While T. navalis looks like a brown worm on the outside, it is actually a bivalve. Its head is covered with two white, tri-lobed shells used to bore into wood. The shells are up to 2 cm long and have concentric ridges. Inside the shell is a hook-like process called a styloid apophysis. The foot is also at the anterior end. At the posterior end are two siphons: incurrent and excurrent. The former is used for respiration and feeding while the latter is where waste and sperm or larvae exit. Paddle-like pallets act as a lid to cover the siphons when not in use. Naval shipworms are about 20 cm in length but can range from 1.5 to 58 cm. They are 1 cm in diameter. Calcareous coverings are secreted from their mantles that coat the burrows they make. Male and female adults cannot be distinguished externally.
Range length: 1.5 to 58 cm.
Average length: 20 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes alike
- Grave, B. 1928. Natural history of shipworm, Teredo navalis, at Woods Hole, Massachusetts. Biological Bulletin, 55 (4): 260-282.
- NIMPIS, 2011. "Teredo navalis, general information" (On-line). National Introduced Marine Pest Information System. Accessed June 01, 2011 at http://adl.brs.gov.au/marinepests/index.cfm?fa=main.spDetailsDB&sp=6000016293.