While many animals are known to be able to reproduce asexually, rarely are animals able to switch from sexual reproduction to asexual reproduction after already having mated at some point in their lives. A shark at an aquarium in Queensland has done just that, and scientists don’t know how she did it. The zebra shark, Leonie, gave birth to three adorable little pups the aquarium has named Cleo, CC, and Gemini.
In a few extremely rare cases, sharks have been known to birth pups asexually through a process known as parthenogenesis wherein unfertilized eggs mature as though they were fertilized. However, parthenogenesis has never been observed in a shark which had previously mated. To help solve this mystery, the aquarium called in genetics researchers from the University of Queensland to take DNA “fingerprints” of Leonie’s pups and determine what their genetic makeup was like. Researchers published their findings in Nature after they were amazed to discover that the pups only had Leonie’s DNA, ruling out the possibility that she had stored sperm from her previous mate.
According to lead researcher Christine Dudgeon, the discovery is some much-needed good news in light of recent declines in worldwide shark populations:
This has big implications for conservation and shows us how flexible the shark’s reproductive system really is. What we want to know now is could this occur in the wild and, if so, how often does it? One reason why we haven’t seen it before could be because we haven’t been looking for it. It might be happening in the wild but it’s never been recorded in this species before.
With so many unexplained mass deaths of sea life occurring around the world with increasing frequency, Leonie’s strange birth gives some hope to Dr. Ian Malcolm's infamous epigram that life, uh, finds a way. Leonie sure did.