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Shipworm

life science Maturity 5-7 Next article →

Shipworms are marine animals belonging to the family Teredinidae. Although they appear to be worms, they are actually bivalve molluscs. This means they are closely related to clams and mussels. They are famous for boring into wood that is submerged in seawater. Because they can destroy wooden piers, docks, and ships, people call them "termites of the sea."

Teredolites
Teredolites

The shipworm uses a specific mechanism to excavate its home. At the anterior end, or the front, of its long body, it has two tiny shells called valves. The animal uses these valves to rasp and grind through wood. As they drill, they create a burrow that is often lined with a calcareous tube. This tube is made of calcium carbonate. To protect itself, the shipworm has two calcareous plates called pallets. These pallets sit at the posterior end, or the back, of the animal. If the shipworm feels alarmed, it withdraws its siphons and uses the pallets to block the tunnel opening.

Digesting wood requires a complex biological process involving symbionts. A symbiont is a living thing that lives in a relationship with another organism. Inside the shipworm gut, there is a sub-organ called the typhlosole. This organ contains bacteria from the *Alteromonas* group. These bacteria digest lignin, which is a tough molecular layer in wood. By breaking down the lignin, the bacteria allow enzymes to reach the cellulose inside. Additionally, a bacterium called *Teredinibacter turnerae* lives in the gills. This bacterium secretes cellulose-digesting enzymes into the gut through an organ called the gland of Deshayes.

Taret Anatomie
Taret Anatomie

Shipworms have unique anatomy due to their slender, cylindrical bodies. An average adult measures less than 10 centimeters in diameter. However, some species can grow to a length of about one meter. Their bodies are naked and superficially vermiform, which means they look worm-like. Their internal organs are specialized for living in tight spaces. For example, their gills are divided into a small anterior half and a large posterior half. The heart-kidney system is also tilted. This brings the kidneys into a dorsal position relative to the heart.

PSM V13 D568 Teredo navalis
PSM V13 D568 Teredo navalis

History shows that humans have long studied these creatures. Carl Linnaeus assigned the name *Teredo* to the most famous genus in 1758. In the 20th century, Ruth Turner of Harvard University became a leading expert. She published a detailed monograph on the Teredinidae in 1966. For centuries, scientists identified huge mollusks by the shells they left behind. Some of these shells were as large as baseball bats, measuring about 30 centimeters in length.

Local speciality tamiloc (9163532353)
Local speciality tamiloc (9163532353)

Shipworms have interesting life cycles and habitat requirements. *Teredo navalis* develops from eggs to larvae in about five weeks. They are hermaphrodites when young, but adults are usually male first and then female. They have a lifespan of one to three years. These animals are cosmopolitan, meaning they are found in many parts of the world. They spread by traveling in wooden-hulled vessels or by floating on driftwood. However, they need a salinity level greater than 0.8% to reproduce. Freshwater is deadly to them, which is why shipworms are rare in the Baltic Sea.

Humans have developed methods to protect structures from shipworm damage. In the late 18th century, people began using copper sheathing. This involved covering the wooden hulls of ships with copper to prevent boring. Today, the study of shipworms has moved into new scientific fields. Researchers are studying the endosymbionts in their gills for bioconversion research. They want to see if these microbes can help create fuel energy.

Teredolites
Teredolites
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File:PSM V13 D568 Teredo navalis.jpg
PSM V13 D568 Teredo navalis.jpg
File:Taret Anatomie.JPG
Taret Anatomie.JPG
File:Teredolites.jpg
Teredolites.jpg
File:Local speciality tamiloc (9163532353).jpg
Local speciality tamiloc (9163532353).jpg
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