Wednesday , January 27 2021

VIDEO: 'Virgin' shark gives birth to a baby

A lone female shark that gave birth to a pup on January 3, which was eaten by a tank mate two days later, has left the staff at a Urangan aquarium fishing for answers.

The nervous whaler shark came from Fraser Coast waters about six years ago and has lived alone in the times of the reptworld tank during that time.

Despite the pup's unfortunate run in a hungry cod or groper, University of Sunshine Coast doctor and animal ecologist Dominique Potvin said the "virgin birth" was still a fascinating event.

Known scientifically as parthenogenesis, Ms Potvin said the process was a rare occurrence in vertebrate species.

It is common in invertebrate species like stick insects and other fish but not sharks. "It's pretty incredible and it is very rare because all the stars need to align for this to happen," Ms Potvin said.

"It does happen but we have not known about it in sharks that long.

"Essentially, if a female senses that a man has not been around for a really long time sometimes his body will try and reproduce anyway.

"Normally this was not working but sometimes the little egg cell finds what's called a sister polar body, which is kind of like two cells coming together instead of an egg or a sperm."

Ms Potvin said baby sharks born from this genetic process can be disadvantaged, with a low chance of survival.

"The problem is, once it does happen, the baby will only have genetics of one half of what it is is to suppose to have … with no mixing of genes it is the most inbred you can be

"Being eaten by a groper is one thing but it may not have been that long anyhow."

In the last 30 years of the family run business, Greg Wolff has seen local coral and a lone sea snake reproduced by himself but never a shark.

"It's quite surprising indeed and it's funny because when you google the information as to it happened, it does not really line up," he said.

"They all say sharks hold semen inside for four years and things like that but she has been here too long than that

"A lot of things happen here that marine biologists have shake their heads at … the number one thing is keeping the coral alive, living and growing in the tanks.

"That's kind of got something that has been some of the marine biologists to get their heads around, but it works."

The baby shark was eaten two days after birth, possibly by a cod.

The baby shark was eaten two days after birth, possibly by a cod. CONTRIBUTED

As for the demise of the pup, Mr Wolff said it was anyone's guess as to whom the hungry culprit was and – without any notice.

"It's just one of those things … she was in a captive environment and we did not go out of our way to breed, next thing she's got a pup in the water and we did not really have her anywhere else to put her . "

"Unfortunately I guess one of the cods decided that they liked her more.

"We do not know exactly who, but there are only a couple of fish in there that are completely full of sharks."

Mr Wolff said the aquarium is open every day of school holidays, with staff only a very happy visitor for a visit and greet with their star shark.

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