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CHARACTERISTICS OF PHYLUM MOLUSCA

-Triploblastic/three body layers
-Bilaterally symmetrical/non-metamerically segmented coelomates
-The moluscan body consists of three parts; the head, foot and visceral mass
-The head is well defined and bears, two tentacles and two eyes
-The foot is ventral, muscular and flat
-The visceral mass is covered by the mantle, a fold of skin
-The mantle cavity contains: two glands, the hypobranchial gland, the anus, the kidney openings and the osphadium-a chemoreceptor
-The coelom is reduced
-The perivisceral cavity contains blood and is therefore not a coelom but a haemocoel
-The blood system is open
The heart consists of two auricles and one ventricle
-Excretion is by two-tubular nephridia
-Nervous system is circum-pharyngestring frequently concentrated into the cerebral and pleural /ganglia
-Occur in the sea, freshwater and land
-E.g snails, clams, squids and octopuses

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