The Synodontidae or lizardfishes
[(or typical lizardfish to distinguish them from the Bathysauridae and Pseudotrichonotidae)] 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 the Ancient Greek word (), meaning "the depths". ...
(bottom-dwelling) marine and estuarine bony fishes that belong to the
aulopiform 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
Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...
s. The
dorsal fin
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...
is located in the middle of the back, and accompanied by a small
adipose 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 b ...
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 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 environm ...
. They prefer sandy environments, and typically have body colours that help to camouflage them in such environments.[
The ]larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
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.Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
-aged London Clay
The London Clay Formation is a Sediment#Shores and shallow seas, marine formation (geology), geological formation of Ypresian (early Eocene Epoch, c. 54-50 million years ago) age which outcrop, crops out in the southeast of England. The London C ...
formation.
See also
* Bombay duck
* Deepsea lizardfish
* USS ''Lizardfish'' (a US submarine)
Notes
References
{{Authority control
Aulopiformes families
Taxa named by Theodore Gill