Dwarf Smoker Photo: Kolm et al. Current Biology
Reading Male Dwarf Smokers seduce their females with a bizarre system of mating: A fishy appendage to their gill covers imitates food. The shape of the bait depends on the favorite food of the females in their respective habitat, as Swedish biologists have now documented. The males lure demanch either with the dummy of an ant or a beetle. According to the researchers, the females respond to the bait as if it were real food: they bite and nibble at the curious appendage. This, in turn, gives the male the opportunity to come within range of the opposite sex and transfer his semen. These curious lock methods were already known, but the Swedish researchers have now observed that the shape of the bait is variable within the species and is based on the favorite food of the female.

In one experiment, the scientists used a group of females to eat ants. Then they put two males in the aquarium. The bait of one resembled an ant, the other a beetle. As the researchers had suggested, the females who had become accustomed to ants nibbled on the bait of the male with the appropriate dummy.

This explains why the baits of males can look very different along different river sections.
Thus, they form a bait that resembles an ant, if these creepy-crawlies belong to the preferred food of the ladies in their respective habitat. If, on the other hand, they live in a region where beetles are the main determinants of the diet, the fishmongers take advantage of this particular attraction. Ultimately, they increase the chances of getting going, the researchers say.

The up to seven-centimeter-long Dwarf Smoker is native to South American waters, and feels most comfortable in the well-flowing rivers of Trinidad and Venezuela. He belongs to the family of the Salmler and prefers to eat ants, beetles and other small insects that swim on the water surface. display

Niclas Kolm (Uppsala University) et al .: Current Biology, doi: 10.1016 / j.cub.2012.05.050 © science.de? Sabine Short

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