This won't surprise hobbyists, but it's interesting. I don't know how many times I've sat in front of an aquarium mumbling, "You're three times his size, put him in his place!" when a barely legal Guppy bullies bigger fish.
Scientists at the University of Exeter and Texas A&M University found that when fish fight over food, it is personality, rather than size, that determines whether they will be victorious. Photo: University of Exeter.The study, published in the journal Behavioral Ecology and Sociobiology, found that small fish were able to do well in contests for food against larger fish provided they were aggressive. Regardless of their initial size, it was the fish that tended to have consistently aggressive behaviour - or personalities - that repeatedly won food and as a result put on weight.Fish win fights on strength of personality