Corydoras knaacki

biology_ecology

Ecological notes. Corydoras knaacki was captured in a swampy area with brownish “ tea-colored ” stagnant and very clear water. Some congeners, like Corydoras aff. aeneus, Corydoras cf. elegans and Corydoras cf. stenocephalus, were observed in the type-locality of C. knaacki (Fig. 7). Additionally, some Characiformes were also observed in syntopy, like Aphyocharax sp., Hoplias aff. malabaricus (Bloch, 1794), Hyphessobrycon sp. and Pyrrhulina vittata, Regan, 1912. Juveniles of Corydoras knaacki, between 8 up to 15 mm SL, are abundant in the shallow swampy area, forming bigger shoals. Specimens of Corydoras aff. aeneus with similar size to the specimens of C. knaacki were observed mixing in the same shoal with the new species, which is more abundant. Adult specimens of C. knaacki, up to 38 mm SL, can be found in small groups only in the deeper parts of the creeks, generally shaded by trees and palms. The adults do not form mixed shoals with Corydoras aff. aeneus.

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru

conservation

Conservation status. Despite the new species seems to be relatively well distributed in the río Madre de Dios basin, part of its currently known region of occurrence, the río Inambari basin, was recently affected by gold mining and road building. Lujan et al. (2013) demonstrated that the aforementioned threats have already affected the stream community structure of some tributaries to the río Inambari as a whole. However, since there is no available data of the possible direct effects of the gold mining and / or road building in the populations of C. knaacki, and also due to the quite plausible possibility that the new species may occurs in other non-affected water bodies of the region, the most reasonable category for Corydoras knaacki for the time being, according to the International Union for Conservation of Nature (IUCN) categories and criteria (IUCN Standards and Petitions Subcommittee, 2014), is Least Concern (LC).

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru

description

Description. Morphometric data presented in Table 1. Head compressed with convex dorsal profile; triangular in dorsal view. Snout short and markedly rounded. Head profile convex from tip of snout to anterior nares; ascending, smoothly convex from this point to tip of posterior process of parieto-supraoccipital; region of posterior process of parieto-supraoccipital nearly straight; slightly convex in some specimens. Profile slightly convex along dorsal-fin base. Postdorsal-fin body profile nearly straight to adiposefin spine; markedly 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; abruptly concave to 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 close to anterodorsal margin of orbit, separated from i

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru

description

urn: lsid: zoobank. org: act: F 1084581 - 5 CC 0 - 4 CED-AD 58 - 652 BB 7616 F 0 E (Figs. 1 - 5, Table 1)

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru