Size: Adult Teredo navalis ranges in length from 20 cm to as much as 50 cm in warmer waters. Its circumference is not more than four centimeters.
Shell: While technically a bivalve, its bivalve shell is reduced to a small grinding device on its anterior end responsible for boring through wood, making it appear as a small white worm with a helmet. This amber-colored helmet-shaped shell is 2 cm long; the sharp ridge at the end is responsible for boring through the wood.
Other organs: The shell plates on its anterior work in tandem with the posterior muscles to bore through the wood that it lands on. The pallets at the posterior end (made of hard shell material) close a burrowed Teredo navalis off from its environment, keeping both potential predators and water with intolerably low salinity from entering its burrow.
Posture: Its typical posture is either a boring posture (if it does not already have a hole in the ship to stay inside) or a posture suited to the shape of the hole in the ship in which it lives.
Sex Dimorphism: There is no significant sexual dimorphism beyond the mantle cavity of the female in which the larvae hatch (Turner 1966: 32-40).
No one has provided updates yet.