Brazilian ichthyologists Andrea Paixão and Mônica Toledo-Piza have described two new species of Lamontichthys plecs in a revision of the genus published in a recent issue of the journal Neotropical Ichthyology.
The revision recognises six valid species of the genus, of which Lamontichthys avacanoeiro and L. parakana are described as new.
The other four valid species are: L. filamentosus (upper and middle part of the Amazon River drainage); L. llanero (Orinoco River drainage); L. maracaibero (Lake Maracaibo drainage); and L. stibaros (upper part of the Amazon River drainage).
Lamontichthys avacanoeiro
This species, known from the upper part of the Tocantins River drainage, is distinguished from congeners in having a shorter first branched dorsal-fin ray (22.6–26.0% standard length) in fish larger than 70 mm standard length.
It further differs from congeners in having a combination of: an oval shaped area without plates on the front part of the snout, long-cusped teeth, semi-oval shaped lower lip, more than one plate between the base of the last pelvic-fin ray and the anterior margin of the anus, anal-fin origin at the vertical through the tip of the last dorsal-fin ray, abdominal length in fish larger than 150 mm standard length 17.6–17.7% standard length, unbranched anal-fin ray 16.9–20.3% standard length and eye diameter 13.6–16.2% head length in fish larger than 70 mm standard length.
This species is named after the Avá-canoeiros, native inhabitants from the upper Tocantins River drainage where this species occurs.
Lamontichthys parakana
This species, known from the lower part of the Tocantins River drainage, is distinguished from congeners in having the anal-fin origin at the vertical through the tip of the last dorsal-fin ray.
It further differs from congeners in having a combination of: the front part of the snout without plates, long-cusped teeth, semi-oval shaped lower lip, length of first branched dorsal-fin ray 26.4–31.0% standard length, lower jaw 20.1-22.6% head length in fish larger than 50 mm standard length, head width 101.3–106.1% head length, and eye diameter 16.6–17.3% head length in fish larger than 100 mm standard length.
This species is named after the Parakanã, native inhabitants from the lower Tocantins River drainage where this species occurs.
For more information, see the paper: Paixão, AC and M Toledo-Piza (2009) Systematics of Lamontichthys Miranda-Ribeiro (Siluriformes: Loricariidae), with the description of two new species. Neotropical Ichthyology 7, pp. 519–568.