Cichlids as a Model System for Studying Social Behaviour and Evolution

Abstract

The complex social behaviour of cichlids has fascinated scientists and hobbyists alike for almost 100 years. In this chapter, we review the breadth and complexity of cichlid behaviour, particularly with respect to social interactions. We present the case that cichlids are one of the best model systems for understanding both the mechanisms and evolution of behaviour. This is due to the fact that cichlids can be observed without being greatly disturbed, both in the aquarium and field and because of the unique opportunity to experimentally manipulate their environment and behaviour. We first give a brief account of the diversity of social systems in the cichlids and the diverse research in this area, from the very early work of authors like Curtis, Noble, and Baerends, to modern studies into the dynamics and structure of social behaviour in these fish. In Sect. 2, we explore the causal factors leading to the evolution of social complexity, discussing the occurrence and evolution of different social systems across ecological and life-history contexts. We investigate the behavioural complexity displayed by cichlids in Sect. 3, including a brief treatment of the different modalities of behavioural interactions. In Sect. 4, we discuss the immense potential for using cichlids as model species in studying social and behavioural evolution, before ending in Sect. 5 with exciting future directions for research employing the latest technical advances in both the laboratory and field.