A TYPE of crab that plays the gentleman by adopting a “ladies first” policy has been unmasked as a sex abusing cad.
Male banana fiddler crabs have been observed standing aside from their burrows to make way for the female they are courting.
Once inside, she is trapped and forced to have sex.
Researcher Patricia Backwell, from the Australian National University in Canberra, said: “Mate-searching female fiddler crabs are fussy about the quality of a male’s burrow, so they enter it to check its suitability as an incubation site before selecting the male as a mate.
“Some males trap the female inside, coercing them to mate,” she said.
The crabs were studied in Darwin, Australia, over two mating seasons.
Competition for mates is fierce among male banana fiddler crabs, and a female may consider up to 20 suitors before making her choice, said the scientists.
Males generally entered burrows before the female, but in some cases courting males were seen to step aside at the entrance to let the female enter first.
When this happened, most females refused to go in. Those that did enter a burrow first were more likely to mate and lay eggs.
Male courting behaviour in other crab species includes pinning the female to the ground or grabbing her and holding her in place.
The research appears in the journal Public Library of Science ONE.