| Lepthoplosternum | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Siluriformes |
| Family: | Callichthyidae |
| Subfamily: | Callichthyinae |
| Genus: | Lepthoplosternum Reis, 1997 |
| Type species | |
| Callichthys pectoralis Boulenger, 1895 |
|
| Species | |
Lepthoplosternum is a small genus of freshwater catfish in the Callichthyinae subfamily of the armored catfish family, and consists of six species.[1]
Contents |
The type species for this genus is Callichthys pectoralis. The name is derived from the Greek leptos, meaning "thin", the Greek hoplon, meaning "weapon", and the Greek sternon, meaning "chest" or "sternum".[2] Lepthoplosternum is relatively basal among callichthyines, being sister to the clade comprising Megalechis + Dianema + Hoplosternum. Callichthys is the most basal genus in the subfamily.[3]
L. stellatum and L. ucamara are hypothesized to form a partially unresolved polytomy 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.[3]
Lepthoplosternum is widely distributed in cis-Andean South America south of the Orinoco River basin. L. pectorale is from the Paraguay River, L. altamazonicum is known only from the upper Amazon River basin in Peru and Brazil, L. beni is from the upper Madeira River basin in Bolivia and Peru, and L. tordilho is from the lower Jacui River drainage in southern Brazil.[3] L. stellatum is so far known from the type locality only, the Igarapé Repartimento, a tributary of the mouthbay lake, Tefé Lake, some 6 km south of the town of Tefé, Amazonas, Brazil.[3] L. ucamara is known from the Pacaya-Samiria National Reserve in the lower Ucayali River in Peru and from the area of confluence of the Solimões River and Japurá River in Brazil.[3]
Lepthoplosternum species usually inhabit lentic or slow flowing water bodies and are often associated with marginal or floating vegetation.[3] L. ucamara has even been found in hypoxic conditions.[3] However, the type locality of L. stellatum is a stream, permanently flowing and well oxygenated.[3]
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.[3]