For the first time , a shark that previously reproduce in the common personal manner has been observed using virgin birth , or asexual reproduction , to produce healthy materialization . The surprising event has present marine biologists a chance to learn about the evolutionary basis for doing without sex .
A zebra shark ( Stegostoma fasciatum ) named Leonie has been kept at Townsville ’s Reef HQ Aquarium since 1999 after being caught in the natural state . Zebra sharks are endangered , so when Leonie was put in a tank with a male of her species , aquarium staff were pleased that it lead to infant sharks for six successive years .
After more than a dozen babe , however , space was develop scurvy and the aquarium separated the pair , putting Leonie in with one of her daughters . Although that block Leonie ’s upbringing for a year , in 2014 Leonie repose eggs . None hatched , but in the 2015/16 breeding season , Leonie produced three healthy daughter .
Female shark can sometimes store sperm for foresightful geological period of time after mating , but hereditary analysis of these offspring publish inScientific Reportsshows that they are identical to Leonie , with no input from her former mate . On the other hand , the shark stick out when Leonie was housed with the male have been confirmed as compound the genetics of the two parent .
Although such a shift to asexual reproduction has been confirm before in an bird of Jove ray and a feather boa constrictor , this is the first make love lawsuit in sharks . First authorDr Christine Dudgeonof the University of Queensland say in astatement : “ This has boastful implications for conservation and shows us how flexible the shark ’s reproductive system really is . Leonie adapted to her circumstances and we believe she switched because she miss her mate . What we need to bed now is could this pass off in the wild and , if so , how often does it ? ”
The writer noted that some invertebrate flip their replication scheme based on temperature , but that could not have been the caseful here .
Parthenogenesis is used by flora and many invertebrate . It is never seen in mammalian , and while it does take place in reptilian and fish , it is guess to be rare among vertebrate because the release of genetic variety make metal money that rely on it vulnerable to parasites and changing environments . However , Dudgeon and her co - authors note the capability to exchange might be useful for cases where female have expanded into young territory and ca n’t find mate , leave them to produce offspring for a coevals or two while waiting for the males to catch up .
They mark this may occur more often than we pull in , since it would be hard to notice in the state of nature , and some eccentric in captivity might have been wrongly assume to take spermatozoan storage . Nevertheless , Dudgeon say IFLScience that the only shell where the “ signature of parthenogenesis ” has been seen in the genetics of wild shark or rays has been in thesawfish , where overfishing may have made it hard for females to find mates .
Dudgeon told IFLScience the team are very keen to see whether the daughters produce offspring and , if so , how . “ There ’s never been a documented case of a vertebrate species where young produced through this sort of parthenogenesis pass on to procreate sexually , ” she said .
Reef HQ has no programme to rename the shark Mary .
