Smaller fishes prefer bigger, bossier fishes for protection

TORONTO - Smaller fishes of the cichlid group prefer bigger, bossier ones for company and protection from other predators.

“It seems that cichlids potentially prefer groups of dominant members for reasons of survival due to the increased protection from predation,” says Marian Wong, study author, post-doctoral fellow in psychology, neuro-science and behaviour at McMasters University.

A team from McMaster University and University of New South Wales has found that among cichlids, a species that lives in groups, members make strategic decisions about their living situation.

The helper class of cichlids showed a preference for joining groups of familiar individuals, some likely to be family members.

But when given the choice between unfamiliar social groups the helpers chose groups where the members were bigger and bossier. In other words, fish — like humans –understand that membership has its rewards.

At the beginning of the experiment, which was conducted in Zambia’s Lake Tanganyika, researchers expected that individual cichlids would base their group-living arrangements on whether they could improve their social rank and thereby expedite their attainment of breeding status.

However, when faced with a choice between unfamiliar groups they chose the group that did not enhance their rank but that contained larger group members, says a McMaster’s release.

The results appeared in the current issue of Biology Letters.