What are the similarities and differences between the Giant Clam and the Maxima Clam?

What are the similarities and differences between the Giant Clam (Tridacna squamosa) and the Maxima Clam (Tridacna maxima)?

The Giant Clam and the Maxima Clam are both marine (saltwater), bivalve molluscs in the Cardiidae family. Bivalve means two valves (or two shells). They both prefer to live on the bottom of the ocean in shallow coral reefs.

The Giant Clam and the Maxima Clam both have a thick, ridged calcium carbonate shell, called a mantle. Their shells, which can open and close, have two equal-sized calcareous valves connected with a flexible adductor muscle. 

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Soft-Shell Clam

The Soft-Shell Clam (Mya arenaria) is a marine (saltwater) bivalve mollusc in the Myidae family. It is also known as the Sand Gaper.

The Soft-Shell Clam has an elongated calcium carbonate shell that is thin and fragile (beach clams have thicker shells). The shell is called a mantle. It has two valves (two halves), joined together by a ligament hinge with two adductor muscles that enable it to open and close. It has paired siphons which helps it to breathe when it is under the mud. It has light-sensitive cells that can detect light and motion.

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What is the difference between a clam, a cockle, a mussel, and a scallop?

What is the difference between a clam, a cockle, a mussel, and a scallop?

The clam, cockle, mussel, scallop, and even the oyster, are all marine bivalve molluscs. Bivalve means two valves.

They all have a shell structure, called a mantle, with two valves (two halves) and a ligament hinge with two adductor muscles that enable them to open and close.

All bivalves have light-sensitive cells that can detect light and motion, even though most do not have eyes. Giant clams have simple eyes on the edge of the mantle. Scallops have more complex eyes on the edge of the mantle – they have 10-100 eyes that each have a lens, a two-layered retina, and a concave mirror.

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Cockle

The Cockle (Cerastoderma edule) is a small marine (saltwater) bivalve mollusc. It is also called a Clam, but it is not a true clam (a true clam does not live near the bottom of the ocean).

The Cockle has a white-creamy-yellowish-brown oval-shaped shell, called a mantle, with bilateral symmetry – its two valves are the same – connected by two hinge-type adductor muscles that enable it to open and close. The mantle has many slight ridges, called ribs. It has a foot which helps it to bury itself in the ocean floor.

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