External Anatomy of the Clam copyright cmassengale 1

Bivalve Shell • Umbo is the raised, oldest part of the shell and is

Bivalve Shell • Shell show regular spacing of external growth rings on shells and

Bivalve Shell • Bivalves have an incurrent and excurrent siphon to bring in water

Bivalve Shell • The hinge ligament holds the two halves of the shell together

Internal Anatomy copyright cmassengale 7

Scissor tips or a screwdriver & can be used to open the shell copyright

Adductor Muscles Strong adductor muscles help open & close the valves and must be

Inside Shell Lining • The inside of the shell is pearly and smooth to

Teeth located on the dorsal edge of the shell lock to keep shells from

The mantle makes a Ca. CO 3 (limestone) shell copyright cmassengale 14

Mantle cavity Gills hang outside visceral mass (body) in the mantle cavity & remove

Water Flow • Incurrent siphons aid in bringing in water with food and oxygen

VISCERAL MASS - contains respiratory, digestive, & reproductive systems copyright cmassengale 20

HEART & PERICARDIAL CAVITY copyright cmassengale 21

Nervous System • Consists of 3 pairs of ganglia (brain) • Has 2 pairs

Released into Mantle Cavity to be removed by excurrent Siphon: • Nitrogen waste from

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External Anatomy of the Clam copyright cmassengale 1

Bivalve Shell • Umbo is the raised, oldest part of the shell and is used to find surfaces Dorsal UMBO Posterior Anterior Ventral copyright cmassengale 2

Bivalve Shell • Shell show regular spacing of external growth rings on shells and their progressive crowding as the animals grow older Growth Rings copyright cmassengale 3

Bivalve Shell • Bivalves have an incurrent and excurrent siphon to bring in water containing food & O 2 and for excess water & wastes to leave Siphons copyright cmassengale 4

Bivalve Shell • The hinge ligament holds the two halves of the shell together copyright cmassengale 6

Internal Anatomy copyright cmassengale 7

Scissor tips or a screwdriver & can be used to open the shell copyright cmassengale 8

Adductor Muscles Strong adductor muscles help open & close the valves and must be cut to examine the interior of the clam copyright cmassengale 9

Inside Shell Lining • The inside of the shell is pearly and smooth to protect the body • Oysters coat irritants with a substance called “mother of pearl” copyright cmassengale 11

Teeth located on the dorsal edge of the shell lock to keep shells from sliding copyright cmassengale 13

The mantle makes a Ca. CO 3 (limestone) shell copyright cmassengale 14

Mantle cavity Gills hang outside visceral mass (body) in the mantle cavity & remove O 2 as H 2 O flows over them copyright cmassengale 15

Water Flow • Incurrent siphons aid in bringing in water with food and oxygen • Cilia direct water into the gills, while labial palps direct water into the mouth move food toward the mouth Cilia on the gills pulls in water copyright cmassengale 19

VISCERAL MASS - contains respiratory, digestive, & reproductive systems copyright cmassengale 20

HEART & PERICARDIAL CAVITY copyright cmassengale 21

Nervous System • Consists of 3 pairs of ganglia (brain) • Has 2 pairs of nerve cords extending from this copyright cmassengale 22

Released into Mantle Cavity to be removed by excurrent Siphon: • Nitrogen waste from kidney • Digestive waste from anus • Sperm or egg (if external fertilization) • Larva (if internal fertilization) copyright cmassengale 23