BIO101 Unit 8
Animal Kingdom Invertebrates II
Phyla Mollusca, Arthropoda & Echinodermata
Glossary
abdomen
a body segment of many animals which represents the rear or lower portion of the animal. (This segment can contain reproductive structures or defensive structures such as stingers).
appendages
a jointed structure of animals that can be used for walking, swimming, eating, reproducing or sensing their environment.
arachnida
a class of the phylum arthropoda that includes spiders and scorpions.
arthropoda
a phylum that includes animals with jointed appendages and an exoskeleton composed of chitin like insects.
bilateral symmetry
body plan having two complementary halves
bivalves
a class of the phylum mollusca that includes animals with an exoskeleton composed of two shells like clams.
carapace
a hard covering of the cephalothorax of some animals.
carnivore
animals that eat other animals.
caste system
a social system of many animals in which individuals of a colony provide different functions for the benefit of the entire group.
cephalothorax
a portion of an animal that has it’s head an thorax regions fused forming this one segment.
cephalopods
a class of the phylum mollusca that includes carnivores with muscular tentacles that surround their head region like the octopus.
chitin
an organic substance that forms the exoskeleton of the animals of the phylum arthropoda.
chilopoda
a class of the phylum arthropoda that includes centipedes.
copulatory organ
the male or female body structures that function during the act of depositing sperm within the female body.
crustacea
a class of the phylum arthropoda that includes lobster, crabs and shrimp.
dimorphic
a group of animals that have both male and female individuals.
diplopoda
a class of the phylum arthropoda that includes millipedes.
echinodermata
a phylum that includes animals that have a spiny skinned exoskeleton and a water vascular system with tubed feet like a starfish.
exoskeleton
an external skeleton of some animals.
filter feeders
method of obtaining food by sponges and other animals which strain small organic material from the water in a way that deposits the food into the digestive tract.
gastropods
a class of the phylum mollusca that includes herbivores with a flattened muscular foot like a snail.
green gland
a structure found in the cephalothorax of a crustcea which removes organic waste from body fluids.
herbivore
an animal that eats plants only.
invertebrate
refers to animals that lacks a vertebral column (backbone).
malpighian tubules
an excretory structure found in insects that removes nitrogenous waste.
mantle
a membranous muscular structure that covers the visceral mass of a mollusk that may secrete a shell.
metamorphosis
changes in the body form of some organisms as they develop from their larval form to the adult form. (caterpillar to butterfly)
mollusca
an animal phylum that includes clams and other animals with hard cells and soft bodies.
nocturnal
refers to an animal that is best suited to be active at night.
open circulatory system
a type of circulatory system in some animals which is composed of a heart and arteries but no veins.
ovipositor
a reproductive structure found on the abdomen of female insects that is used to lay eggs.
parasites
organisms that live on or in another organism taking food from that host animal.
pincers
pinching claws that some animals like lobsters possess.
radial symmetry
body plan which can be divided into complementary halves by more than one plane
regeneration
a form of asexual reproduction by which pieces that are broken from a parent will develop into a new organism. The parent also will repair itself by this process.
scavenger
an animal that eats dead organic remains of other animals
segmentation
repetition of body parts as divisions along the length of the animal’s body; seen in animals of the phyla annelida, arthropoda, and chordata.
somites
serial segments of main body parts.
spiracles
small openings found on the abdomen of insects that function as respiratory structures.
symmetry
an animal or object which can be divided into complementary halves by a plane.
terrestrial
organisms that live mainly on land.
thorax
the central segment of many animals that usually contains important respiratory and circulatory structures.
tympanum
a sensory structure found on the abdomen of insects that receives sound waves.
visceral mass
the soft body portion of a mollusk that contains the vital internal organs.