Oxyeleotris expatria
Encyclopedia
Oxyeleotris expatria is a freshwater
sleeper goby from the family Eleotridae
. It is endemic to a single lake
in the Philippines
.
s, the first one supported by spines. The caudal fin is truncately-shaped, usually not much thicker than the peduncle itself. Its eyes are located dorsally, another trait commonly seen in benthic fish.
in the Philippines. Lake Manguao is a freshwater lake located in the hilly areas in the northern part of the Philippine island of Palawan
. The lake has at least four brooks draining into it, yet it has no rivers draining out from it. O. expatriata shares the lake with at least two other endemic species of fish from the family Cyprinidae.
, there have been extremely few studies on this species. The few ones that have been done describe the fish as a benthic species, spending much of its time resting on the lake's bottom. Despite its size, O. expatriata is predatory, known to feed mostly on the small crustaceans that make the lake's muddy bottom their home. It has also been known to ingest small fishes.
Tilapia
, a fish known for disrupting and destroying the natural balance of the ecosystems it invades, was introduced into the lake in 1992. The presence of this voracious species may drive O. expatria into extinction.
to describe the fish as an expatriate
.
Oxyeleotris expatria was originally described by Herre as Boroda expatria. Boroda was derived from the Visayan word borod, which was used by the natives of the lake to refer to goby-like fishes. The name remained until 1997 when it was redesignated into the genus Bostrychus (as Bostrychus expatria) by Eschmeyer. The species has since been properly moved into the genus Oxyeleotris
, which remains its valid name today.
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
sleeper goby from the family Eleotridae
Eleotridae
Sleeper gobies are members of the Eleotridae fish family, found predominantly in the tropical Indo-Pacific. There are approximately 35 genera and 150 species. While many eleotrids pass through a planktonic stage in the sea and some spend their entire lives in the sea, as adults the majority live in...
. It is endemic to a single lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
.
Anatomy and morphology
Oxyeleotris expatria is a small fish, growing only a mere 14cm in length. They appear as standard members of their family, with non-hydrodynamically-shaped bodies typical of bottom-dwelling fish. It possesses two completely separate dorsal finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s, the first one supported by spines. The caudal fin is truncately-shaped, usually not much thicker than the peduncle itself. Its eyes are located dorsally, another trait commonly seen in benthic fish.
Range and distribution
Oxyeleotris expatria has a single known population that can be found only in Lake ManguaoLake Manguao
Lake Manguao is a lake located in the Northernmost region of the island of Palawan in the Philippines. It harbors several endemic species of fish, such as the goby Oxyeleotris expatria....
in the Philippines. Lake Manguao is a freshwater lake located in the hilly areas in the northern part of the Philippine island of Palawan
Palawan
Palawan is an island province of the Philippines located in the MIMAROPA region or Region 4. Its capital is Puerto Princesa City, and it is the largest province in the country in terms of total area of jurisdiction. The islands of Palawan stretch from Mindoro in the northeast to Borneo in the...
. The lake has at least four brooks draining into it, yet it has no rivers draining out from it. O. expatriata shares the lake with at least two other endemic species of fish from the family Cyprinidae.
Ecology
Owing to the remoteness of its habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
, there have been extremely few studies on this species. The few ones that have been done describe the fish as a benthic species, spending much of its time resting on the lake's bottom. Despite its size, O. expatriata is predatory, known to feed mostly on the small crustaceans that make the lake's muddy bottom their home. It has also been known to ingest small fishes.
Importance to humans
As a small freshwater fish in an island with rich marine resources, O. expatria has no known commercial value. The fish may be caught as bycatch by small cast nets as fishing in the lake is done by the local population. It is known as bulokot by the natives living around the lake.Conservation
In 1996, the World Conservation Monitoring Centre assessed the fauna of Lake Manguao and O. expatria (as Boroda expatria) was classified as VULNERABLE. As O. expatria has one known population in a single freshwater lake, its fate is inextricably tied to its home lake's. The fish population is extremely vulnerable to anthropogenic disturbance such as pollution and overfishing, and a slight disturbance to the balance of the lake could send the species to extinction. In theory, the entire island of Palawan has been declared a wildlife preserve which should ensure the survival of the species, but wildlife laws are rarely enforced or followed in the country.Tilapia
Tilapia
Tilapia , is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats, including shallow streams, ponds, rivers and lakes. Historically, they have been of major importance in artisan fishing in Africa and the...
, a fish known for disrupting and destroying the natural balance of the ecosystems it invades, was introduced into the lake in 1992. The presence of this voracious species may drive O. expatria into extinction.
Etymology and taxonomic history
The genus name, Oxyeleotris is derived from its two component words, oxys which is Greek for "sharp", and eleotris which is the name of a fish found in the Nile River. The species name, expatria was originally chosen by HerreAlbert William Herre
Albert William Christian Theodore Herre was an American ichthyologist and lichenologist.Herre was born in 1868 in Toledo, Ohio....
to describe the fish as an expatriate
Expatriate
An expatriate is a person temporarily or permanently residing in a country and culture other than that of the person's upbringing...
.
Oxyeleotris expatria was originally described by Herre as Boroda expatria. Boroda was derived from the Visayan word borod, which was used by the natives of the lake to refer to goby-like fishes. The name remained until 1997 when it was redesignated into the genus Bostrychus (as Bostrychus expatria) by Eschmeyer. The species has since been properly moved into the genus Oxyeleotris
Oxyeleotris
Oxyeleotris is a genus of fish in the Eleotridae family.It contains the following four species:* Fimbriate gudgeon * Paniai gudgeon * Sleepy cod...
, which remains its valid name today.