Evidence that catecholaminergic systems mediate dynamic colour change during explosive breeding events in toads

Abstract

Many animals communicate by rapidly (within minutes or seconds) changing their body coloration; however, we know little about the physiology of this behaviour. Here we study how catecholaminergic hormones regulate rapid colour change in explosive breeding toads ( Duttaphrynus melanostictus ), where large groups of males gather and quickly change their colour from brown to bright yellow during reproduction. We find that both epinephrine (EP) and/or norepinephrine (NE) cause the toads' skin to become yellow in minutes, even in the absence of social and environmental cues associated with explosive breeding. We hypothesize that natural selection drives the evolution of rapid colour change by co-opting the functional effects of catecholaminergic action. If so, then hormones involved in ‘fight or flight’ responses may mechanistically facilitate the emergence of dynamic visual signals that mediate communication in a sexual context.

Current State of Conservation Physiology for Amphibians: Major Research Topics and Physiological Parameters

“…2023, 13, x FOR PEER REVIEW 6 of 18 [32,33]. Researchers have also investigated physiological phenomena related to color changes during reproduction, parenting behavior, and movement [34,35].…”

Regulatory gene network for coffee-like color morph of TYRP1 mutant of oujiang color common carp

“…This color-generating pathway is connected with several metabolic pathways and immune systems by catabolizing two common and central metabolites, such as L-tyrosine and L-DOPA. These two metabolites can influence the interaction and coordination among different cells and components to cause skin pigmentation [ 3 , 13 ].…”