-called arthropods -means jointed feet Phylum: Arthropoda -called arthropods -means jointed feet
I. Characteristics A. Have moveable appendages (legs)
B. Have bilateral symmetry (same on both sides when cut in half) C. Have a crust or shell (called crustaceans) 1. called an exoskeleton 2. made of chitin
II. The body of arthropods A. 2 main segments: 1. abdomen 2. cephalothorax- head and chest (covered by the carapace)
B. Legs of arthropods 1. Claws: first pair of legs used in getting food 2. If a crustacean has 5 pairs of legs, it is called a decapod (meaning 10 feet) C. Swimmerets: small, paddle-like appendages
III. Molting A. Definition: A process by which a crustacean grows and sheds its outer covering. B. Happens usually once a year C. The crustacean is vulnerable shortly afterwards because shell is soft at first
IV. Types of crustaceans A. Lobster 1. Basic facts a. Are predators b. Can also be scavengers c. Can release a claw for protection (a new one grows back)
2. Digestion: one way digestive tract (in the mouth, out the anus) 3. Breathing: through gills 4. Circulation: 1 chambered heart have an open circulatory system a. No veins or capillaries b. Blood moves in open spaces
5. Eyes: mounted on moveable stalks 6. Reproduction: a. sexually (sperm and egg) b. Internal: male deposits sperm into female abdomen c. Female carries eggs for almost 1 year d. When larva hatch, become part of plankton population
B. Crabs 1. Mostly eat dead plant and animal matter (some are predators) 2. All life activities are similar to lobster
V. Crustacean Facts A. The Northern Lobster 1. Live along Rocky subtidal zones along Atlantic Coast
B. Spiny Lobster Does not have large claws like most lobsters Live in waters of Gulf of Mexico and California
Spiny Lobster
C. Mole crab Has a smooth, streamlined body for burrowing in sand Has featherlike antennae to catch microorganisms
D. Fiddler Crab Males have one large and 1 small claw (looks like it is playing a fiddle) Females have 2 small claws http://www.fiddlercrab.info/uca_video.html
E. Hermit Crab Does not have an exoskeleton Finds empty shells to live in As it grows, it finds new shells to live in
F. Spider crab Moves so slowly that algae and barnacles grow on them
G. Gulf Shrimp 1. grows up to 17 cm. 2. popular seafood shrimp
H. Mantis shrimp 1. largest, grows up to 25 cm. 2. spears prey with appendages that unfold like a jackknife
I. Cleaner shrimp 1. One of the smallest shrimp 2. rides on fish and eats parasites off skin Cleaner shrimp,
The Banded Coral Shrimp
What do these animals have in common with one another? Whale Shark Adélie Penguin Blue Whale Right Whale
They all depend on these…
VI. More Crustaceans A. Krill (plankton) 1. coldwater organism 2. More than 10 legs
B. Copepods (plankton) 1. Most abundant 2. less than 1/2 cm. long (almost microscopic) 3. Base of the food chain (feed many other organisms)
C. Beach flea 1. Live among moist seaweed along the shore
2. swim and crawl in coastal waters D. Sea roach 1. looks like a pill bug 2. swim and crawl in coastal waters 3. Active at night (like the cockroach) Pill Bug
C. Barnacles
Are sessile crustaceans that use feathery appendages to catch food (called cirri) **Sessile: do not move about freely, stay put Are filter feeders Types: a. Acorn barnacle –live along Atlantic coast live attached to surfaces and rocks
b. Gooseneck barnacle- found along Pacific coast -have long stalks for attachment
Barnacles on whales