First living 'giant shipworm' found in the Philippines: study

Trishia Billones, ABS-CBN News

Posted at Apr 18 2017 02:50 PM | Updated as of Apr 18 2017 04:21 PM

A woman looks at a photo of a giant shipworm, a story of which was published by Hong Kong newspaper South China Morning Post. The daily reported that scientists found a "mysterious meter-long clam" in the Philippines. ABS-CBN News

MANILA - The first known living sample of an ancient mollusk known previously only by its shells was discovered in a lagoon in the Philippines, international reports say.

Named the giant shipworm, the 'Kuphus polythalamia' species was only known to humans by the ginormous shells they left behind, which was often similar in size and shape to a baseball bat and were known to grow to "stunning heights," according to Popular Science.

"It was a very mysterious organism," Dan Distel of Northeastern University’s marine science centre, co-author of the study published in the journal PNAS, told The Guardian.

Although the scientists knew of the giant shipworm for centuries, the creature had been elusive until a local documentary featured natives cooking and eating it.

The footage led international researchers to an unnamed site, which Popular Science described as "Kuphus polythalamia paradise: the stinky lagoon of a long-abandoned log farm."

Researchers retrieved five specimens from the area, according to online magazine The Verge, and scientists painstakingly chipped the giant shipworms out of their shells and dissected them.

The study did not identify the location of the shipworm specimen over fears that the public will mob the area. 

But Distel described the shipworm's "gunmetal-black" color as "shocking" to The Guardian, since most bivalves are greyish, tan, pink, brown, light beige.

He also described the specimen as "much beefier, more muscular than any other bivalve I had ever seen.” 

WHAT IS A GIANT SHIPWORM?

Online publication New Scientist reported that the giant shipworm is the "world’s longest bivalve and the only known extant species of its genus."

While other shipworm species typically inhabit and eat driftwood, the giant shipworm, which is actually a clam, lives in organic rich, noxious mud inside a long tube made of calcium carbonate which it secretes.

The animal relies on symbiotic bacteria in its gills instead of feeding, the article added, as the bacteria break down the mud’s hydrogen sulfide. This gives the shipworm’s habitat "a distinct rotten egg smell, and produce organic carbon, feeding their host."

“If they want to grow, they have to open that end of that tube, so somehow dissolve or reabsorb that cap on the bottom, grow, extend the tube down further into the mud, and then they seal it off again,” Distel told The Guardian.

He added, the creature's body "has been stretched out through evolution so that it no longer fits between the two shells."