The white-eye, Oxyzygonectes dovii, is a 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...

 of killifish

Killifish

A killifish is any of various oviparous cyprinodontiform fish . Altogether, there are some 1270 different species of killifish, the biggest family being Rivulidae, containing more than 320 species...

 of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Anablepidae

Anablepidae

Anablepidae is a family of freshwater and brackish water fishes living on river estuaries from southern Mexico to southern South America. There are three genera with sixteen species: the four-eyed fishes , the onesided livebearers and the white-eye, Oxyzygonectes dovii...

. This species is the only member of its genus Oxyzygonectes and the subfamily Oxyzygonectinae.

This fish species is found in Pacific drainages in Nicaragua

Nicaragua

Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...

, Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

, and Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

.

O. dovii has no gonopodium like the other members of its family. The dorsal and anal fins are posteriorly placed just before the caudal peduncle and well behind the midbody. The reach a maximum length of about 15 centimetres (6 in) TL

Fish measurement

Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

.

Many of these fish inhabit brackish waters. They are found in rivers of low elevation

Elevation

The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

, up to 15 metres (50 ft) above sea level

Sea level

Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

. These fish feed on detritus, algae, and sometimes on terrestrial insects.

Though it occurs in estuaries, it breeds in freshwater. This species is not a seasonal killifish. O. dovii has been bred in captivity.