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Freshwater Fish from Uruguay 2nd. edition (1)

Description: Dorsal soft rays (total): 10-14; Anal soft rays: 6 - 7; Vertebrae: 35 - 36. This species is distinguished from all its congeners, except S. operculatum by the following characters: maxillary barbel is smaller than half-length of the head (vs. larger than half-length of the head); tips of pectoral-fin rays extending beyond the interadial membrane (vs. not extending beyond interadial membrane); skin flap in the posterior margin of the opercle pointed and long (vs. round an short); fleshy flap at the base of the maxillary barbel located anteriorly, it is thick, prolonged up to the snout and with distal margin straight (vs. fleshy flap located posteriorly, thin, restricted to the maxilla and with distal margin rounded); caudal fin with a transversal black bar distally (vs. no black bar) differs S. operculatum by having a midlateral line of 6-9 rounded black blotches larger than opercle (vs. midlateral line of 10-14 rounded black blotches as large as or smaller than opercle), tip of nasal barbel usually extending beyond anterior margin of eye (vs. never reaching anterior margin of eye), tip of maxillary barbel extending between anterior and posterior margins of interopercle (vs. tip never surpassing anterior margin of interopercle). Habitat: Inhabits rivers and streams usually with sandy bottoms. Collected syntopically with S. minutum in some localities. Individuals larger than 3.5 cm SL are reported to be capable of spawning and thus are considered adults. Widely distributed in rivers and streams that drain to laguna dos Patos (Brazil) and lagoa Mirim (Brazil and Uruguay); and in small Atlantic coastal drainages of Uruguay. Diet: Stomachs of eleven specimens were analysed where 6 had immature aquatic Diptera (Chironomidae), Oligochaeta, unidentified plant fragments and sand. A study showed that the diet of immature individuals was composed of Chironomidae and Ephemeroptera. Etymology: Named after the word ‘macanuda’, a regional adjective to describe a ’large and strong’ person, referring to the species being the largest of the genus.

None

None

Trichomycteridae

South America: Small Atlantic coastal drainages (southeastern Brazil), and lower Uruguay River basin (Uruguay and Argentina).

8.5cm (3¼ins)

-

6.0-7.0.

Ferrer, J. and L.R. Malabarba, 2020. Systematic revision of the Neotropical catfish genus Scleronema (Siluriformes: Trichomycteridae), with descriptions of six new species from Pampa grasslands. Neotrop. Ichthyol. 18(2):1-81.
Froese, R. and D. Pauly. Editors. 2023. FishBase. World Wide Web electronic publication. www.fishbase.org, ( 06/2023 ).
Loureiro M, González-Bergonzoni I, Teixeira de Mello F. 2023. Freshwater Fishes of Uruguay. Second edition. Vertebrate Zoology Laboratory, Faculty of Sciences, University of the Republic.