|Diurnal variation of spacing and foraging behaviour in Tropheus moorii (Cichlidae) in Lake Tanganyika, eastern Africa|
Sturmbauer, C.; Dallinger, R. (1995). Diurnal variation of spacing and foraging behaviour in Tropheus moorii (Cichlidae) in Lake Tanganyika, eastern Africa. Neth. J. Zool. 45(1-3): 386-401
In: Netherlands Journal of Zoology. E.J. Brill: Leiden. ISSN 0028-2960, more
|Authors|| || Top |
- Sturmbauer, C.
- Dallinger, R.
Diurnal variation of behaviour was investigated in the epilithic algae feeder Tropheus moorii in lake Tanganyika. Territories, home ranges and four behavioural categories were recorded during the diurnal cycle. All four behavioural categories (foraging, locomotory activity, resting behaviour and total social interactions) followed a diurnal patter. Foraging activity was maximum between 12,30h and 16,30h and the observed diurnal pattern was similar to the rhythm found in a great number of marine algae feeders. In contrast to prvious observations individuals displayed both territorial and non-territorial activities during the day, expressed by specific colour-and behaviour patterns. The time spent in the own territories also varried with day time and was maximum between 12,30h and 16,30h. Non-territorial agregations of several induviduals outside territories were particularly observed during dawn and dusk.Territoriesmay primarily function as feeding territories since foraging was the most frequent behaviour. Non-territorial activities may allow induviduals to utilize additional food sources and the aggregation of several induviduals at dawn and dusk may indicate their behaviour at night. The observed diurnal rhythms of behaviour, together with the previously described complex social behaviour, and the alterated mating system of Tropheus, may have evolved as consequence of extreme sedentarity and close association to rocky substrate in order to optimize resource utilization.