Responses to conspecific and heterospecific olfactory cues in the swordtail Xiphophorus cortezi

Female Xiphophorus cortezi responded to olfactory cues from both conspecific males and heterospecific X. nigrensis and X. montezumae males when given a choice between the stimulus and water. When given a choice between the conspecific and heterospecific cues, however, females demonstrated a strong preference for the conspecific stimulus. Of the two heterospecific species, females responded more strongly to their close relative X. nigrensis than they did to the more distantly related X. montezumae. Mate recognition in northern swordtails is evidently not a simple process based upon a response to one variable, but the outcome of complex responses to information from at least both visual and olfactory cues. (C) 1997 The Association for the Study of Animal Behaviour.