Can male fish from distant species attract females with hidden sex signals?

Date Published: September 30, 2013

Source: Behavioral Ecology

Summary: In different species, males and females use different aspects, whether of their physical or mental personalities, to attract the other gender. Their main goal? To reproduce and pass down their genes to future generations. Human males try to use their muscles and good looks to attract females, while male peacocks use their bright colored and large feathers to attract potential female mates. Fish, on the other hand, use specific olfactory sex signals to grab the attention of their fellow female fish. To avoid captivating the attention of females from different species, male fish "typically have high specificity in their signals and are able to distinguish their own signal” from those of other male fish. The fish can discriminate between the signals of other species that live within the area that they are as well inhabiting, however, when a heterospecific male comes, the females may not be able to resist their odor. In the experiment explained in this paper, Rodolphe E. Gozlan, Dean Burnard, J. Robert Britton, and Demetra Andreou, use Pseudorasbora parva and P. promelas to show whether or not females from one species prefer the odor of males from another species that so not originate or inhabit the geographical area that the females do.

In the experiment, all of the fish were kept on the same feeding schedule and after the males and females were isolated from one another for three weeks, all of the fish were isolated in individual plastic planted aerated aquaria. The tanks that held the male fish were placed with a view of the female fish, giving them incentive to produce their odor stimuli. After about twenty four hours, the water containing the odor stimuli were collected from the tanks and used for the experiment. The females that were used for the experiment, not only came from the two different species, but were also divided into two different groups; preovulatory females and postovulatory females. The females were divided into these two specific groups because the “reproductive state of the female influences the response to olfactory sex signals, where preovulatory females show strong behavioral response to male-derived sex cues, whereas postovulatory females do not.”

By using video cameras to observe the female fish, the scientists were able to see that the preovulatory P. parva females preferred the water with the odor of the P. promelas males and that the preovulatory P. promelas females preferred the water with the odor of the P. promelas males. The postvulatory females on the other hand had no preference between the waters of the P. parva males, the P. promleas males, and the controlled water.

Overall the experiment showed how the odor released by the male fish were important for mating selection because of how the postovulatory females (those fish not looking for mates) were not bias to one of the three waters. In addition, the experiment showed that some species of fish, like the P. promelas species, prefer the males of their own species when choosing from the males in their geographical area, but choose males of other species when choosing between males of their own species and males from other geographical locations.

Citation:

Gozlan, R.E., Burnard, D., Britton J.R., and Andreou, D. 2014. Evidence of female preference for hidden sex signals in distant fish. Behavioral Ecology 25: 53-57.