Cichlidae

Neumann, Dirk, Obermaier, Henriette & Moritz, Timo, 2016, Annotated checklist for fishes of the Main Nile Basin in the Sudan and Egypt based on recent specimen records (2006 - 2015), Cybium 40 (4), pp. 287-317 : 298

Cichlidae

The taxonomy of cichlids in the Nile is convoluted and needs thorough revision. The Delta, El Fayum and White Nile (Kosti) populations of Coptodon zillii (Gervais, 1848) seem to differ from each other in morphology, colouration and body shape. However, until revised, we assign all Coptodon specimens to C. zillii . The identity of Coptodon ismailiaensis (Mekkawy, 1995) and Oreochromis ismailiaensis Mekkawy, 1995 remains questionable. It was not possible to confirm the presence of both species at their type locality. The specimens in the type series of Coptodon ismailiaensis seem to be comparatively slender. Except for the lack of light spots on the caudal fin, holotype and paratypes of Coptodon ismailiaensis largely agree with C. zillii . It is currently unclear if C. ismailiaensis is a distinct species, or if it is based on aberrant specimens used in aquaculture or hybrids of escaped aquaculture specimens with C. zillii from the Delta. The situation for Oreochromis ismailiaensis is similar: holotype and paratypes largely agree with medium sized O. niloticus (Linnaeus, 1758) lacking the strikingly striped caudal fin. Similar Oreochromis have been observed at Qantir, 20 km SE from Ismailiyah, but additional material is necessary to allow a thorough comparison. If more specimens are available, the status of C. ismailiensis and O. ismailiensis should be carefully evaluated.

A similar variability is observed in Sarotherodon galilaeus (Linnaeus, 1758) among populations from Lake Mariut, Kosti on the White Nile and Sennar on the Blue Nile. If the observed variation attributes to escaped aquaculture specimens or hybrids, interbreeding with autochthonous populations or to natural variation of autochthonous populations needs further investigation. Unless clarified, all record- ed specimens are assigned to S. galilaeus . Inside Egypt, the status and range of introduced O. mossambicus (Peters, 1852) and O. spilurus (Günther, 1894) – if established – is currently unclear ( FAO, 2010); neither of both has been observed in the Sudan so far.

Because of the unresolved taxonomy of the Hemichromis fasciatus Peters, 1857 group and the unclear type locality of Hemichromis fasciatus in West Africa, we refer to the Nile population as Hemichromis cf. fasciatus . The Nile Delta might harbour two deviant H. letourneuxi populations: one slender elongated and rather yellowish form in the isolated Lake Birkat-Abu-Jumas which is in direct vicinity of Lake Timsah in Ismailia, and one more deep bodied stout form collected in irrigation canals in Ismailia. Both seems to differ from fishes collected at the type locality Lake Mariut, but more material is needed to clarify their status. The observed variability between the two populations in the eastern delta could be linked to salinity levels in Ismailia; both locations are very close to the brackish Lake Timsah, but Birkat-Abu Jumas has no direct connection and seems isolated. We refer to both Ismailia populations as H. cf. letourneuxi in annexe 3 and mention them separately in annexe 2. Inside Lake Mariut, two Haplochromis seem to occur in sympatry, they apparently differ in several morphological characters, e.g. squamation on the chest and pectoral fin base, as well as in several scale counts and breeding behaviour. They seem close to H. wingatii specimens from the Semliki and Lake Albert, but the western and eastern Delta likely harbour at least two distinct populations which are preliminary identified here as Haplochromis sp. “Delta1” and Haplochromis sp. “Delta2” (Schraml, pers. comm., 2016). Further, we refer to the abberant Haplochromis observed by Schraml (pers. comm., 2016) in the El Fayum lakes here Haplochromis sp. “Fayum”, as they apparently differ from the Haplochromis in the Nile River. Because of the complexity of Haplochromis in general and unresolved taxonomy inside the Nile Basin in particular, we refrain from drawing any premature conclusions, but suppose Lower Nile Haplochromis are not conspecific with H. wingatii or H. loati .