Happy as a Clam

Happy as a clam is a colloquial expression – a simile to describe a happy person. If a person is said to be ‘as happy as a clam at high water’ it means that they are content and satisfied. 

What is the origin of this expression? The website The Phrase Finder believes that it may have originated in America in 1833 in the book The Harpe’s Head – A Legend of Kentucky – “It never occurred to him to be discontented … He was as happy as a clam.” General Robert E Lee used the phrase too in the 1830s.

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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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Maxima Clam

The Maxima Clam (Tridacna maxima) is a marine (saltwater) bivalve mollusc in the Cardiidae family. It is also called the Small Giant Clam. It is related to the Cockle. 

The Maxima Clam has a thick shell called a mantle. Its shell is actually two equal-sized calcareous valves connected with a flexible adductor muscle. The shell can open and close. Bi-valve means two valves (or two shells). The mantle is bright-blue, green, or brown with distinctive furrows. It has a mouth, a heart, kidneys, a stomach, and a nervous system. 

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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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Bluegreen Giant Clam

The Bluegreen Giant Clam (Tridacna derasa) is a marine (saltwater) reef bi-valve mollusc in the Cardiidae family. It is also called the Southern Giant Clam. It is related to the Cockle.

The Bluegreen Giant Clam is smoother than most clams, because it lacks ridging. It has a thick shell, called a mantle. Its shell is actually two equal-sized calcareous valves connected with a flexible adductor muscle. The shell can open and close. Bi-valve means two valves (or two shells). It has 6-7 rippled edges, called folds or flute. It does not have scutes (scales). The mantle has stripes or spots and is blue and green, with some white patches. It has a mouth, a heart, kidneys, a stomach, and a nervous system.

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Giant Clam

The Giant Clam (Tridacna squamosa) is a marine (saltwater) reef bi-valve mollusc (mollusk).  It is also called the Fluted Giant Clam or the Scaly Clam. It is related to the Cockle.

The Giant Clam has a thick brown, green, or purple-coloured ridged shell, called a mantle. Its shell is actually two equal-sized calcareous valves connected with a flexible adductor muscle. The shell can open and close. Bi-valve means two valves (or two shells). The mantle has 6-7 rippled edges, called folds or flutes. It has scales, called scutes. It has spotted patterns on the mantle. It has a mouth, a heart, kidneys, a stomach, and a nervous system.

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