''Lepthoplosternum'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of freshwater

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 Callichthyinae subfamily of the armored catfish family.

Taxonomy

The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

for this genus is ''Callichthys pectoralis''. The name is derived from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''leptos'', meaning "thin", the Greek ''hoplon'', meaning "weapon", and the Greek ''sternon'', meaning "chest" or "sternum". ''Lepthoplosternum'' is relatively basal among callichthyines, being sister to the clade comprising ''

Megalechis ''Megalechis'' is a small genus of freshwater catfish in the Callichthyinae subfamily of the armored catfish family. Taxonomy The name is derived from the Greek ''megas'', meaning "great", and the Greek ''lekis'', meaning "plate". No uniquel ...

'' + '' Dianema'' + ''

Hoplosternum ''Hoplosternum'' is a small genus of freshwater catfish in the Callichthyinae subfamily of the armored catfish family. A fossil catfish has been identified as ''Hoplosternum sp.'' from the middle Miocene in the La Venta formation, Magdalena ...

''. ''

Callichthys ''Callichthys'' is a small genus of freshwater catfish in the Callichthyinae subfamily of the armored catfish family, and consists of 4 species from South America. The genus ''Callichthys'' is distributed in most freshwater drainages of South Am ...

'' is the most basal genus in the subfamily. ''L. stellatum'' and ''L. ucamara'' are hypothesized to form a partially unresolved

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tr ...

with ''L. pectorale'' and ''L. beni'', which are sister-species to each other. ''L. tordilho'' is sister to these four species and ''L. altamazonicum'' is the most basal species.

Species

There are currently six recognized species in this genus: * '' Lepthoplosternum altamazonicum'' R. E. dos Reis, 1997 * '' Lepthoplosternum beni'' R. E. dos Reis, 1997 * '' Lepthoplosternum pectorale'' ( Boulenger, 1895) * '' Lepthoplosternum stellatum'' R. E. dos Reis & Kaefer, 2005 * '' Lepthoplosternum tordilho'' R. E. dos Reis, 1997 * '' Lepthoplosternum ucamara'' R. E. dos Reis & Kaefer, 2005

Distribution and habitat

''Lepthoplosternum'' is widely distributed in

cis Cis or cis- may refer to: Places * Cis, Trentino, in Italy * In Poland: ** Cis, Świętokrzyskie Voivodeship, south-central ** Cis, Warmian-Masurian Voivodeship, north Math, science and biology * cis (mathematics) (cis(''θ'')), a trigonome ...

Andean The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S l ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

south of the

Orinoco River The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers , with 76.3 percent of it in Venezuela and the remainder in Colombia. It is the fourth largest river in the wor ...

basin.

Ecology

''Lepthoplosternum'' species usually inhabit

lentic A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems (''lentic'' re ...

or slow flowing water bodies and are often associated with marginal or floating vegetation. ''L. ucamara'' has even been found in

hypoxic Hypoxia means a lower than normal level of oxygen, and may refer to: Reduced or insufficient oxygen * Hypoxia (environmental), abnormally low oxygen content of the specific environment * Hypoxia (medical), abnormally low level of oxygen in the t ...

conditions. However, the type locality of ''L. stellatum'' is a stream, permanently flowing and well oxygenated.

Description

''Lepthoplosternum'' species are the smallest callichthyines (maximum standard length 60.3 mm) and are easily recognized by two synapomorphies: the lower lip with deep medial notch and a small, additional lateral notch forming fleshy projections on each side; and a single unbranched ray preceding the branched ones on the anal fin.

References

{{Taxonbar, from=Q6527930 Callichthyidae Fish of South America Catfish genera Taxa named by Roberto Esser dos Reis Freshwater fish genera