australian Museum.
Classification
- Species:
- ramsayi
- Genus:
- Mola
- Family:
- Molidae
- Order:
- Tetraodontiformes
- Class:
- Actinopterygii
- Subphylum:
- Vertebrata
- Phylum:
- Chordata
- Kingdom:
- Animalia
References
- Glover, C.J.M. in Gomon, M.F., Glover, C.J.M. & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
- Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
- Hutchins, B. & M. Thompson. 1983. The Marine and Estuarine Fishes of South-western Australia. Western Australian Museum. Pp. 103.
- Thys, T.M. et al. 2013. First record of the southern ocean sunfish, Mola ramsayi, in the Galapagos Marine Reserve. Marine Biodiversity Records. DOI:10.1017/S175526723000377. Vol 6.
- Last, P.R., E.O.G. Scott & F.H. Talbot. 1983. Fishes of Tasmania. Tasmanian Fisheries Development Authority. Pp. 563.
Mark McGrouther
, Collection Manager, Ichthyology
Last Updated:
Tags fishes, ichthyology, Southern Ocean Sunfish, Mola ramsayi, Molidae, brown, grey, odd-shaped, round, > 2 m, countershaded, pelagic, marine, adult, long fin rays,
