Corydoras ortegai

biology_ecology

Habitat and ecological notes. Corydoras ortegai was mostly found inhabiting lotic habitats in the Río Yaguas basin, a whitewater tributary of Río Putumayo. The Río Yaguas has a muddy-brown color, with soft bottom of clay and sand where C. ortegai was relatively abundant. No individuals were captured in the small black or clearwater forest streams, nor lagoons that were also present in the area. The only congener found living syntopically with C. ortegai at the type locality was C. pastazensis. The region where C. ortegai was discovered has a high diversity of fishes (207 species recorded), and it is being proposed as a new protected area in Peru (Hidalgo & Olivera, 2004).

Corydoras ortegai, a new species of corydoradine catfish from the lower río Putumayo in Peru (Ostariophysi: Siluriformes: Callichthyidae)

description

Description. Morphometric data presented in Table 1. Head compressed, roughly triangular with rounded apex in dorsal view; dorsal profile slightly convex, nearly straight, rising moderately from nares to tip of parieto-supraoccipital process (Fig. 3). Snout profile rounded from upper lip to horizontal through anterior nares. Dorsal profile of body slightly convex from tip of parieto-supraoccipital process to last dorsalfin ray, then slightly concave to adipose-fin spine and descending straight downwards from this point to caudal-fin base. Ventral profile of body slightly convex from isthmus to anal-fin origin, mainly in pectoral- and pelvic-girdle region. Profile markedly straight, ascending obliquely from first analfin ray to caudal-fin base. Body roughly triangular in cross section at pectoral girdle, gradually becoming more compressed toward caudal fin. Eye round, located dorso-laterally on head; orbit delimited dorsally by frontal and sphenotic, ventrally by infraorbitals. Anterior and posterior nares proximal, only separated by flap of skin. Anterior naris tubular; its free tip with minute, roughly lanceolate, fleshy flap. Posterior naris close to anterodorsal margin of orbit,

Corydoras ortegai, a new species of corydoradine catfish from the lower río Putumayo in Peru (Ostariophysi: Siluriformes: Callichthyidae)

diagnosis

Diagnosis. Corydoras ortegai is distinguished from all other species of Corydoras, except C. panda, C. reynoldsi, C. weitzmani, and C. tukano, by having a transverse, dark bar (“ mask ”) across the orbit, and ground color of body uniform with large, dark rounded blotch midlaterally on trunk below adipose fin. The new species is distinguished from C. reynoldsi, C. weitzmani, and C. tukano by the absence of a midlateral trunk blotch at the dorsal-fin level, and the rounded shape of the trunk blotch at adipose-fin level. Corydoras ortegai differs from C. panda by its greater number of lateral body plates (24 dorsolateral / 21 - 22 ventrolateral vs. 22 - 23 / 20), dark brown dorsal-fin blotch absent (vs. present), several scattered chromatophores surrounding yellowish white area on midregion of cleithrum (vs. chromatophores absent or nearly absent on cleithrum), caudal fin with narrow series of dark brown blotches restricted to rays (vs. caudal fin hyaline), a slenderer body (depth of body 28.3 - 35.1 % SL vs. 40.0 % SL), and a narrower intercleithral area (maximum cleithral width 10.7 - 15.5 % SL vs. 18 % SL). Another feature helpful to distinguish the new species from its congeners i

Corydoras ortegai, a new species of corydoradine catfish from the lower río Putumayo in Peru (Ostariophysi: Siluriformes: Callichthyidae)

distribution

Distribution. Corydoras ortegai is only known from tributaries of the Río Yaguas, a tributary of the lower Río Putumayo, in Departamento Loreto, Peru, very close to the border with Colombia and Brazil (Fig. 4).

Corydoras ortegai, a new species of corydoradine catfish from the lower río Putumayo in Peru (Ostariophysi: Siluriformes: Callichthyidae)