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

Territorial three-spined sticklebacks moved 53 times as far as non-territor ial males in 2 min (P<0.001) and spent 11.1 limes longer in aggression in t he 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 activ ity of CS in the axial muscle (P<0.05) and lactate dehydrogenase (LDH) in p ectoral muscle (P<0.003). The male traits best correlated positively with f emale 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) a ctivity (P<0.047); coloration was related to gonad mass (P<0.037). These mu scle enzymes may be involved in ATP generation for sustained activities or in recuperation between bouts of burst activity. Females that choose to mat e with assiduously courting males which bear higher CS levels may be choosi ng individuals that show honestly their good condition and capacity to acco mplish reproductive tasks. (C) 2000 The Fisheries Society of the British Is les.