London, Apr 18 (ANI): A longer willy doesn't ensure successful fertilisation, at least in case of male barnacles- the hermaphroditic filter-feeders, according to a new study.
The animals are capable of growing their penises up to eight times their body length.
But the new study has shown that stouter members are sometimes more effective for mating.
The researchers think that by sticking to a rock all through the year without being able to self-mate, the barnacle's lengthy penis increases its odds of spreading its seed.
The animals are known to regrow their penises each year, just before their brief mating season.
Also, water conditions have been found to play an important role in shaping the budding penis.
In calm waters, acorn barnacles grow long, flexible members in order to reach as many mates as possible, while in choppier waters, they develop more muscular penises with far less reach.
"It's kind of like toughness versus flexibility," New Scientist magazine quoted J. Matt Hoch, a marine biologist at Stony Brook University in New York, as saying.
Hoch tested whether barnacle penis plasticity actually affects reproduction, for which he set up two experimental barnacle beds - one on the wave-exposed Atlantic shore and the other in a protected harbour near his university.
After the mating season, he counted up the number of fertilised eggs.
It was found that barnacles raised in calm waters that grew thin, flexible penises struggled when forced to mate in choppier waters and even fertilised significantly fewer eggs than their lengthy counterparts that stayed in calm waters.
In contrast, barnacles with thicker penises fertilised just as many eggs in the harbour as they did in the open ocean.
But, it was the barnacles with thin penises mating in calm waters that fertilised the most eggs out of all the groups.
In fact, the researchers pointed out that in rough waters, barnacles with thin penises suffered fewer injuries and breaks as compared to barnacles with more muscular members.
He explained the above tendency by saying that the waves were so rough at times that the barnacles with thin penises didn't dare come out to look for a mate. (ANI)