Apteronotus albifrons (Linnaeus, 1766)

Carlos David de Santana, 2003, Apteronotus caudimaculosus n. sp. (Gymnotiformes: Apteronotidae), a sexually dimorphic black ghost knifefish from the Pantanal, Western Brazil, with a note on the monophyly of the A. albifrons species complex., Zootaxa 252, pp. 1-11 : 6

[[ Apteronotus albifrons (Linnaeus, 1766) ]]

Apteronotus albifrons species complex and its monophyly

Based on the description of A. caudimaculosus and previous studies (e.g., de Santana, 2002), it is hypothesized that the widespread populations of A. albifrons , represent a species complex. The pale bands on the tail, considered to be diagnostic character for a single species actually represent a synapomorphy for this monophyletic clade. This premise is reinforced by the presence in this group of some undescribed species, as illustrated in Planquette et al. (1996: 405, 407). A uniquely derived character among the Gymnotiformes, the presence of two clear bands encircling the caudal peduncle throughout its development defines the A. albifrons species complex . A similar feature is observed in individuals of A. cuchillo ; however, it is only present in specimens below 140.0 mm TL. Currently, I am studying other putative species complexes, in nominal populations of A. brasiliensis , A. leptorhynchus and A. rostratus (e.g., de Santana, 2002). A study concerning the phylogenetic relationships of Apteronotus (sensu stricto) and a new classification of the genus is in preparation.