Shark female found to hold sperms for almost 4 years

Washington, January 11: Biologists from the California Academy of Sciences have found a shark egg case dropped by an adult bamboo shark that has signs of healthy development. The scientists had good reason for surprise as the Steinhart Aquarium’s female shark adults had spent nearly four years – 45 months – in complete isolation from males! The young shark most likely inherited this “mystery” genetic material from its father – an unknown male from the aquarium. “Long–term sperm storage – where a female can delay fertilisation for months or even years after mating – is a remarkable adaptation that helps promote genetic diversity,” said Luiz Rocha, curator at ichthyology department of California Academy of Sciences. This is the first documentation of long–term sperm storage in brown banded bamboo shark (Chiloscyllium punctatum). After mating, some female sharks can store sperm in the tubules near their oviduct – reproductive area that helps produce the jelly–like substance surrounding fertilised shark eggs. (IANS)