Social cohesiveness of convict cichlid fish (Cichlasoma nigrofasciatum Guenther) after irradiation of parental spermatogonia and oogonia with different doses of X-rays

1980 ◽  
Vol 10 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Johannes Horst Schr�der
Behaviour ◽  
1978 ◽  
Vol 65 (1-2) ◽  
pp. 138-160 ◽  
Author(s):  
Hay Thomas F.

The convict cichlid fish, Cichlasoma nigrofasciatum, exhibits extended parental care in both the laboratory and the field. Families of this species were observed in Lake Xiloa', Nicaragua, during part of the breeding season. Young fry (less than 5 days free swimming) could be induced to follow a variety of "dummy" parents when their own parents were restrained at a distance. Older fry fled the dummies in the same manner as they fled predators. Two laboratory experiments were conducted to analyze further the responses of convict cichlid fry to parental dummies. Experiment I demonstrated the following: 1. Fry showed consistent preferences in tests with 5 pairs of mechanically moved dummies. Some of these preferences involve species characteristic cues. 2. Responsiveness to dummies increased over time within a test and over repeated tests. Responsiveness changed non-monotonically with age; those tested at 1 to 3 days free swimming were most responsive, 6 to 8 day old fry were least responsive and 14 to 16 day old fry showed intermediate responsiveness. 3. Preferences were weaker in the older, less responsive fry but were generally in the same direction as in younger fry. Experiment II tested the effects of experience with a particular dummy on the preferences demonstrated in Experiment I. For all ages and for most dummy pairs there was a significant interaction between training condition (preferred vs non-preferred dummy) and preference. Experience with a single dummy also resulted in a general increase in responsiveness to the two dummies in the preference test. The present results are discussed in terms of selection pressures presumed to operate on natural populations of C. nigrofasciatum and also in terms of research on "imprinting" in precocial birds.


Behaviour ◽  
1994 ◽  
Vol 129 (1-2) ◽  
pp. 63-77 ◽  
Author(s):  
James D. Kieffer ◽  
Robert J. Lavery

AbstractAnimals may provide more care for their young under certain environmental conditions. For instance, if food is plentiful parents may invest more in the current brood than if food is scarce, assuming that food abundance is correlated with parent and offspring condition. In this experiment, we manipulated food levels (low vs high) for both parents and offspring to determine if parental care is influenced by parental and/or offspring condition in the convict cichlid, Cichlasoma nigrofasciatum. Parents which were fed a higher ration gained weight, whereas parents fed a lower ration lost weight. Similarly, young which were fed a higher ration were significantly larger than young fed a lower ration. Parents which were fed a higher ration defended their brood more vigorously than parents fed a lower ration. Offspring condition had little effect on parental care. Furthermore, females consistently invested more than males. The results show that parental convict cichlids adjust care in response to their own food supply rather than that of their offspring.


1978 ◽  
Vol 56 (6) ◽  
pp. 1367-1371 ◽  
Author(s):  
G. J. FitzGerald ◽  
M. H. A. Keenleyside

Basic reproductive and behavioral data were collected from pairs of Cichlasoma nigrofasciatum breeding under controlled conditions. Increasing the density of potential breeding pairs increased the level of territorial aggression and decreased reproductive success. Time spent with their young by parents did not vary consistently with density. The importance of the increase in aggression and its possible influence on reproductive success are discussed.


Ethology ◽  
2010 ◽  
Vol 71 (3) ◽  
pp. 187-200 ◽  
Author(s):  
Gabriele Siepen ◽  
M.-Dominique Crapon de Caprona

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