Sorubim elongatus Littmann, Burr, Schmidt and Isern 2001

Michael W. Littmann, 2007, Systematic review of the neotropical shovelnose catfish genus Sorubim Cuvier (Siluriformes: Pimelodidae)., Zootaxa 1422, pp. 1-29 : 18-19

Sorubim elongatus Littmann, Burr, Schmidt and Isern 2001

Slender Shovelnose Catfish (English), paleta delgada (Spanish)

Fig. 11 (Holotype), Fig. 12

Holotype: SIUC 30303 (123 mm SL). Peru: Departamento Loreto, Maynas Province, Ullpa Caño, 50 m upstream of confluence with Moena Caño, Río Itaya drainage, Río Amazonas basin (approx. 3°46’20”S 73°14’17”W); 14 Aug 1997, M. W. Littmann & R. E. Weitzell, Jr.

Diagnosis: Species of Sorubim distinguished from all congeners by the following combination of characters: modally 8 branched pectoral-fin rays; 22 anal-fin rays; 19 gill rakers on first pharyngeal arch; small patches of vomerine teeth not joined (Littmann et al. 2001b, fig. 3b) in adults; elongated head and body cylindrical in cross-section; depressed pelvic fins reaching approximately halfway from anus to anal fin origin; mental barbels inserted even with or posterior to gular apex (Littmann et al. 2001b, fig. 4b,); eye diameter of adults going 2.2-3.3 times into interorbital width.

Etymology: The name elongatus, an adjective, is Latin, meaning prolonged and refers to the extremely elongated shape of the head and body. Likewise, the first part of the English common name describes the general body shape of the fish (slender); the remainder of the name (shovelnose catfish) is familiar to enthusiasts of the aquarium hobby, and differs from that recommended for S. lima (i.e., Duckbill catfish) by Robins et al. (1991).

Distribution: Most records of Sorubim elongatus are from the mainstems and lower reaches of the Amazon, Essequibo, and Orinoco River basins (Fig. 9). Sorubim elongatus is the only species of Sorubim known from the Essequibo River, as represented by twelve specimens in the material examined.

One disjunct record in the Río Mamore system of Bolivia is based on four specimens captured by J. D. Haseman in 1909 and three specimens taken in the same system in 1982 by L. Lauzanne and G. Loubens, deposited at FMNH and MNHN, respectively.