Rf. Oliveira et Vc. Almada, MATERNAL AGGRESSION DURING THE MOUTHBROODING CYCLE IN THE CICHLID FISH, OREOCHROMIS-MOSSAMBICUS, Aggressive behavior, 24(3), 1998, pp. 187-196
Maternal aggression was studied in Oreochromis mossambicus during the
mouthbrooding cycle. Brooding females were observed in heterosexual ca
ptive groups, and their agonistic interactions and behavioural activit
ies were registered. Brooding females were classified into three class
es according to the developmental stage of the brood they were incubat
ing: phase 1, brooding eggs; phase 2, brooding fry with yolk-sac; phas
e 3, brooding fry with exogeneous feeding. The behaviour of the broodi
ng females was compared with the behaviour of control non-incubating f
emales. During the brooding cycle females become increasingly more agg
ressive toward other individuals, with their aggressiveness reaching a
peak in phase 3. During the brooding cycle the females also suppress
their feeding activities. The outcome of the agonistic interactions (v
ictories-defeats) of the brooding females was positively correlated wi
th the brooding phase but not with clutch size. The main function of m
aternal aggression in O. mossambicus seems to be the defence of the vu
lnerable brood against predators, including conspecifics, at a develop
mental stage when the fry start to forage outside the mother's mouth.
(C) 1998 Wiley-Liss, Inc.