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Congo River basin catfishes previously identified as Doumea alula (Amphiliidae, Doumeinae) were found to include three species that belong not to the genus Doumea but are, instead, the sister-group to a clade formed by all remaining Doumeinae. The species are assigned to a new genus, Congoglanis. Characters delimiting the Doumeinae and the clade consisting of all members of the subfamily except Congoglanis are detailed. Congoglanis alula is distributed throughout much of the Congo River basin; C. inga, new species, is known only from the lower Congo River in the vicinity of inga Rapids; and C. sagitta, new species, occurs in the Lualaba River basin of Zambia in the southeastern portion of the Congo River system.
CATFISHES of the subfamily Doumeinae of the Amphiliidae inhabit rapidly flowing rivers and streams across a broad expanse of tropical Africa. Recent studies of the Doumeinae documented that the species diversity and morphological variability within the subfamily are greater than previously suspected (Ferraris et al., 2010). As part of a continuing study of the Doumeinae, we examined extensive series of specimens from throughout the Congo River basin that conformed to the previous concept of Doumea alula (Fig. 1). Our examination revealed that the specimens actually represented more than one species and that all of those species lacked some of the characters considered diagnostic of the Doumeinae. The objective of this report is to reevaluate the limits and defining features of Doumea and the Doumeinae, name a new genus to accommodate Doumea alula and its related species, redefine and redescribe D. alula, describe and name the two newly discovered species, and provide a summary of the distribution of species of the new genus within the Congo River basin.
MATERIALS AND METHODS
Counts and measurements follow the methods outlined by Skelton (1981, 2007), with fin-ray counts taken from whole specimens. Vertebral counts were taken from radiographs and include the five Weberian-complex centra that precede the first rib-bearing vertebra, and a single complex ural centrum. A summary of measured characters is presented in Table 1. Abbreviations in the text are standard length (SL), head length (HL), and cleared-and-counterstained specimen (CS). An asterisk following a meristic value in the description indicates that of the holotype. Institutional codes are as listed at http://www.asih.org/node/204.
Congoglanls,...