Subterranean Fishes of the World

5629

2022

AIM 2022

35

Animals display remarkable diversity in rest and activity patterns that are regulated by endogenous foraging strategies, social behaviors and predator avoidance. Alteration in the circadian timing of activity or the duration of rest-wake cycles provide a central mechanism for animals to exploit novel niches. The diversity of the >3000 cichlid species throughout the world provides a unique opportunity to examine variation in locomotor activity and rest. Lake Malawi alone is home to over 500 species of cichlids that display divergent behaviors and inhabit well-defined niches throughout the lake. These species are presumed to be diurnal, though this has never been tested systematically. We are measuring sleep and locomotor activity across the circadian cycle in different species of Lake Malawi cichlid species. To date, these studies have identified surprising variability in the timing of locomotor activity including highly diurnal and nocturnal species. In addition, we have significant variability in sleep duration. We are currently extending these studies to examine how environmental variables including mouth brooding and social dominance regulate sleep and activity across cichlid species. The identification of locomotor and sleep variability in Lake Malawi cichlids provides a system for investigating the molecular and neural basis underlying behavior variation, and how ecology and environmental history shape these traits.

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