The inheritance of aggressiveness in the convict cichlid fish, Cichlasoma nigrofasciatum (Pisces: Cichlidae).
Intraspecific comparisons in aggression were made between X-irradiated (2 times 500 R) ancestors and untreated control animals. Bites delivered to sub-adult conspecifics were counted to measure aggressiveness. When compared with corresponding controls, a significant reduction in male aggressiveness was found in the post-irradiation F1 generation. A greater variation in bites delivered occurred among the F2 post-irradiation generations than among the control equivalents. Three distinct back-cross generations were obtained as follows. a single F1 female from the irradiated line was mated to (a) her high aggressive (I-A) and (b) her low aggressive (I-NA) F2 son; a F1 control female was mated to her low aggressive F2 son. In the back-cross generations, both I-A and C-NA males were more aggressive than I-NA males. No differences were found between I-A and C-NA back-cross males. The findings are discussed in terms of a two-factor model based on Mendelian laws.
D000374:Aggression; D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D005399:Fishes; D006066:Gonads / Q000528:radiation effects; D006801:Humans; D008297:Male; D011830:Radiation Effects; D012737:Sex Factors