C65

biology_ecology

Ecological notes. The specimens examined herein were captured in a clear water stream, with sandy ground and fast flowing. After capture the specimens are light orange. This color remains in aquarium when the water conditions are adequate to its biological aspects. In the type locality of the new species no other congener were observed in syntopy (H. - G. Evers pers. comm.).

A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990

conservation

Conservation status. At the time of the capture of Corydoras eversi, the type locality presented high degree of deforestation and presence of nearby cattle farming. There was an encampment of the ʻMovimento dos Trabalhadores Rurais Sem Terra - (MST) ʼ just a few kilometers away from the collection site (Hans-Georg Evers pers. comm.). Despite the type locality presents, at least in the year of 1998, nearby human and cattle occupation and severe deforestation, in addition to the scarcity of the known material of C. eversi, apparently, no additional collecting trip has been performed in the region since 1998. Therefore, the current situation of the type locality is unknown and, with the available data, it is not possible to determine if any of the aforementioned potential threats has directly affected the new species. Additionally, it is very possible that the new species may be further spread than the type locality region, potentially occurring in other creeks and streams of the region. Thus, it seems like the most appropriate conservation status according to the International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee,

A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990

description

Description. Morphometric data presented in Table 1. Head compressed with convex dorsal profile; triangular in dorsal view. Snout short and rounded. Head profile convex from tip of snout to anterior nares; ascending nearly straight from this point to tip of posterior process of parieto-supraoccipital; region just posterior to eye slightly concave in some specimens. Profile slightly convex along dorsal-fin base. Postdorsal-fin body profile nearly straight to adipose-fin spine; concave from this point to caudal-fin base. Ventral profile of body slightly convex from isthmus to pelvic girdle. Profile nearly straight from pelvic girdle to base of first anal-fin ray; concave until caudal-fin base. Body roughly elliptical in cross section at pectoral girdle, gradually becoming more compressed toward caudal fin. Eye rounded, located dorso-laterally on head; orbit delimited dorsally by lateral ethmoid, frontal and sphenotic, ventrally by infraorbitals. Anterior and posterior nares close to each other, only separated by flap of skin. Anterior naris tubular. Posterior naris relatively distant to anterodorsal margin of orbit, separated from it by distance equal to twice of naris diameter. Mout

A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990

description

ur n: lsid: zooban k. org: act: 541 C 78 B 5 - 98 B 6 - 4 FBF- 89 A 3 - 6961 C 9 EA 74 D 2 Figs. 1, 2 a, c, 3 - 5

A new Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the rio Araguaia basin, Brazil, with comments about Corydoras araguaiaensis Sands, 1990