The blind swamp eel (''Ophisternon infernale'') is a species of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the family

Synbranchidae The swamp eels (also written "swamp-eels") are a family (Synbranchidae) of freshwater eel-like fishes of the tropics and subtropics. Most species are able to breathe air and typically live in marshes, ponds and damp places, sometimes burying the ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

where it lives in cave systems and is known in

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

as the '. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has rated this

cavefish Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, Troglomorphism, troglomorphic fish, troglobitic fish, stygobitic fish, phreat ...

as "

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

Taxonomy

The blind swamp eel was first described by the American

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

Carl Leavitt Hubbs Carl Leavitt Hubbs (October 19, 1894 – June 30, 1979) was an American ichthyologist. Biography Early life Carl Leavitt Hubbs was born in Williams, Arizona, to Charles Leavitt and Elizabeth () Hubbs. His father had a wide variety of jobs (far ...

in 1938, the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

having been collected two years earlier by A.S.Pearse. Hubbs named the fish ''Pluto infernalis'' because he liked to associate creatures living underground with the devil, who supposedly dwelt underground, and gave diabolical names to cave fishes; ''infernale'' comes from the Latin for

Hell In religion and folklore, hell is a location or state in the afterlife in which souls are subjected to punishment after death. Religions with a linear divine history sometimes depict hells as eternal destinations, such as Christianity and I ...

. The fish was later transferred to the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Ophisternon ''Ophisternon'' is a genus of swamp eels found in fresh and brackish waters in South and Southeast Asia, New Guinea, Australia, Middle America and West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. Th ...

'', the swamp eels. The genus name is derived from the Greek, "ophis", meaning a serpent, and "sternon", meaning chest. Synonyms for this species include ''Furmastix infernalis'' and ''Synbranchus infernalis''.

Description

The blind swamp eel is an elongated, wormlike fish with no pigment, no scales and no visible eyes. It seems likely that it is derived from the

marbled swamp eel ''Synbranchus marmoratus'', the marbled swamp eel, neotropical swamp eel, marmorated swamp eel, mottled swamp eel, zange, or muçum is a species of swamp eel native to Central and South America, including the island of Trinidad and Grenada. De ...

(''Synbranchus marmoratus'') and became adapted for life underground. It grows to a

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of and the bulbous head bears numerous sensory pores.

Distribution

The blind swamp eel is endemic to the

Yucatán Peninsula The Yucatán Peninsula ( , ; ) is a large peninsula in southeast Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north and west of the peninsula from the C ...

in Mexico where it inhabits freshwater in sinkholes and limestone caves. It lives in shallow water in the muddy substrate or under stones. It has only been found in 7% of the caves investigated, and where it is found, it coexists with the Mexican blind brotula (''Typhliasina pearsei''), and often with the catfish ''

Rhamdia guatemalensis ''Rhamdia'' is a genus of three-barbeled catfishes found in Mexico, Central and South America. These catfishes are nocturnal, opportunistic carnivores, found in a wide range of freshwater habitats. This genus includes a number of troglobitic m ...

''.

Ecology

The blind swamp eel feeds on the faeces of bats and swallows and on shrimps. The male swamp eel excavates a mucus-lined burrow in which the eggs are laid, and the male guards the nest.

Status

The chief threats faced by this swamp eel is from pollution from untreated sewage and waste water which may seep into the aquifer, and from human disturbance. The

has rated this eel as being an "

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

". This is on the basis that the area occupied by this species is limited in extent, and the number of individuals is thought to have declined drastically over the last ten years, and is likely to continue doing so, due to a decrease in the quantity and quality of suitable habitat.

References

{{DEFAULTSORT:Blind Swamp Eel Cave fish Ophisternon Endemic fish of Mexico Taxa named by Carl Leavitt Hubbs Fish described in 1938 Taxonomy articles created by Polbot