Download Soft-Bodied Animals

I. Soft-Bodied Animals
Mollusks
o Mollusks like snails, oysters, clams and
mussels posses a shell that protects the
soft bodied animal inside
o NOT all mollusks live in shells
o More species of mollusks in the ocean
than any other group
o Mollusks occupy ALL marine
environments
Types of Mollusks
Bivalves: (clams, mussels, oysters)
 2 shells
 Shells open & close by a short,
tough muscle
http://www.youtube.com/watch?v=Qp1nrhJAX3I
 filter feeders – feed through its
siphon tube which protrudes
through the gap in it’s shell
http://www.oldearth.org/curriculum/history/Bivalve_siphon.jpg
Gastropods: (snails)
 possess a single shell
 moves by using its muscular foot
 food ingested through its mouth and
taken in by a grasping tongue called
a radula
http://barnegatshellfish.org/images/snails/_radula_01.PNG
http://bogleech.com/sitebuilder/images/gastro-radula-600x168.jpg
http://www.youtube.com/watch?v=zcBmMPJrrKk
Cephalopods: (octopus & squid)
 swimming mollusks
 swim by jet propulsion
 capture prey with their tentacles
(octopus has 8 & squid has 10)
 suction discs are used for grasping
& holding prey
 use camouflage to hide
http://www.youtube.com/watch?v=0b4tmbE5jj4
http://www.youtube.com/watch?v=yefIGm16mKg
http://www.youtube.com/watch?v=1VjxvrXGEHk
Other cephalopods include:
Nautilus –
 inhabits deep waters in
South Pacific
 spiral shaped shell divided
into compartments
http://www.youtube.com/watch?v=hcyzr3zJol4
http://www.youtube.com/watch?v=Ysw3iM3ENQA
Cuttlefish –
 bottom dweller
 feeds in invertebrates in the
sand
http://www.youtube.com/watch?v=WqMNjUp6UeA
http://www.youtube.com/watch?v=__XA6B41SQQ
II. Animals with Armor
http://www.youtube.com/watch?v=-opRt_y0WzM
Arthropods:
o chitinous exoskeletons
o jointed appendages
o also called crustaceans
Crustaceans: (Insects of the Sea)
 crabs, lobsters and shrimp
considered the largest – DECAPODS
 shed their outer skin – Molting
 blood is blue, due to the presence of
a copper based pigment called
hemocyanin (*used in testing
pharmaceutical drug purity)
o Small Crustaceans –
(COPEPODS)
 Krill
 Scud
o Other Marine Arthropods
include:
 Fiddler Crab
 Hermit Crab
 Horseshoe Crab (least
evolved)
III. Spiny Skinned Animals
Echinoderms:
o Invertebrates that possess a spiny skin
Types of Echinoderms:
 Sea Stars



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Brittle Stars
Sea Urchins
Sand Dollars
Sea Cucumbers
Adaptations of the Sea Star:
- possesses five (5) arms
- radial symmetry
- can grow back lost appendage
(regeneration)
- numerous tube feet (suction)
- feed on bivalves
- responds to light and dark
(eyespots)
- inner system connects to the
outside through the madreporite,
a plate on the upper surface