Marine biologists working off the coast of the Philippines have captured an image of an incredibly elusive sight — a free-swimming oceanic shark giving birth.
Along with colleague A. E. Bicskos Kaszo, the extraordinary photo was taken by Simon Oliver from the University of Chester, who told the BBC that this was "the first record of any oceanic species giving birth," adding the caveat that it's "always difficult to say definitively."
In a paper that now appears in the journal Coral Reefs, Oliver describes how it happened:
At 0628 hrs [on April 4, 2013], during a biological survey of Monad Shoal...we observed a large female pelagic thresher shark swimming back and forth across a cleaning station in an agitated state. We were unable to decipher the cause of the shark's distress from our observation post 15 m away, although it was evident that cleaner wrasse were taking bites from its pelvic region. We observed the shark for a total of 4 min, during which we took its photograph for identification purposes. The shark then left the cleaning station and was not observed again. Later, when we processed the photograph for analysis, it revealed the head of a pup emerging from the shark's cloaca.
Thresher sharks are known for their elongated rear fin, which they use for hunting purposes:
[ Via BBC ]
Top image: A. E. Bicskos Kaszo.