Why male fiddler crabs feed with their small claw and wave their large claw in the air?

Fiddlers feed by scraping the surface sediment up in their small claws, transferring it to the mouth where the complex mouthparts sift out the organic matter. Males wave their enlarged claw to attract females for mating.

Do crabs attract mates with claws?

Male fiddler crabs are lopsided. Yes, females do prefer males with larger claws. But they also care about how males wave those big claws when they’re trying to attract mates. They prefer faster waving, probably because it indicates a more fit potential mate.

How do male fiddler crabs attract mates?

Fiddler crabs mate every two weeks in summer. Males dig, maintain and defend a tidy, cylindrical burrow. To find a female partner, males stand next to their burrow while females walk past. The males wave their major claw to attract a female’s attention.

Why does a fiddler crab have a waving display?

The waving display is also thought to indicate to females the overall healthiness of the male; a more vigorous display is more difficult to do and thus requires the male to be in prime health condition, which suggests that the male will help produce viable offspring. Male versus male competition also occurs as fighting with the major claws.

Why do male fiddler crabs have bigger claws than females?

Yes, females do prefer males with larger claws. But they also care about how males wave those big claws when they’re trying to attract mates. They prefer faster waving, probably because it indicates a more fit potential mate. That was shown very clearly in an earlier experiment when a robot claw left living crabs struggling to keep up.

What’s the life cycle of a fiddler crab?

Life cycle. General anatomy of a fiddler crab. Fiddler crabs live rather brief lives of no more than two years (up to three years in captivity). Male fiddler crabs use the major claw to perform a waving display as a form of female courtship. Females choose their mate based on claw size and also quality of the waving display.

What makes a fiddler crab a detritivore?

The crab’s smaller claw picks up a chunk of sediment from the ground and brings it to the mouth, where its contents are sifted through (making the crab a detritivore ). After anything edible is salvaged, be it algae, microbes, fungus, or other decaying detritus, the sediment is replaced in the form of a little ball.