A field study of territorial and reproductive behaviour of the cunner, Tautogolabrus adspersus, in Conception Bay, Newfoundland

Abstract

Territorial and reproductive behavior in the cunner, Tautoglabrus adspersus ( Walbaum ), were observed in Conception Bay, Newfoundland. Cunners are active from May until November and spend the winter months in a state of torpor in the substrate. Males more than 6 years old establish territories in early June. Territories are defended outside the mid-summer spawning season. Both territorial arid nonterritorial males of >150 mm TL acquire nuptial colouration between emergence from overwintering torpor and the start of the spawning season. Nonterritorial males are vigorously excluded from territories by the resident males and appear to contribute little to the reproductive effort of the population. Territorial females are found in the peripheral areas of some males’ territories and-exhibit aggressive behavior toward other's females. Both territorial and nonterritorial females pair spawn with territorial, males. Fish of both sexes are capable of multiple spawns. Group spawning by nonterritorial cunners was not observed. The function of territory defense in T. adspersus is discussed.