Référence originale dans:
- Tropheus sp. 'ikola', Konings et al., 1992, nom provisoire
- Tropheus sp. 'black', Konings, 2019:71, synonyme senior
Étymologie: The provisional name refers to the area in which this potentially undescribed species is found.
Nom commun: Kaiser Tropheus, Kaiser I (by opposition with the Kiriza black Tropheus, which is often named Kaiser II).
Diagnose: Same as Tropheus sp. 'black', except that the band on the flank is very broad but never reaching the top of the dorsal fin, has perfectly straight vertical edges and is pure lemon yellow with no traces of red.
Taille: As most members of the genus, Tropheus sp. 'ikola' reaches 12-14 cm in TL (Total Length).
Distribution: Only found on the central Tanzanian coast from north of the village of Ikola to south of the village of Isonga.
Biotope: As other Tropheus of the moorii type, Tropheus sp. 'ikola' inhabits the upper rocky zone free of sediments.
Conservation: Tropheus sp. 'ikola' n'est pas évalué par l'Union Internationale pour la Conservation de la Nature dans la Liste rouge des espèces menacées. Abundant and well-sized in imports, this restricted range very well individualized variety is nevertheless vulnerable to genomic pollution would another "black" Tropheus (for example, from Mabilibili) is introduced in its habitat.
Alimentation: Feeds from the rocks algal bio-cover (aufwuchs). The squarish mouth with straight parallel jaws is identical to those of other members of the genus, except for Tropheus duboisi.
Reproduction: As other members of the genus, Tropheus sp. 'ikola' is a maternal mouth-brooder which produces a rather low number of eggs (usually from 6-20). In compensation, the pear-shaped eggs are among the largest in the family (7 mm in their longest diameter), giving birth to rather large and well developed young. The incubation period is basically 3 weeks, but often continues during several more weeks (up to 10), during which the young are released from time to time by the mother in sheltered areas and may feed inside their mother's mouth. The male does not take any part in the parental care and usually chases the female away immediately after the spawn, but in aquarium, he may tolerate her in the immediate surroundings of his territory.
Maintenance: Tropheus sp. 'ikola' does not differ markedly from its congeners in maintenance requirements in aquarium. In aquarium, males of all Tropheus species tend to defend their own territory, while linear hierarchies are found only in case of overcrowded small tanks. In order to observe their natural behavior in aquarium, Tropheus must be kept in small groups of several males and females in a large tank (at least 500 liters, but preferably 1000 liters or more) together with other tropheines such as Petrochromis or Simochromis. In smaller tanks, their murdering tendencies usually lead to the eradication of all subordinate males and females, unless the tank is markedly overcrowded. In some cases, when the sexes fit well together, they may be kept as a single pair, a situation which may last several months or years, until the male may finally kill his mate by frustration.
The water of the aquarium must be powerfully filtered, hard and alkaline (ph 8.2), with a temperature range around 23-26°C. These fishes must be given mainly ballast-rich foods, as they are very sensitive to intestinal problems. As for all members of the genus, Tropheus sp. 'ikola' tend to peck the fins of its tank-mates, especially when young, thus reducing sometimes considerably their extensions to unsightly extends.
Commentaires: First considered a mere variety of Tropheus sp. 'black', Tropheus sp. 'ikola' is now usually considered a different species, following Konings (1998), since its diagnostic characteristics are remarkably stable. This is probably linked to its restricted range, isolated from other black Tropheus, which led this variety to an uniformity in its appearance and some degree of genetic drift. Nevertheless, as it fully shows all diagnostic characteristics of all "black" Tropheus, it is perhaps better to treat it as a well-individualized subspecies. Schupke (2003) treats it as a different lineage with a single population, but logically, he also gives the "Kirschfleck moorii" its own lineage with several populations. As both hybridize in natural habitat (since cargoes of Ikola Tropheus had been inopportunely released in the Bulu Point population) and as they share all the very peculiar features of other black Tropheus (namely permanently black tail, definitive loss of the juvenile barred pattern with age, yellow to orange-red patches on the body and red upper iris), they probably are best to be considered as a single polytypic species.
The "Kaiser II" black Tropheus from Kiriza is similar in appearance to the "Ikola", but is easily distinguishable by its narrower band reaching the top of the dorsal fin, and which is less straightly bordered and a warmer yellow. Also, in the Ikola Tropheus, the band is the broadest found in any member of the genus (except some aberrant -or hybrid- "Kirschflecks", in which the two color patches are fused), sometimes extending from behind the operculum to the beginning of the caudal peduncle.
- Konings, Ad. 2019. "Tanganyika cichlids in their natural habitat, 4th edition". Cichlid Press. pp. 1-432. ISBN: 978-932892-26-0 (crc09277) (résumé)
- Konings, Ad. 1998. "Tanganyika Cichlids In Their Natural Habitat". Cichlid Press (crc00734)
- Konings, Ad & H.W. Dieckhoff. 1992. "Tanganyika Secrets". Cichlid Press. pp. 1-207 (crc01388)
- Schupke, Peter. 2003. "African Cichlids II, Tanganyika I, Tropheus". Aqualog (crc01827)
Tawil, Patrick. (juin 06, 2010). "Tropheus sp. 'ikola'". Cichlid Room Companion. Consulté le décembre 03, 2020, de: https://cichlidae.com/species.php?id=1730&lang=fr. (crc10867)