Lamontichthys maracaibero Taphorn & Lilyestrom, 1984

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 : 530-531

Lamontichthys maracaibero Taphorn & Lilyestrom, 1984 Fig. 12

Lamontichthys maracaibero Taphorn & Lilyestrom, 1984a: 94-95 , 98, fig.1, table 1 [original description; type locality: “ Venezuela, Zulia, Distrito Miranda, río Motatán in el

Table 2. Morphometric and meristic data for Lamontichthys llanero and L. maracaibero . SD = standard deviation. L. llanero L. maracaibero

Variable

N Range Mean SD N Range Mean SD

Standard length (mm) 37 32.4-162.5 104.1 9 63.4-210.2 150.0

Percents of standard length

Head length 37 17.4-23.2 19.0 1.4 9 16.7-21.4 18.0 1.6 Predorsal length 37 26.5-31.9 28.1 1.2 9 25.5-29.6 27.5 1.3

Postanal length 37 47.0-57.1 54.9 2.0 9 53.5-57.1 55.2 1.2 Abdominal lenght 36 13.7-15.8 14.6 0.5 9 13.7-16.3 15.0 0.9

Thoracic length 37 13.6-16.5 14.8 0.8 9 13.2-15.6 14.0 0.8 Dorsal-fin length 26 25.3-40.5 34.0 3.0 9 25.7-31.4 29.7 1.9 Pectoral-fin length 37 20.2-25.4 22.2 1.3 9 20.0-21.7 21.0 0.6 Pelvic-fin length 37 17.7-22.8 20.2 1.1 9 18.2-19.9 19.1 0.5

Anal-fin length 35 17.9-25.2 21.8 1.6 9 19.6-22.0 21.1 0.8

Body depth at dorsal-fin origin 37 9.6-13.6 11.5 1.0 9 11.4-15.1 13.6 1.5

Caudal peduncle depth 37 1.3-1.8 1.5 0.1 8 1.5-1.7 1.6 0.1

Body width at dorsal-fin origin 37 11.4-15.5 14.3 0.8 9 14.4-16.9 15.8 0.9

Body width at anal-fin origin 37 8.5-12.9 11.5 0.9 9 11.5-14.5 13.2 1.1

Body width at caudal-fin origin 37 2.3-3.1 2.8 0.2 9 2.3-2.8 2.5 0.2

Percents of head length

Head width 37 82.6-96.9 92.4 3.1 9 90-112.7 103.4 7.2 Interorbital distance 37 29.4-35.0 31.9 1.4 9 29.7-33.4 31.2 1.3

Orbital diameter 37 15.0-19.4 17.5 1.1 9 12.8-16.4 14.9 1.2

Snout length 37 54.8-61.8 59.3 1.4 9 57.7-64.2 61.5 2.0

Dentary length 37 11.7-15.6 13.6 0.8 9 13.0-19.1 16.9 1.8

Lower lip width 37 9.0-16.6 12.5 1.7 9 11.1-14.0 12.4 1.0

Meristic data

Lateral plates of median series 36 32-33 32.7 0.5 9 32-34 33.0 0.5

Lateral plates of mid-ventral series 36 15-17 15.9 0.6 9 18-20 18.9 0.8 Ventrolateral thoracic plates 36 5-10 8.2 1.1 9 5-6 5.3 0.5 Premaxillary teeth 34 33-75 58.2 9.8 9 58-100 84.8 15.5

Dentary teeth 32 27-60 47.3 7.4 9 57-91 75.3 11.4 Dorsal-fin rays 37 II,7 II,7 0.0 9 II,7-8 II,7 0.3 Pectoral-fin rays 37 I,7 I,7 0.0 9 I,7 I,7 0.0 Pelvic-fin rays 37 i,5 i,5 0.0 9 i,5 i,5 0.0

Anal-fin rays 37 i,5 i,5 0.0 9 i,5 i,5 0.0 Caudal-fin rays 36 i,12,i i,12,i 0.0 9 i,12,i i,12,i 0.0

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 and 5).

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); 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). 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.

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

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 , 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 .