Lightfishes | |
---|---|
Ichthyococcus ovatus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Stomiiformes |
Suborder: | Phosichthyoidei |
Family: | Phosichthyidae |
Genera | |
Ichthyococcus | |
Synonyms | |
Photichthyidae |
Lightfishes are small stomiiform fishes in the family Phosichthyidae[1][2]
The earliest fossils of lightfishes are from Oligocene-aged Paratethyan marine strata in the Czech Republic.[3]
They are very small fishes found in oceans throughout the world: most species grow no longer than 10 cm, while those in the genus Vinciguerria only reach 4 cm or so.
They make up for their small size with abundant numbers: Vinciguerria is thought — with the possible exception of Cyclothone — to be the most abundant genus of vertebrates. Deep-sea trawls of the Humboldt Current in the southeast Pacific have found that lightfishes make up 85% by mass of mesopelagic fishes, with Vinciguerria lucetia by far the most numerous species.[4]
They are bioluminescent fishes, possessing rows of photophores along their sides, with which they hunt planktonic invertebrates, especially krill, copepods, and planktonic amphipods.[5]