Intraspecific interactions and the function of courtship in mygalomorph spiders: a study of Porrhothele antipodiana (Araneae: Hexathelidae) and a literature review

This is the first comprehensive behavioural study of intraspecific interactions of Porrhothele antipodiana , a large web‐building mygalomorph spider which is endemic to New Zealand. A special posture in which the spider raises its body and extends its fangs (“gaping display”) appears to be primarily an antipredator defence and is only infrequently adopted by P. antipodiana in intraspecific interactions. P. antipodiana uses eight major displays (chewing, grappling, clasping, nipping, palpating, probing, stabbing, and tugging) during intraspecific interactions, palpating being predominant. Males use claspers on legs I to hold onto females during copulation. Females become passive when clasped. Cannibalism is rare; when it does occur, males kill females about as often as females kill males. From comparison of results from a variety of testing procedures, there is no evidence that studying interactions of P. antipodiana in the laboratory seriously distorts this species’ behaviour. The literature on intraspecific interactions, especially courtship, of other mygalomorphs is reviewed. The function of mygalomorph courtship is discussed, special attention being given to the significance of cannibalism and the role of the male’s behaviour of clasping females.