Clams- Powerpoint

• Clams come in many
colors, including shades of
brown, red-brown, yellow
and cream
• They have shells
consisting of two halves
• The halves are connected
at the top
• The abductor muscles on
each side hold the shell
• They have a foot that is
used to dig into the sand
• They have a pair of long
siphons that extrude from
the clams' mantle
• They inhabit the
subtidal regions of
bays and estuaries to
about 15 meters in
• They are generally
found in mud flats
and firm bottom areas
consisting of sand or
shell fragments
• They can live in
Home sweet
• Clams are filter feeders
that feed on plankton
• Water and food particles
are drawn in through one
siphon to the gills
• Tiny, hair-like cilia move
the water and the food is
caught in the mucus on
the gills
• The food-mucus mixture
is transported along a
groove to the palps that
push it into the clam’s
• The second siphon
carries the water away
• They usually require both
males and females to
• Their eggs and sperm are
released into the water
and then fertilization
takes place
• The eggs hatch into
veligers and they live
among and eat other
• The veligers settle on
rocks, wood, or the ocean
bottom and start to grow
their valves
• Most clams stay in the
same place for much of
their lives but some are
able to move around
• Burrowers move up and
down through mud and
sand by extending their
• Then they expand the tip of
their foot to anchor
themselves and pull their
shelled bodies up or down
in the burrow
• Others "swim" through the
water by clapping their
valves together
• The largest known bivalve
was a Giant Clam which
weighed 734 pounds and
was four feet in length
• The shells the Giant Clams
were used as children's bath
tubs and for baptismal fonts
in many churches
• It was once thought that the
Giant Clam could trap a
diver underwater by closing
suddenly on his or her foot,
but this could only happen
to a very slow or very
careless diver
• Many animals eat clams,
including eels, sea stars,
whelks, and people