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Leptodoras

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Osteichthyes
Classis: Actinopterygii
Subclassis: Neopterygii
Infraclassis: Teleostei
Superordo: Ostariophysi
Ordo: Siluriformes
Familia: Doradidae
Genus: Leptodoras

Leptodoras is a genus of catfishes (order Siluriformes) of the family Doradidae.

Taxonomy

Leptodoras is a monophyletic genus based on the single unique characteristic: presence of an infranuchal scute. This scute is the first in a series of well-developed midlateral scutes characteristic of most doradids.[2] It is one of the most derived genera within the clade of fimbriate-barbel doradids.[2] The most closely-related genus to Leptodoras is Anduzedoras.[2]

This genus includes eleven species, making it the largest doradid genus.[2] There has been taxonomic confusion due to similarities of some species with each other and members of other genera. Misunderstood distributions and identities of some species added to this confusion. Most species were described from small geographic areas without information on their potential distributions. Also, specimens have been rare in museums until recently.[3] An assessment in 2005 diagnosed Leptodoras and its seven species while describing three new species.[3]

Distribution

Leptodoras species are distributed in large, predominantly lowland rivers throughout the northern half of cis-Andean South America.[3] Species are distributed throughout lowlands in the Orinoco, Amazon, and Tocantins basins and several coastal river systems that enter the Atlantic between the mouths of the Orinoco and Amazon. Leptodoras is not known from trans-Andean drainages or Atlantic-slope drainages south of the Tocantins.[3]

Physical description

Leptodoras is easily recognized by its long conical snout and well-developed oral hood formed by the membranous union of maxillary barbels, paired jaw barbels on the chin, and lip structures.[3] It has fimbriate barbels.

Ecology

Most species of Leptodoras are truly benthic and typically inhabit the deep swift-flowing waters of large rivers. Many species of Leptodoras migrate at dusk into shallow waters near shore to forage over beaches and shoals of sand or silt. Other species, such as L. juruensis and L. myersi, appear more restricted to deep channel habitats. Leptodoras species are not known from elevations exceeding 500 metres (1600 ft) above sea level and most records are from below 200 m (660 ft).[3]

The oral hood found in Leptodoras species presumably facilitates the detection and suction-feeding of shallowly buried invertebrates. Stomach contents typically include chironomid larvae, sand, and detritus.[3]

References

1. ^ Birindelli, José L. O.; Sousa, Leandro M. (2010). "New Species of the Thorny Catfish Genus Leptodoras (Siluriformes: Doradidae) from Rio Fresco, Xingu Basin, Brazil". Copeia 2010 (2): 292–299. doi:10.1643/CI-09-153.
2. ^ a b c d e Birindelli, José L. O.; Sousa, Leandro M.; Sabaj Pérez, Mark H. (2008). "New species of thorny catfish, genus Leptodoras Boulenger (Siluriformes: Doradidae), from Tapajós and Xingu basins, Brazil". Neotropical Ichthyology 6 (3): 465–480.
3. ^ a b c d e f g Sabaj, Mark Henry (2005). "Taxonomic assessment of Leptodoras (Siluriformes: Doradidae) with descriptions of three new species" (PDF). Neotropical Ichthyology 3 (4): 637–678. doi:10.1590/S1679-62252005000400020. http://silurus.acnatsci.org/ACSI/participants/profiles/Sabaj/pdfs/Sabaj2005_Leptodoras.pdf.

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Source: Wikispecies: All text is available under the terms of the GNU Free Documentation License