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Territoriality and nutritional condition in Cynotilapia afra (Gunther) and Pseudotropheus zebra (Boulenger), cichlidae in Lake Malawi National Park, Malawi
Author(s) -
Munthali S. M.
Publication year - 1996
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.1996.tb00076.x
Subject(s) - territoriality , biology , courtship , national park , ecology
The standard length, diurnal activities, territory sizes, and areas over which individuals foraged and the nutritional condition of territorial and non‐territorial Cynotilapia afra and Pseudotropheus zebra were compared. Results show that territorial tenureship in these fishes does not depend on the male size, implying that aggressiveness, experience and motivation are more important in the maintenance of territory. However, terri‐toriality in C. afra (t = 10.93, P < 0.05) and P. zebra (t = 3.31, P < 0.05) manifests itself in the reduction of nutritional condition because territorial males engage in energetically more demanding activities, e.g. courtship displays, fertilizing ripe females and chasing intruders that trespass into their territories. Territorial C. afra (t = 4.77; P < 0.05) and P. zebra (t = 5.89; P < 0.05) also fed over significantly smaller areas and spent significantly less time feeding than did non‐territorial males. The biological significance of territoriality in these fish species is therefore not food intake, but mate attraction and reproductive success for which they trade off their nutritional condition. However, there might be a nutritional threshold below which the cost out‐weighs the benefit. Hence, territorial males in poorer health abandon their territories in order to regain their condition.