Male sand gobies show their feminine side

GAINESVILLE, Fla., May 6 (UPI) -- A male sand gobie off the European coast knows the best way to attract females is to show he can act like a good dad, even if he's a bit two-faced about it.

Sand gobies are small fish native to the European coast and are among about 20 percent of fish families worldwide that display some form of care for eggs or hatchlings.

Researchers from Canada, the United States and Finland reported in the current issue of the journal Behavioral Ecology that male sand gobies work harder at building nests and taking care of eggs when females are present -- the first time such "courtship parental care" has been documented in any species.

But when the moms aren't around, it's a different story. Unaccompanied male sand gobies not only shirked their parental duties, they were more likely to gobble down entire clutches of eggs.

"We were interested in whether males would change their behavior in response to the perception that their future mating opportunities were different," said Colette St. Mary, an associate professor of zoology at University of Florida and one of three authors of the paper. "We found this was the case."