''Stenolicmus ix'' is a species of

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Trichomycteridae- also called the Pencil or Parasitic Catfishes. It was described from the Curuá River, in the Brazilian state of

Pará Pará is a Federative units of Brazil, state of Brazil, located in northern Brazil and traversed by the lower Amazon River. It borders the Brazilian states of Amapá, Maranhão, Tocantins (state), Tocantins, Mato Grosso, Amazonas (Brazilian state) ...

, which is part of the Amazon River basin.

Taxonomy and naming

''S. ix'' is placed in the catfish family Trichomycteridae, the members of which are often referred to as Pencil catfishes and/or Parasitic catfishes. It is further places in the genus ''

Stenolicmus ''Stenolicmus'' is a genus of pencil catfishes native to South America. Species There are currently two recognized species in this genus: * '' Stenolicmus ix'' Wosiacki, Montag and Coutinho Coutinho is a Nobility, noble Portuguese language s ...

,'' which was erected in 1990 to accommodate ''S. ix's'' sister species '' Stenolicmus sarmientoi,'' which was described from

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

Etymologically Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the form of words an ...

, ''Stenolicmus ix'' is a blend of Greek and

Mayan Mayan most commonly refers to: * Maya peoples, various indigenous peoples of Mesoamerica and northern Central America * Maya civilization, pre-Columbian culture of Mesoamerica and northern Central America * Mayan languages, language family spoken ...

. The genus name comes from the Greek ''stenos (στενός)'' and ''(λικμός)'' which mean "narrow" and "sieve", respectively.Romero, P., 2002
An etymological dictionary of taxonomy
Madrid, unpublished. The species name ''ix'' is a Mayan word used to describe the

jaguar The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...

; ''S. ix'' was named in reference to the grouping of jaguar-like spots on the fish's dorsal surface.

Description

''S. ix'' is most physically similar to its sister species, ''S. sarmientoi.'' The head of this species is relatively small, and more dorso-ventrally compressed than the body, the overall dorsal surface of which is flat. Its branchial membranes are united to the isthmus, and its gill openings are unconstricted. The eyes, which sit dorso-laterally on the head, are small, with well-defined margins and distinct, integument-covered lenses. The posterior

naris A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

is round in shape, and similar in size to the eyes. The coloration of this species is mostly a uniform tan or cream that lightens somewhat ventrally. The spots, from which the species was named, are present on the dorsal surface and appear as dark brown, irregular blotches.

Distribution and habitat

Presently, ''S. ix'' is only known from its type locality, which is an unnamed tributary of the Rio Curuá in the lower

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

near Alenquer,

Pará State Pará is a state of Brazil, located in northern Brazil and traversed by the lower Amazon River. It borders the Brazilian states of Amapá, Maranhão, Tocantins, Mato Grosso, Amazonas and Roraima. To the northwest are the borders of Guyana and Sur ...

, Brazil. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

of this species was collected from a

lotic River ecosystems are flowing waters that drain the landscape, and include the Biotic component, biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its man ...

area in a small stream which was approximately 5m wide and less than 1m deep. The margins of the stream were dominated by amphibious vegetation and a large amount of

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that have fallen to the ground. This detritus or dead organic material and its constituent ...

was present on the bottom of the stream, though the fish itself is thought to dwell in the sand. ''S. ix'' was found to co-occur with 15 other species of fishes from orders such as the Characiformes, Perciformes, and other catfishes (Siluriformes).

References

{{Taxonbar, from=Q6407033 Fish of the Amazon basin Trichomycteridae Freshwater fish of Brazil Fish described in 2011