An international research team led by Northeastern University marine biologists has discovered a new genus and species of shipworm burrowing into the bedrock of the Abatan River on the Philippine Island of Bohol.

Shipworms (family Teredinidae) are a group of predominantly marine, wood-boring and wood-feeding bivalve mollusks.

Known in the literature since the 4th century BCE, these creatures are the primary consumers of woody materials across the world’s oceans.

In contrast, the newly-discovered shipworm — named Lithoredo abatanica — lacks adaptations associated with wood-boring and wood digestion.

“Lithoredo abatanica is not a wood-borer and lacks the anatomical and morphological specializations typically associated with wood-boring and wood-digestion in other species,” said Dr. Reuben Shipway of Northeastern University and colleagues.

“It burrows into and ingests limestone, which accumulates in the guts of animals and is expelled from the siphons as fine-grained particles.”

“This strategy of burrowing into rock by ingestion is, to our knowledge, unique among the animal kingdom.”

The specimens of Lithoredo abatanica were collected from deposits of soft limestone in the Abatan River as part of a Philippine Mollusk Symbiont project expedition.

“The shipworms had entirely reshaped the riverbed ecosystem,” the scientists said.

“The rocks at the bottom of the river were covered in holes, many with tiny shipworm siphons protruding into the water.”

“Any burrows the shipworms had abandoned were now home to small fish and crustaceans.”

A paper reporting the discovery was published this week in the Proceedings of the Royal Society B.

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J. Reuben Shipway et al. 2019. A rock-boring and rock-ingesting freshwater bivalve (shipworm) from the Philippines. Proc. R. Soc. B 286 (1905); doi: 10.1098/rspb.2019.0434