Thursday, July 26, 2007

Snails and clams of the mangroves

Telescopium snail (Telescopium telescopium) Family Potamididae

It is also called 'Rodong' or 'Berongan' in Malay. 8-15cm. It can stay out of water for long periods of time. It eats detritus and algae, using its highly extendable proboscis to gather edible bits from the mud surface at low tide. It is eaten in some places and is said to be delicious when steamed and eaten with chilli.

Belongkeng snails (Family Ellobidae)

Ellobium sp. on the left is usually found on the ground.
Pythia sp. on the right is sometimes seen on leaves of mangrove trees.
These snails are sometimes seen on leaves and trunks of mangrove trees or on the mud in the back mangroves. They are sometimes also called Mangrove helmet shell snails. Empty shells of dead snails are sometimes also washed up on shores near mangroves.

1-5cm. Shells thick. They breathe air (instead of through gills like most other marine snails) and all lack an operculum to seal the shell opening. They graze on algae growing on mangrove trees and debris.

Mangrove jingle clam (Enigmonia aenigmatica) Family Anomiidae

Like shiny scales, these bivalves are common seen on leaves, trunks and roots of mangrove trees. They usually settle at a height between the high spring and high neap tide.

To about 3cm. The two-part shell is thin and lustrous. Usually oval, sometimes irregular. Colours range from beige, purplish to blackish.

One valve is stuck to a hard surface (leaves, tree trunk, roots) and this valve is usually flat. The other valve is usually slightly conical in shape. The valve that is stuck to the hard surface has a notch or hole in it. The animal secretes byssus threads through the hole to stick to the hard surface. A young animal is more mobile and can move around by using its extendible foot. A young animal is relatively broader than a more mature animal.

No comments: