Lamontichthys maracaibero Taphorn & Lilyestrom, 1984

Lamontichthys maracaibero Taphorn & Lilyestrom, 1984 View in CoL

Fig. 12 View Fig

Lamontichthys maracaibero Taphorn & Lilyestrom, 1984a: 94-95 View in CoL , 98, fig.1, table 1 [original description; type locality: “ Venezuela, Zulia, Distrito Miranda, río Motatán in el Puente Tres de Febrero”; paratypes from río Motatán and río Ariguisá]; Taphorn & Lilyestrom, 1984b: 17, 29 [key and common name; lago Maracaibo, Venezuela]; Galvis et al., 1997: 88 [description, habits, common names, illustrations, río Catatumbo system in Colombia and Venezuela]; Provenzano et al., 1998: 11-12, 21, 23 [type listed]; Eschmeyer, 1998: 1014 [listed]; Mojica, 1999: 562 [listed]; Isbrücker, 2001: 29 [listed]; Ferraris Jr., 2003: 336 [listed]; Ferraris Jr., 2007: 264 [listed].

Diagnosis. Lamontichthys maracaibero differs from all congeners in the presence of a single plate ( vs. two plates) between the pelvic-fin base and the anterior margin of the anus ( Figs. 1 View Fig and 5 View Fig ).

Specimens of L. maracaibero larger than 150 mm SL possess a deeper body at the predorsal region (14.0-15.1%, n = 6, vs. 11.5-13.5%, n = 26) relative to the other species of Lamontichthys (except for L. parakana for which specimens larger than 150 mm SL were not available for comparison), forming a hump between the head and the dorsal-fin origin. Lamontichthys maracaibero is further distinguished from L. filamentosus and L. llanero by the semi-oval shape of the lower lip ( vs. semicircular) ( Fig. 9 View Fig ); and from L. llanero by the reduced number of lateroventral thoracic plates in specimens smaller than 50 mm SL (5 to 6 plates, vs. 7 to 10), and from L. stibaros , L. avacanoeiro , and L. parakana by having the snout totally covered with plates at its anterior tip ( vs. presence of an area lacking plates) and by the teeth with short cusps ( vs. long) ( Fig. 3 View Fig ). The specimens of Lamontichthys maracaibero larger than 100 mm SL also differs from L. stibaros , L. avacanoeiro , and L. parakana in the relatively shorter head (16.7-17.8%, vs. 19.8-23.0% SL) and shorter dentary (14.8-19.1%, vs. 18.4-23.4% HL). Morphometric and meristic data are presented in Table 2 View Table 2 .

Geographic distribution. Lago Maracaibo basin ( Fig. 2 View Fig ).

Material examined ( 9 specimens; 63.4-210.2 mm SL): Colombia: ICNMHN 2166 , 5, 149.1-210.2, Catatumbo, Santander, río Catatumbo , córrego La Gabarra . Venezuela: Trujillo: lago Maracaibo drainage : MCNG 3592 View Materials , 1, 154.9, holotype; MCNG 3593 , 1 (of 4), 63.4, 1 cs *, 83.8, paratypes, Betijoque, río Motatãn , bridge “Tres de Febrero”. Zulia: INHS 35473 , 1, 131.3, río Santa Rosa .