The Synodontidae or lizardfishes(or typical lizardfish to distinguish them from the

Bathysauridae The Bathysauridae are a small family of deepwater aulopiform fish, related to the telescopefishes. The two species in the family both belong to the genus ''Bathysaurus''. Commonly called deepwater lizardfishes or deepsea lizardfishes, the latter ...

and

Pseudotrichonotidae ''Pseudotrichonotus'' is a genus of fish in the family Pseudotrichonotidae native to the Indian Ocean, Indian and Pacific Ocean. This genus is the only member of its family (biology), family. Species There are currently 4 recognized species in t ...

) are

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

(bottom-dwelling) marine and estuarine bony fishes that belong to the

aulopiform Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes ...

fish order, a diverse group of marine ray-finned fish consisting of some 15 extant and several prehistoric families. They are found in tropical and subtropical marine waters throughout the world. Lizardfishes are generally small, although the largest species measures about in length. They have slender, somewhat cylindrical bodies, and heads that superficially resemble those of

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s. The

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

is located in the middle of the back, and accompanied by a small

adipose fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...

placed closer to the tail. They have mouths full of sharp teeth, even on the tongue. Lizardfishes are benthic animals that live in shallow coastal waters; even the deepest-dwelling species of lizardfish live in waters no more than deep. Some species in the subfamily

Harpadontinae The Harpadontinae are a subfamily of lizardfishes in the family Synodontidae. It comprises two genera: *''Harpadon'' *''Saurida ''Saurida'' is a genus of fish in the family Synodontidae. Species There are currently 23 recognized species in ...

live in

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 ...

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

. They prefer sandy environments, and typically have body colours that help to camouflage them in such environments. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e of lizardfishes are free-swimming. They are distinguished by the presence of black blotches in their guts, clearly visible through their transparent, scaleless skin.

Taxonomy

Three genera of the Synodontidae are known to inhabit the western Atlantic, including ''Synodus'', represented by six species, ''Saurida'', represented by four species, and ''Trachinocephalus'', represented by a single species. The six species comprising the genus ''Synodus'' are '' S. intermedius'', '' S. saurus'', '' S. synodus'', '' S. foetens'', ''S. bondi'', and '' S. macrostigmus''. The four species comprising the genus ''Saurida'' are '' S. umeyoshii'', '' S. pseudotumbil'', '' S. undosquamis'', and '' S. tumbil''. The single species of ''Trachinocephalus'' is ''T. myops''. The extinct ''

Argillichthys ''Argillichthys toombsi'' is an extinct lizardfish from the Ypresian-aged London Clay Formation from Lower Eocene England. It is known from a skull. See also Other notable extinct Cenozoic aulopiforms include: *''Alepisaurus paronai'', an ex ...

'' is represented only by a single species, ''A. toombsi'', from the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

-aged

London Clay The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from t ...

formation.

Notes

References

{{Taxonbar, from=Q854803 Ray-finned fish families Taxa named by Theodore Gill