A new species of Pimelodella (Siluriformes: Heptapteridae) from the Guiana Shield, Brazil

Abstract

A new species of Pimelodella is described from the Rio Ipitinga, Rio Jari basin, a left bank tributary of the Rio Amazonas in Brazil. The new species is diagnosed from all congeners by having a dark oval mark on the humeral region. It also differs from all congeners by a unique set of characters, including the presence of 47 to 49 total vertebrae, unpigmented areas dorsally and ventrally adjacent to the dark midlateral stripe, and maxillary barbels reaching at least to vertical through caudal fin insertion. Faunal similarities between the southern part of the eastern Guiana Shield and coastal drainages in the Guianas and Suriname are discussed.

Description of a new Pimelodella (Siluriformes: Heptapteridae) species with a discussion on the upper pectoral girdle homology of Siluriformes

“…A century has passed since the last taxonomic revision of Pimelodella (Eigenmann, ). Despite subsequent efforts (Bockmann & Slobodian, ; Leiva, ; Mees, ; Souza‐Shibatta et al ., ; Slobodian et al ., ; G. M. Guazzelli, unpublished data), the species boundaries within this genus remain unclear. Most species assigned to the genus have never been subject to rigorous taxonomic study and those currently considered as valid are a testament only to the list of available names.…”

“…Measurements are point‐to‐point distances taken with digital calipers under a dissecting microscope, following Slobodian et al . (). For clarification, some of the measurements are as follow: head length (from tip of snout to distal point of supraoccipital process); head depth (measured at anterior limit of supraoccipital process); eye diameter (longitudinal diameter of eye sphere); mouth gape (including lips, measured at external margin); barbel lengths (with barbel straightened along lateral or ventral surface of body); predorsal length (from tip of snout to anterior tip of spinelet); peduncle length posterior to adipose (measured from adipose‐fin base terminus to caudal‐fin insertion); peduncle depth (measured just posterior to adipose‐fin base terminus); peduncle length posterior to anal‐fin terminus (measured from anal‐fin terminus to caudal‐fin insertion).…”

Rapid assessment of the ichthyofauna of the southern Guiana Shield tributaries of the Amazonas River in Pará, Brazil

“…This pattern is further supported by the occurrence of the loricariid Parotocinclus halbothi and the heptapterid Pimelodella geryi Hoedeman 1961, which are known from both the NPDS and the Marowijne River in Suriname (Lehmann et al 2014;Slobodian et al 2017;Dagosta and de Pinna 2019). On the other hand, Cteniloricaria napova, Cyphocharax aninha, Hypomasticus lineomaculatus and Pimelodella humeralis (Covain et al 2012;Birindelli et al 2013;Wosiacki and Miranda 2013;Slobodian et al 2017) appear to be endemic to the Northern Pará Drainage System.…”

Taxonomic revision of Pimelodella Eigenmann & Eigenmann, 1888 (Siluriformes: Heptapteridae): an integrative proposal to delimit species using a multidisciplinary strategy

“…Many species of Pimelodella lack rigorous taxonomic study and, to some degree, those considered valid merely correspond to a list of unchallenged available names (Slobodian et al, 2017). Identification of Pimelodella species is expectedly troublesome, a fact blatantly demonstrated in collection material: the majority of material representing Pimelodella is undetermined, or wrongly identified at species level.…”

“…Pimelodella is distributed throughout cisand trans-Andean Neotropical drainages from Panamá to Argentina (Eschmeyer, Fricke & van der Laan, 2017). The majority of species in the genus have never been subject to rigorous taxonomic study and those considered as valid often merely correspond to a selected list of available names (Slobodian et al, 2017).…”