Male Brook Sticklebacks' (Culaea Inconstans) Response to Olfactory Cues

Abstract

Male brook sticklebacks were capable of recognizing and discriminating between the scent from nesting, conspecific males and ovulated, conspecific females. In recognition trials, they spent more time near the female, thannear the male scent. Males spent more time near the male scent during the choice trials because they decreased the amount the amount of time spent near the female cue. Male brook sticklebacks were capable of recognizing and discriminating between the scent from ovulated conspecific and heterospecific (Gasterosteus aculeatus) females. They were not attracted to the scent from the heterospecific, but they did spend more time near the surface and direct more surface nudges towards the stimulus drip, indicating that they recognized the cue on some level. When the cues were presented together, males spent more time on the conspecific side. Males only directed courtship pummels towards the female-based cue. The intensity of pummeling can be arranged as: number to conspecific female >> number heterospecific female > number to conspecific male or water control. The number of courtship pummels directed towards the conspecific female stimulus decreased significantly when the odour of a conspecific male or heterospecific female was present. This paper contributes to the growing database demonstrating that courtship communication in gasterosteids is multimodal, encompassing (minimally) visual and olfactory components.