Olfactory mate recognition in a sympatric species pair of three-spined sticklebacks

Abstract

Mate recognition is critical to the maintenance of reproductive isolation, and animals use an array of sensory modalities to identify conspecific mates. In particular, olfactory information can be an important component of mate recognition systems. We investigated whether odor is involved in mate recognition in a sympatric benthic and limnetic species pair of three-spined sticklebacks (Gasterosteus spp.), for which visual cues and signals are known to play a role in premating isolation. We allowed gravid females of each species to choose between water scented by a heterospecific male and water scented by a conspecific male. Benthic females preferred the conspecific male stimulus water significantly more often than the heterospecific male stimulus water, whereas limnetic females showed no preference. These species thus differ in their odor and may also differ in their use of olfaction to recognize conspecific mates. These differences are likely a consequence of adaptation to disparate environments. Differences in diet, foraging mode, habitat, and parasite exposure may explain our finding that odor might be an asymmetric isolating mechanism in these sympatric stickleback species.

Habitat-dependent olfactory discrimination in three-spined sticklebacks (Gasterosteus aculeatus)

“…Here, stickleback males from clear-water habitats exhibited the stickleback typical red courtship coloration that has been shown to be decisive during courtship, mate-choice and male-male aggression (see Bakker and Milinski 1993), while sticklebacks from tea-stained habitats only had a dull courtship coloration but courted more vigorously, supposedly to compensate for the reduced visibility within their habitat of origin (Hiermes 2008). Furthermore, a study on a limnetic and benthic stickleback ''species pair'' has shown that wild-caught benthic females recognize males of their own species by odor, whereas limnetic females do not; this also corresponds to the ecological conditions and the habitat type of the ''species pair'' with benthics breeding in deeper water (Rafferty and Boughman 2006). Thus, it would be interesting to conduct further experiments offering visual cues or a combination of olfactory and visual cues and compare those again among sticklebacks of both habitat types and investigate whether the environmental lighting conditions indeed promote a differing use of sensory channels as suggested by the current study.…”

Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks

“…Benthics and limnetics from Paxton Lake have documented differences in odour [23]. To examine the role of odour in the development of preference, 13 families were raised by their biological (conspecific) father and exposed them to heterospecific odour during the first 7 days post-fertilization.…”

On the scent of speciation: the chemosensory system and its role in premating isolation

“…Among examples of chemical reproductive isolation, chemical characterization has been achieved mainly in insects, reptiles and plants, in which methods are well established (for example, Gries et al, 2001;Schiestl and Ayasse, 2002;Lemaster and Mason, 2003). In the other groups (rodents, fish, annelids), experiments during which individuals are presented with olfactory stimuli only (urinary stimuli for rodents; water perfumed with odours for aquatic animals) have demonstrated olfactory mate preferences (for example, Smadja et al, 2004;Sutton et al, 2005;Rafferty and Boughman, 2006). In the house mouse, the use of habituation techniques has allowed an indirect assessment of the extent of divergence in urinary signals within and between two subspecies (Smadja and Ganem, 2008).…”