PROTOSTOMES (LOPHOTROCHOZOA & ECDYSOZOA)

Protostomes

Animals in which the mouth develops before the anus

Lophotrochozoans

Protostomes with lophophores or trochophore larvae

Lophophore

Ring of ciliated tentacles used for feeding

Trochophore larva

Free-swimming larval stage with cilia

Platyhelminthes

Flatworms with simple body systems

Acoelomate

Animal lacking a body cavity

Gastrovascular cavity

Digestive cavity with one opening

Rotifera

Microscopic animals with ciliated crown

Corona

Crown of cilia used for feeding

Annelida

Segmented worms with repeated body units

Segmentation

Body divided into repeating segments

Setae

Small bristles used for movement and defense

Mollusca

Animals with mantle, foot, and radula

Mantle

Tissue that secretes shell

Foot

Muscular structure for movement

Radula

Feeding structure used to scrape food

Ecdysozoans

Protostomes that molt their exoskeleton

Ecdysis

Shedding of outer covering

Nematoda

Roundworms with pseudocoelom

Pseudocoelom

Body cavity not fully lined with mesoderm

Hydrostatic skeleton

Fluid-filled cavity providing support

Tardigrada

Water bears that survive extreme conditions

Arthropoda

Animals with jointed appendages and exoskeleton

Exoskeleton

Hard outer covering made of chitin

Chitin

Structural polysaccharide in exoskeleton

Jointed appendages

Limbs that allow movement

Chelicerates

Arthropods with fangs and four pairs of legs

Myriapods

Arthropods with many legs

Hexapods

Insects with three pairs of legs

Crustaceans

Aquatic arthropods with gills

Metamorphosis

Process of developmental transformation

Complete metamorphosis

Larva → pupa → adult

Incomplete metamorphosis

Young resemble smaller adults

Vector

Organism that transmits disease