Retropinnidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of bony fish that contains the southern hemisphere smelts and graylings. They are quite closely related to the northern smelts (Osmeridae), which they greatly resemble, but not to the northern graylings (Thymallus). Species from this family are only found in southeastern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

. Although a few species are partly marine

Saline water

Saline water is a general term for water that contains a significant concentration of dissolved salts . The concentration is usually expressed in parts per million of salt....

, most inhabit fresh

Fresh Water

Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...

 or brackish water

Brackish water

Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...

.

Genera and species

There are just six species, grouped into three genera:

Family Retropinnidae

• Genus Prototroctes
  • Australian grayling
    Australian grayling
    The Australian grayling is a primarily freshwater fish found in coastal rivers in Tasmania and south-eastern Australia. In past decades it has also been known as the “cucumber mullet” or “cucumber herring,” for its cucumber-like odor.-Description and Diet:The Australian grayling is a streamlined...
    
    , Prototroctes maraena Günther, 1864.
  • New Zealand grayling
    New Zealand grayling
    The New Zealand grayling, Prototroctes oxyrhynchus, is an extinct smelt of the genus Prototroctes, which was found only in lowland rivers and streams of New Zealand. Their length was between 20 and 40 cm....
    
    , Prototroctes oxyrhynchus Günther, 1870.
• Genus Retropinna
  • New Zealand smelt
    New Zealand smelt
    The New Zealand smelt, New Zealand common smelt, or New Zealand cucumber fish, Retropinna retropinna, is a smelt of the family Retropinnidae, found only in New Zealand at shallow depths in estuaries and rivers...
    
    , Retropinna retropinna (Richardson
    John Richardson (naturalist)
    Sir John Richardson was a Scottish naval surgeon, naturalist and arctic explorer.Richardson was born at Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of...
    
    , 1848).
  • Australian smelt
    Australian smelt
    Australian smelt, Retropinna semoni, is a small, pelagic silvery freshwater fish found in large numbers in waters of the south eastern Australian mainland.-Distribution:Widely distributed through the south eastern part of the Australian mainland...
    
    , Retropinna semoni (Weber, 1895).
  • Tasmanian smelt
    Tasmanian smelt
    The Tasmanian smelt, Retropinna tasmanica, is a small, pelagic freshwater smelt found in lowland streams of Tasmania, Australia....
    
    , Retropinna tasmanica McCulloch, 1920.
• Genus Stokellia
  • Stokell's smelt
    Stokell's smelt
    Stokell's smelt, Stokellia anisodon, is a smelt, the only member of the genus Stokellia, found in rivers between the Waiau and Waitaki Rivers on the east coast of the South Island of New Zealand. Their length is between 7 and 9 cm.-References:...
    
    , Stokellia anisodon (Stokell, 1941).