In this age of over-exposure and cameras seemingly located on every corner, "mystery" is quite rare now-a-days. But this is more of a terrestrial occurrence than an aquatic one. For instance, we've explored more of our orbiting moon's surface than we have of Earth's deep seas. This week, one such mystery was captured in a still-frame―a mother thresher shark giving birth to her pup.
"[T]he first record of any oceanic species giving birth," said Dr. Simon Oliver from the University of Chester. "One of [our team] is a photographer―Attila Kaszo. He took the picture of the shark, and when he processed the image and showed it to me, I freaked out."
The photograph was recently published in Journal of the International Society for Reef Studies.
Thresher sharks are large pelagic organisms (preferring to roam the open oceans) that primarily feed on small-to-medium sized fish. The common name "thresher shark" is actually an umbrella taxonomy, referring to three extant species of the genus Alopias: the pelagic, bigeye, and common thresher shark. Given the open ocean backdrop and geographic description where the animal was photographed, it can be intelligently inferred that the shark pictured giving birth is indeed a pelagic thresher shark (Alopias pelagicus).
"It may well be, or at least the first time that the event has been photographed, but this is always difficult to say definitively," Oliver says.
Thresher sharks received their ubiquitous name by their predatory habits. Unlike any other known shark species, thresher sharks will us their whip-like tail to swat-and-swipe at schools of fish, stunning the impaled individuals. Once the stunned individuals are located, the thresher shark then consumes the still-alive prey.
Like numerous shark species today, thresher sharks are under great commercial threat. Millions-upon-millions of these cartilaginous fish are "finned" each year for the culinary trade. Finning is the practice of cutting-off the fins of still-living sharks, then throwing their mutilated bodies back into the ocean to squirm-and-sink to the bottom, dying of blood loss and/or suffocation.
All three thresher shark species are listed as either "Threatened" or "Vulnerable" to extinction by the IUCN Red List of Threatened Species.
