Six- and seven-banded morphs of Cyphotilapia frontosa have been shown to be members of the same species.
New specimens of the six-banded morph of Cyphotilapia frontosa collected from the northern half of Lake Tanganyika, and specimens of the seven-banded morph of C. frontosa collected from Kigoma, Tanzania, have allowed scientists to analyse differences between the two morphs.
Tetsumi Takahashi, Benjamin Ngatunga and Jos Snoeks, who reported their findings in the latest issue of Ichthyological Research, the journal of the Ichthyological Society of Japan, said that the two morphs were conspecific.
The authors said that both morphs could easily be told apart from Cyphotilapia gibberosa - the second Cyphotilapia species described in 2003.
"The six- and seven-banded morphs of C. frontosa could be easily distinguished from C. gibberosa because C. frontosa has fewer scales between the upper and lower lateral lines and a more elongated body", the authors wrote.
"The six-band morph is easily distinguished from the seven-banded morph by its colour pattern and geographical pattern."
OverlapAlthough the dorsal-fin base length and the number of dorsal spines was much greater in the six-band morph, the morphs were still considered to be a single species because there was an overlap between the two.
The number of anal-fin spines was invariable, so was not included in statistical analyses. The other 11 meristic characters examined, including scale and tooth counts, differed between morphs but also overlapped.
The study is a follow-up to the Takahashi and Nakaya paper of 2003 which split the Cyphotilapia genus in two, and described Cyphotilapia gibberosa from the southern end of the Lake.
A lack of specimens of the six- and seven-banded morphs in the original study meant that Takahashi and Nakaya were unable to discuss the taxonomic position of the morphs in the same paper.
The seven-banded Cyphotilapia frontosa examined were collected from Kigoma, Tanzania, at a depth of 24-25m, while the six-banded morph came from eight localities including Bujumbura, Luhanga, Pemba, Gitaza, Nyanza lac, Kolobo, Kabimba and Tembwe in the northern half of the Lake.
Cyphotilapia gibberosa occurs only in the southern portion of the Lake, with the specimens examined having been captured in Kasenga, Moliro, Cape Kaku, Mtondwe Island, Kilewa Bay and Myako.
You can view the distribution of C. frontosa and C. gibberosa on Fish Mapper.
For more information see the paper: Takahashi T, Ngatunga B and J Snoeks (2007) - Taxonomic status of the six-band morph of Cyphotilapia frontosa (Perciformes: Cichlidae) from Lake Tanganyika, Africa. Ichthyological Research, 2007, 54: 55-60.