Analysis of the factors related with mate choice and reproductive success in male three-spined sticklebacks

Abstract

Territorial three-spined sticklebacks moved 5·3 times as far as non-territorial males in 2 min (P < 0·001) and spent 11·1 times longer in aggression in the pools (P< 0·001). Territorial males had slightly higher condition factors than non-territorial males. Condition factor was correlated positively with the gonad mass (P< 0·006), carotenoid concentration (P< 0·006) and the activity of CS in the axial muscle (P< 0·05) and lactate dehydrogenase (LDH) in pectoral muscle (P < 0·003). The male traits best correlated positively with female mate choice were courtship effort (P< 0·001), coloration (P< 0·003) and initial condition (P< 0·025). Courtship behaviour was related to intestine mass (P< 0·018), axial (P< 0·028) and pectoral muscle citrate synthase (CS) activity (P< 0·047); coloration was related to gonad mass (P< 0·037). These muscle enzymes may be involved in ATP generation for sustained activities or in recuperation between bouts of burst activity. Females that choose to mate with assiduously courting males which bear higher CS levels may be choosing individuals that show honestly their good condition and capacity to accomplish reproductive tasks.