Lamontichthys

Paixão, Andrea de Carvalho & Toledo-Piza, Mônica, 2009, Systematics of Lamontichthys Miranda-Ribeiro (Siluriformes: Loricariidae), with the description of two new species, Neotropical Ichthyology 7 (4), pp. 519-568 : 522-524

Lamontichthys P.de Miranda Ribeiro

Lamontichthys P.de Miranda Ribeiro, 1939: 12 [type-species: Harttia filamentosa LaMonte, 1935 , by original designation and monotypy].

Diagnosis. Species of Lamontichthys can be distinguished from all other loricariids by the presence of seven branched rays in the pectoral-fin (vs. six). Harttia leiopleura Oyakawa and Rineloricaria daraha Rapp Py-Daniel & Fichberg also possess seven branched pectoral-fin rays. Species of Lamontichthys can be distinguished from Harttia leiopleura by the presence of dermal plates on the upper lip and lateroventral plates on the thoracic region (vs. absent; Oyakawa, 1993) and from Rineloricaria daraha by having button-like papillae on the ventral surface on the lower lip (vs. long digitiform papillae), the lack of a postorbital notch and by having 14 caudal-fin rays (vs. 12; Rapp Py Daniel & Fichberg, 2008).

Five other characters observed only in skeletal preparations and detailed under “Character analysis and description” further distinguish Lamontichthys from other loricariids: 1) the trapezoidal shape of the lower pharyngeal plate, with the medial and lateral borders almost parallel, the medial border larger than the posterior border and at least twice as large as the lateral border (character 13); 2) the triangular and relatively elongate posterior expansion of the first epibranchial (character 14); 3) the large coronoid process in the dentary (character 23); 4) the contact (or proximity) between the proximal portions of the first three anal-fin pterygiophores (character 69); 5) the presence of two broad apophysis on the second preural centrum (character 77).

Common names. The common names used for Lamontichthys usually refer to more than one species of the genus or even to other Loricariinae . Brazil: “bode-cachoeira”, “bode-cachimbo” and “bode-casco-de-anta” ( Silvano et al., 2001; Cunha & Almeida, 2002); Colombia: “bomba” ( Galvis et al., 1997); Ecuador: “raspabalsa” (Ferraris Jr., 2003: 336); Finland: “siimaeva” ( Varjo et al., 2004); Germany: “filament-störwels” (Baensch & Riehl, 1997); Peru: “shitari” (Ortega & Vari, 1986); Venezuela: “tabla” or “paleta” (F. Provenzano, pers. comm.), and “paleta gibosa” (Taphorn & Lilyestrom, 1984b).

Geographic distribution. SouthAmerican drainages including the upper and central portions of rio Solimões-Amazonas, the drainages of río Ucayali, río Marañon and río Napo, the upper regions of rio Purus and rio Juruá , rio Madeira and rio Tocantins basins. It also occurs in the middle and upper río Orinoco basin, and in the lago Maracaibo drainage ( Fig. 2). Key to the species of Lamontichthys

1. Teeth with short cusps ( Fig. 3b); anterior tip of snout covered with plates or with an inconspicuous area lacking plates; dentary 11.5-19.1% HL in specimens larger than 100 mm SL .............................................................................. 2

1’. Teeth with long cusps ( Fig. 3a); anterior tip of snout not covered with plates ( Fig. 4); dentary 18.4-23.4% HL in specimens larger than 100 mm SL ....................................... 4

2. 19-21 lateral plates in the mid-ventral series; a single large triangular plate extending from base of last pelvic-fin ray to anterior margin of anus ( Fig. 5); 5-6 lateroventral thoracic plates in specimens larger than 100 mm SL; dorsal-fin spine not prolonged into a long filament. (lago Maracaibo drainage) ........................................................ L. maracaibero

2’. 15-18 lateral plates in the mid-ventral series; more than one plate from base of last pelvic-fin ray to anterior margin of anus ( Fig. 1); 6-10 lateroventral thoracic plates in specimens larger than 100 mm SL ( Fig. 1); dorsal-fin spine prolonged into a long filament ............................................ 3

5. First branched dorsal-fin ray 26.1-36.8% SL and pectoralfin spine 22.9-30.5% SL in specimens larger than 50 mm SL; dark pigments scattered along dorsal-fin spine. (tributaries of upper rioAmazonas) ....................................... L. stibaros

5’. First branched dorsal-fin ray 21.9-26.0% SL and pectoralfin spine 19.7-22.4% SL in specimens larger than 50 mm SL; dark pigments arranged in transversal bands along dorsalfin spine. (upper rio Tocantins basin) ........ L. avacanoeiro

3. Pectoral-fin spine prolonged into a long filament in specimens larger than 60 mm SL; head width 97.4-111.1% HL; interorbital distance equal to distance from orbit to exposed margin of cleithrum (rarely shorter) ( Fig. 6). (upper and middle rio Amazonas basin) ............................................. L. filamentosus

3’. Pectoral-fin spine not prolonged into a long filament; head width 82.6-96.9% HL; interorbital distance larger than (rarely equal to) distance from orbit to exposed margin of cleithrum ( Fig. 6). (rio Orinoco basin) .................... L. llanero

4. Distal tip of last dorsal-fin ray extending short of vertical through anal-fin origin; orbital diameter 16.6-17.3% HL in specimens larger than 70 mm SL; two small plates on the ventral mid-line of the caudal peduncle ( Fig. 7). (rio Tocantins basin) ................................................ L. parakana

4’. Distal tip of last dorsal-fin ray at the vertical through analfin origin; orbital diameter 13.6-16.8% HL in specimens larger than 70 mm SL; three small plates on the ventral midline of the caudal peduncle ( Fig. 7) ..................................... 5