QUEZON CITY, Philippines (Apr 2026) — A strange, rock-eating creature found only in Bohol is now in the running for a global title, and it might be one of the weirdest animals you will ever hear about.
Locally called antingaw, the species Lithoredo abatanica is one of five finalists for the International Mollusc of the Year. Unlike typical clams, this rare organism survives by boring into and consuming limestone, something no other known shipworm does.
Not your usual “clam”
Despite its nickname, the antingaw is not your typical shellfish. Shipworms are actually a type of clam, but they look more like elongated worms with tiny shells at one end of their bodies.
Most shipworms feed on wood, which is why they are often found damaging boats and mangroves. The antingaw breaks that pattern. It has evolved blunt, ridged shells that act like tools for grinding through rock instead of wood.
Researchers confirmed this unusual diet after finding limestone inside its digestive system. That makes it the first known freshwater invertebrate capable of eating rock.
A mystery scientists still can’t fully explain
How the antingaw gets nutrients from stone remains unclear. Scientists suspect it relies on symbiotic microorganisms living in its gills, similar to how other shipworms depend on bacteria to digest wood.
This unusual biology has caught the attention of researchers at the University of the Philippines Marine Science Institute, who are continuing to study the species.
Their work is part of a broader effort to explore shipworms and their microbial partners for possible medical and industrial applications. The project, backed by the Department of Science and Technology, looks into compounds that could lead to new therapies.
Why this tiny creature matters
Winning International Mollusc of the Year is more than just a title. The prize includes full genome sequencing, which could unlock valuable insights into how the antingaw survives in such an extreme way.
That genetic data may help scientists develop new biotechnology products, especially those involving novel enzymes or compounds.
For the Philippines, it is also a chance to spotlight a unique species found nowhere else on Earth. The antingaw lives exclusively in the Abatan River in Bohol, making it both rare and distinctly local.
Voting is open to the public
The competition is organized by international research groups, including the Senckenberg Society for Nature Research and Unitas Malacologica. Entries from Italy, Australia, Seychelles, and the United States are also in the running.
Public voting will determine the winner, with the deadline set for April 26.
Those interested can support the Philippine entry by voting through the official competition website.
