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Six male sharks found by this researcher turned out to be pregnant. What’s going on?

Sand tiger sharks use shipwrecks for homes in North Carolina’s ‘Graveyard of the Atlantic’

Sand tiger sharks in North Carolina and along the broader east coast of the USA help track shark movement and behavior over time.
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Sand tiger sharks in North Carolina and along the broader east coast of the USA help track shark movement and behavior over time.

The discovery of seven sharks with both male and female sex organs has one marine researcher convinced “there is something going on with sharks,” according to Science News.

Six of these seven hermaphrodite sharks were pregnant, too, Alissa Barnes reported during a session at the 5th International Marine Conservation Congress on June 25.

All seven of the sharks were bigeye houndsharks, pulled from waters off the northeastern coast of India, according to a synopsis of her research called “Elasmobranchs through the Looking Glass.”

Bigeye houndsharks are a small, deep water shark, typically found in a stretch of ocean from Israel to southwestern India, according to Marine Species Identification portal. In India, they are a popular seafood catch, says the site.

Barnes’ discovery came as she worked to figure out what’s driving a decline in shark fishing stocks in that region, says a second report she submitted.

“Externally, these specimens appeared to be immature males that (had) visible stomach bulge,” she wrote.

The bulge turned out to be shark pups in six of the seven cases, she said, adding that all the males had penises and “fully developed female sex organs.” She calls it “intersexuality,” in her report.

While hermaphroditism has long been studied in other large fish species, it “is very uncommon in sharks,” shark biologist Colin Simpdendorfer of Australia told Science News.

Barnes told Science News the anomaly might be caused be pollution, though some marine biologist are already disputing that on social media. Those critics don’t have a guess of their own, however.

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“There is a growing need to understand this phenomenon and its underlying causes,” she wrote in her study.

Experts tell a male from a female sharks by the sperm-delivering claspers on their underside, which is like a penis, reports TheFisheriesBlog.com

“Claspers: male sharks; No claspers: female shark,” Barnes wrote.

Stranger things have happened with sharks, experts say.

National Geographic reported in 2002 that a female white spotted bamboo shark perplexed experts at a Detroit aquarium with a virgin birth. “She hadn’t been near a male for six years,” National Geographic said at the time.

Nature finds a way, as they say in the “Jurassic Park” movies.

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Mark Price: 704-358-5245, @markprice_obs
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