Mollusks

invertebrates

animal without a backbone

gills

organs that remove oxygen from water

mantle

thin layer of soft tissue that covers the internal organs and produces the shell

open circulatory system

system in which the blood is not always contained in blood vessels

herbivore

animal that only eats plants

carnivore

animal that only eats other animals

scavenger

an organism that feeds on dead or decaying material

omnivore

animal that eats both plants and animals

radula

flexible ribbon of tiny teeth used to obtain food

gastropod

largest group of mollusks; having one or no shell; includes snails and slugs

bivalve

mollusk having two shells held together by hinges and strong muscles

cephalopod

ocean dwelling mollusk whose foot is adapted to form arms & tentacles around the mouth

closed circulatory system

system in which the blood is always contained in blood vessels

broad foot

organ that gastropods & bivlalves use for crawling, digging, or attaching to a surface

arms

modified foot of a cephalopod; covered with suckers on the underside; used to move, bring food to the mouth, or "taste" surrounding water

tentacles

modified foot of a cephalopod with suckers on the tips; used to grab food during hunting

filter feeder

organisms that feed by straining tiny organisms and plant matter out of the water

cilia

tiny projections on the gills that move muscus coated food from the gills to the palps

palps

organ that moves mucus covered food from the cilia to the mouth

bilateral symmetry

two halves that are mirror images of each other

one way digestive tract

digestive system in which food enters through one opening, passes through the body, and waste exits through another opening

snail

gastropod with one shell and a broad foot

slug

gastropod with no shell and broad foot

shell

hard covering of a mollusks that protects the internal organ

anus

orifice through which food waste exits the body

mantle cavity

space inside the mantle where the internal organs are located

umbo

oldest part of the shell of a bivalve from which the shell grows

ligament

part of a bivalve that opens the shells when the adductor muscle is relaxed

intestine

organ that completes digestion and absorbs nutrients from food

heart

organ that pumps blood

adductor muscles

muscles of a bivalve that keep the shell tightly closed

exhalant siphon

tube through which a bivalve expels water from which it has removed food and oxygen

inhalant siphon

tube through which a bivlave takes in water to filter out food and get oxygen

stomach

organ that breaks down food with digestive juices

mucus

slimy substance created by some gastropods to aid in creeping on surfaces to protect the foot OR sticky substance on gills of a bivalve to capture food as it filters through the gills

larva

immature form of an invertabrate animal that does not look like the adult

oyster

marine bivalve often farmed for its pearl-making ability

pearl

a smooth, rounded bead formed within the shells of certain mollusks in response to an irritant

pearl sac

piece of mantle tissue that surrounds an irritant to form the center of a pearl

nacre

also called mother of pearl; material that makes a pearl oyster's shell as well as forms the pearl

squid

cephalopod with an internal shell and a modified foot that forms 8 arms and 2 tentacles

octopus

cephalopod with no shell and a modified foot that forms 8 arms and no tentacles

nautilus

cephalopod with an external shell and a modified foot that forms many arms

ink sac

organ in a cephalopod that produces ink ejected from the body to confuse and distract predators

gill hearts

pump blood from the body back to the gills to get oxygenated

liver

organ that helps remove toxins from the blood

beak

hard, sharp, tooth-like structures used by cephalopods to crush and kill prey

suckers

structures on the underside of the arms of octopi & squid used for grabbing and pulling

jet propulsion

the means by which squid & octopi propel themselves quickly through the water; movement of the body caused by the forced expulsion of water

camouflage

change of appearance to blend with surroundings to hide from predators

predator

organism that exists by preying on other organisms

prey

an animal hunted or seized for food

mantle collar

structure through which a cephalopod allows water to enter the mantle cavity in preparation for jet propulsion