''Gnatholepis gymnocara'', the Nakedcheek sandgoby, is a small species of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

in the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Gobionellinae The Gobionellinae are a subfamily of fish which was formerly classified in the family Gobiidae, the gobies, but the 5th Edition of ''Fishes of the World'' classifies the subfamily as part of the family Oxudercidae. Members of Gobionellinae mostl ...

. The Naked cheek sandgoby is found primarily in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

along the

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

of Australia .Johnson, J.W., 1999. Annotated checklist of the fishes of Moreton Bay, Queensland, Australia. Memoirs of the Queensland Museum 43(2):709-762.

Description

The "naked cheeks," which serve as the namesake of this species, are one of the most diagnostic features of the Nakedcheek sandgoby. Scales are totally absent on the cheek and operculum, back to the predorsal midline, though there are a few typical

cycloid scale A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scale (zoology), scales, which can also provide effective Underwater camouflage, camouflage through the us ...

s on the base of the pectoral fin and on the breast.Larson, H.K. and D.J. Buckle, 2012. A revision of the goby genus Gnatholepis Bleeker (Teleostei, Gobiidae, Gobionellinae), with description of a new species. Zootaxa 3529:1-69. While a small fold might be present on the end of the lower lip, there is no truly distinct flap on the lower lip, which is also common in other goby species. There are also no teeth with are distinctly larger than the rest of the dentition.

Size and coloration

Males of this species reach a maximum length of 3.7 cm in

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

. Their bodies are pale tan/dusky with a 6 darker dusky blotches, and a row of horizontal spots and streaks. There is also an irregular dark, cross-shaped blotch on each cheek that extends downward from the eye. There is a small brown spot at the base of the

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

that is approximately the width of the pupil. Males also have a small dark spot at the base of the first dorsal fin, while females lack this feature.

Distribution and habitat

The Nakedcheek sandgoby is found in the western

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, specifically

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It can be found in shallow, nearshore marine environments between 0 and 1m in depth. Specimens are typically collected from around 0.5m deep and, while most are found in marine waters, at least one has been collected from a

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

habitat.

References

{{Taxonbar, from=Q3290639 Gobionellinae Marine fish of Eastern Australia Fish described in 2001