Greeneyes are deep-sea aulopiform marine fishes in the small family Chlorophthalmidae. Thought to have a circumglobal distribution in tropical and temperate waters, the family contains just 18 species in two genera. The family name Chlorophthalmidae derives from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

words ''chloros'' meaning "green" and ''ophthalmos'' meaning "eye". Some species are of interest to commercial and subsistence

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...

; the fish are made into

fish meal Fish meal (sometimes spelled fishmeal) is a commercial product made from whole wild-caught fish, bycatch, and fish by-products to feed farm animals, such as pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish ...

or sold fresh. The earliest known member of the group is '' Acrognathus'' from the

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

. Another potential fossil genus, '' Iniomus'', is known from the

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

of California.

Description

Aptly named after their disproportionately large,

iridescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes. Iridescence is caused by wave interference of light in microstruc ...

(as well as

fluorescent Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ...

) eyes, greeneyes are slender fish with slightly compressed bodies. The largest

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

, the Shortnose greeneye ('' Chlorophthalmus agassizi'') reaches a length of , but most other species are much smaller. Their heads are small with large jaws. Their coloration ranges from a yellowish to blackish brown, and some species have cryptic blotches. Their fins are simple and spineless; aside from their eyes, some species also have iridescent patches covering their heads.

Behaviour and reproduction

Greeneyes are generally deepwater fish, found from . They seem to prefer the

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margi ...

s and shelves, possibly forming schools. Greeneyes are known to primarily feed on

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". ...

invertebrates, as well as

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

crustaceans such as

decapods The Decapoda or decapods, from Ancient Greek δεκάς (''dekás''), meaning "ten", and πούς (''poús''), meaning "foot", is a large order (biology), order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfis ...

and

mysid Mysida is an order of small, shrimp-like crustaceans in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch or "marsupium" in females. The fact that the larvae are reared in thi ...

s. Like many aulopiform fish, greeneyes are

hermaphroditic A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

; this is thought to be a great advantage in deep-sea habitats, where the chances of running into a compatible mate are uncertain. Young and

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 ...

l greeneyes are pelagic rather than benthic, staying within the upper levels of the water column.

Hake Hake is the common name for fish in the Merlucciidae family of the northern and southern oceans and the Phycidae family of the northern oceans. Hake is a commercially important fish in the same taxonomic order, Gadiformes, as cod and haddo ...

are known predators of greeneyes.

Classification

The genus ''

Bathysauroides ''Bathysauroides gigas'', the pale deepsea lizardfish, is the only species in the family Bathysauroididae. This species is found in the western Pacific Ocean where it is so far only known from the waters around Japan and Australia. This species ...

'' is sometimes classified with the greeneyes, but this article follows

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

in placing it in its own family, Bathysauroididae.

References

* {{Taxonbar, from=Q548754 Taxa named by David Starr Jordan