Question

'Ship-worm' is a destructive mollusc for wood, its generic name is
(a) Teredo
(b) Lamellidens
(c) Aphrodite
(d) Mytilus

Answer 1

Hint: The shipworms are marine bivalve molluscs. They belong to the family Teredinidae. They are notorious for boring into the wood that is immersed in seawater. They are also called termites of the sea.

Complete answer:
Teredo navalis is commonly known as the naval shipworm. They are the species of saltwater clam. They are marine organisms that belong to the group of bivalve molluscs, in the family Teredinidae. This organism is called a shipworm because it resembles a worm in appearance. They have long and soft elongated bodies.

The body is cylindrical, slender, naked, and worm-shaped. In spite of their slender, worm-like forms, shipworms possess the characteristic morphology of bivalves. There is a small shell of two valves at the anterior end. This shell is modified and specialized to bore through wood. The two siphons are very long and protrude from the posterior end of the animal. If the animal is alarmed, it withdraws the siphons and the pallets protectively block the opening of the tunnel.

Additional Information:
- Pallets are the organs that the animal uses for boring its tunnel, they generally are located at the tunnel’s end.
- They are borne on the slightly thickened, muscular anterior end of the cylindrical body and they are roughly triangular in shape.
- They have a concave shape on their interior surfaces. The outer surfaces are convex and in most species are deeply sculpted into sharp grinding surfaces with which the animals bore their way through the wood.
So, the correct answer is '(a) Teredo'.

Note:
- The valves of shipworms are separated and the aperture of the mantle lies between them.
- The shipworm lives in waters with oceanic salinity. It is rare in the brackish Baltic Sea, where wooden shipwrecks are preserved for much longer than in the oceans.
- In several shipworm species, dense communities of intracellular bacterial endosymbionts have been found within specialized cells of the gills. These bacteria are believed to be contributing to the digestion of wood.