Test 7 Checklist
•
Mollusks
– Characteristics
• Mantle Sac-like structure that contains the internal organs and secretes the
shell
•
Radula Muscular, tongue-like organ that is covered in various types of toothlike structures for feeding
• Muscular foot Muscular structure used for movement, defense, or burrowing
• Symmetry Mollusks have bilateral symmetry
– Gastropods includes snails, whelks, slugs
• Feeding Grazers or predators
• Defense Some have shell, some are poisonous, some use nematocysts
stolen from jellyfish they have eaten
• Structure Have a single shell or no shell, have a radula,
– Bivalves includes clams, oysters, scallops
• Feeding Filter feeders
• Defense Shells for protection, Use muscular foot to burrow under seafloor or
push away from predators
• Structure Two shells, no distinct head
– Cephalopods includes squid, cuttlefish, octopus
• Feeding predators, use tentacles to capture prey
• Defense ink, jet propulsion
• Structure foot is modified into multiple tentacles, cuttlefish have hard shell,
squid has lightweight pen, and octopus has no shell. Octopus is highly
intelligent.
•
Echinoderms
– Characteristics
• Water vascular system uses water pressure to power the tube feet
• Tube feet part of the watervascular system, used to walk on the
seafloor
•
5 part body plan most body parts in multiples of 5, including sea star arms
and urchin teeth (urchin mouth parts called “aristotle’s lantern”)
• Symmetry Echinoderms exhibit radial symmetry
• Support structure endoskeleton made of calcium carbonate
– Crinoidea
• Examples sea lilies, sea feathers
• Structure arms that extend into the water with spines for suspension
feeding
•
Feeding Suspension feeders
•
• Movement Sessile
– Asteroidea
• Examples Sea stars
• Structure Central disc with five wide arms
• Feeding Predators
• Movement Walk using tube feet
– Ophiuroidea
• Examples Brittle Stars
• Structure Central disc with long, thin arms covered in spines
• Feeding Suspension feeders
• Movement move using arms
• Defense Break off arms to distract predators, then regenerate them
– Echinoidea
• Examples Urchins, Sand dollars
• Structure No arms, body contained inside a “test”
• Feeding Deposit feeders or grazers (herbivores)
• Movement Use tube feet to walk along seafloor
– Holothuroidea
• Examples Sea Cucumber
• Structure Elongated body
• Feeding Deposit feeders
• Movement Use tube feet to walk along sea floor
Arthropods
– Characteristics
• Covering Lightweight, protective exoskeleton made of chitin
• Appendages Jointed appendages
• Symmetry Bilateral Symmetry
– Barnacles
• Feeding Suspension feeders
• Appendages feather-like appendages used for catching food
– Copepods
• Importance Serve as important link between plankton and larger fish in the
food chain
– Decapods
• Appendages 10 legs
• Feeding predators, scavengers
• Chelipeds appendages modified into pincers
– Krill
• Importance Serve as important link between plankton and larger fish in the
food chain
•
Lifestyle live in large “swarms”