Naval shipworm

Teredo navalis

The naval shipworm is not a worm but a bivalve that lives inside submerged wood. Its tiny shell-covered front end drills tunnels while the long body feeds and breathes inside the tunnel.

Not a fish · an aquatic neighbor

Water

Saltwater + Brackish

Submerged timber, driftwood, pilings, docks, and wooden ships in marine and estuarine water.

Temperature

15–25°C · 59–77°F

This is the reported optimal temperature range, not a universal survival range.

Size

Usually about 20 cm (8 in) long; reported range 1.5–58 cm (0.6–23 in)

A typical adult is about as long as a pencil

Lifespan

About 1–3 years.

Life expectancy varies with place, conditions, and what scientists have been able to observe.

01 · Signature adaptation

What does it do?

Larvae swim freely until they settle on wood and transform into adults. Adults remain in their tunnels, changing direction when they approach a neighboring tunnel or the end of the timber.

Its superpowerSymbiotic bacteria help it digest a diet made mostly of wood.

02 · Home coordinates

Where does it live?

Now widespread in temperate and tropical seas, including the Atlantic, Pacific, Baltic, and many coastal regions reached through shipping.

Regions: Atlantic Ocean · Pacific Ocean · Baltic Sea · Global introduced range

03 · The menu

What does it eat?

Its shell scrapes wood into particles, while cilia move the particles toward the mouth; siphons can also collect plankton.

Wood-eater and filter feeder: wood particles, phytoplankton, microbes.

04 · Remember this

Two wow facts

A clam in disguise

Although its body looks worm-like, its drilling end carries two small bivalve shells.

Sources [1] [2]

Living wood drill

It lines its burrow with a hard calcareous coating that helps protect and support the tunnel.

Sources [1]