Staff directory
Emmanuel Vreven
Biology
Vertebrates
Vertebrates
Publication details
Ibala Zamba, A., Mamonekene, V., Vreven, E. & Stiassny, M.L.J. 2016. ‘Rehabilitation of Xenocharax crassus (Teleostei: Distichodontidae), a species endemic to the Congo basin in central Africa’. Ichthyological Explorations of Freshwaters 27(4): 97-106. München, Germany : Verlag Dr. Friedrich Pfeil. ISSN: 0936-9902. (PR).
Article in a scientific Journal / Article in a Journal
Xenocharax crassus Pellegrin, 1900, originally described from the Alima River (Congo basin, Republic of Congo)
but synonymised with X. spilurus by Daget in 1960, is rehabilitated. Xenocharax crassus, a Congo basin endemic,
is distinguished from X. spilurus, the latter found exclusively in basins of the Lower Guinean ichthyofaunal
province, by the presence of a large black mark on the anterior part of the dorsal fin (versus absence), a small,
round, black spot at the base of the caudal peduncle (versus a large ovoid spot covering the peduncle base), and
a wider mouth (29-34 % HL vs. 24-29). For specimens of similar sizes, X. crassus has a shorter dorsal-adipose
distance than X. spilurus. Furthermore, most X. crassus specimens have 6 supraneurals (frequency: 83 %) versus
7 (frequency: 79 %) in X. spilurus. With molecular data the species is readily distinguished from X. spilurus by
10 apomorphic, non-synonymous nucleotide transitions in the three sampled genetic markers (nd2, cyt-b, and
myh6). A lectotype is designated for X. spilurus.