Greeneyes are deep-sea aulopiform

Aulopiformes

Aulopiformes is an 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 used for this group...

 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 language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 words chloros meaning "green" and ophthalmos meaning "eye".

Some species are of interest to commercial and subsistence fisheries

Fishery

Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

; the fish are made into fish meal

Fish meal

Fish meal, or fishmeal, is a commercial product made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake obtained by rendering pressing the cooked whole fish or fish trimmings to remove most of the fish oil and water, and then ground...

 or sold fresh.

Physical description

Aptly named after their disproportionately large, iridescent

Iridescence

Iridescence is generally known as the property of certain surfaces which appear to change color as the angle of view or the angle of illumination changes...

 (as well as fluorescent) eyes, greeneyes are slender fish with slightly compressed bodies. The largest species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, the Shortnose greeneye (Chlorophthalmus agassizi) reaches a length of 40 centimetres (15.7 in), but most other species are much smaller. Their heads are small with large jaws. The 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 the head

Behaviour and reproduction

Greeneyes are generally deepwater fish, found from 50 metres (164 ft) down to about 1000 metres (3,280.8 ft). They seem to prefer the continental slopes and shelves

Continental shelf

The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...

, possibly forming schools. Greeneyes are known to primarily feed on benthic

Benthos

Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.Many organisms...

 invertebrates, as well as pelagic

Pelagic zone

Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...

 crustaceans such as decapods

Decapoda

The decapods or Decapoda are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are scavengers. It is estimated that the order contains nearly 15,000 species in around 2,700 genera, with...

 and mysids.

Like many aulopiform fish, greeneyes are hermaphroditic

Hermaphrodite

In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

; 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

Larva

A larva 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...

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

Hake

The term hake refers to fish in either of:* family Phycidae of the northern oceans* family Merlucciidae of the southern oceans-Hake fish:...

 are known predators of greeneyes.

Classification

The genus Bathysauroides is sometimes classified with the greeneyes, but this article follows FishBase

FishBase

FishBase is a comprehensive database of information about fish species . It is the largest and most extensively accessed online database on adult finfish on the web...

 in placing it in its own family, Bathysauroididae.

There are 18 species in two genera:

• Genus Chlorophthalmus
  • Chlorophthalmus acutifrons Hiyama, 1940.
  • Shortnose greeneye, Chlorophthalmus agassizi Bonaparte, 1840.
    
  • Chlorophthalmus albatrossis Jordan
    David Starr Jordan
    David Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
    
     & Starks, 1904.
  • Atlantic greeneye, Chlorophthalmus atlanticus Poll, 1953.
  • Spinyjaw greeneye, Chlorophthalmus bicornis Norman, 1939.
  • Chlorophthalmus borealis Kuronuma & Yamaguchi, 1941.
  • Chlorophthalmus brasiliensis Mead, 1958.
  • Chlorophthalmus chalybeius (Goode, 1881).
    
  • Chlorophthalmus corniger Alcock
    Alfred William Alcock
    Alfred William Alcock was a British physician naturalist and carcinologist.Alcock was the son of a sea-captain, John Alcock in Bombay, India who retired to live in Blackheath...
    
    , 1894.
  • Chlorophthalmus ichthyandri Kotlyar & Parin, 1986.
  • Chlorophthalmus mento Garman, 1899.
  • Chlorophthalmus nigromarginatus Kamohara, 1953.
  • Chlorophthalmus pectoralis Okamura & Doi, 1984.
  • Chlorophthalmus proridens Gilbert & Cramer, 1897.
  • Spotted greeneye, Chlorophthalmus punctatus Gilchrist, 1904.
  • Chlorophthalmus zvezdae Kotlyar & Parin, 1986.
• Genus Parasudis
  • Parasudis fraserbrunneri (Poll, 1953).
  • Longnose greeneye, Parasudis truculenta (Goode & Bean, 1896).