Neolamprologus furcifer (Boulenger, 1898)
11-Apr.-2014 — New description of Neolamprologus
Von Ad Konings
Even after many dives around the islands near Kipili, Tanzania, I hadn’t realized that in fact there appears to be two different furcifer-like cichlids present. The recent publication by Kullander et al. (2014) describes a new species that at first sight resembles N. furcifer, and is virtually indistinguishable from that species found all around the lake, but shares the same habitat with N. furcifer at (at least) Ulwile Island. Probably through character displacement the local N. furcifer population at the islands is characterized by a tail fin that has rounded lobes while that of the new species, N. timidus, is forked with long extensions. The tail of N. furcifer at all other areas in the lake is forked (hence its name, which means fork-bearer) and that was the reason divers never realized, when they saw N. timidus at the islands that this was a different species. The observations of the Karlsson brothers (they are co-authors on the paper) clearly state that they found pairs of N. timidus sometimes share the same rocky overhang with those of N. furcifer at Ulwile. This makes it unquestionably certain that N. timidus is a true species regardless of what origin it may have. The description gives a few characters in which they differ from N. furcifer and for me the simplest appears the shape of the pelvic fin. In N. timidus the first soft ray of the pelvic is the longest while in N. furcifer it is the second (or third) ray which gives the fin a more rounded appeal. The pelvic fin of N. timidus appears as a sharp-pointed triangle. There are other differences as you can read in the profile but the shape of the pelvic fin I found the most consistent when evaluating my photos. The paper also uses mitochondrial DNA probes to establish the notion that N. timidus and N. furcifer are not related genetically, but I hope that in the future taxonomists refrain from using this already outdated method of mtDNA phylogenies as they shed no new light on the specific status of an organism and at best may give an indication of the age of the particular gene(s) under investigation.
Kullander, Sven & Michael Norén, Mikael Karlsson, Magnus Karlsson. 2014. "Description of Neolamprologus timidus, new species, and review of N. furcifer from Lake Tanganyika (Teleostei: Cichlidae)". Ichthyological Explorations of Freshwaters. 24(4):301 - 328 (crc06100) (Kurzfassung)