Nonchordate Lab

Phylum Arthropoda

triploblastic; coelomates; cephalization present; bilateral symmetry; complete digestive system; true segmentation; protostomes; perform ecdysis

• are subdivided into 4 groups

ecdysis

process of shedding/molting the cuticle, used by Nematoda & Arthropoda

cuticle

a tough coat that covers Ecdysozoans (Nematoda & Arthropoda)

Chelicerata/Chelicerates

2 body segments; have chelicerae not mandibles; no antenna present; horseshoe crabs, spiders, ticks (arachnids)

chelicerae

clawlike feeding appendages on Chelicerates

Myriapoda/Myriapods

many body segments; have mandibles; have antenna; centipedes, millipedes

Crustacea/Cristaceans

2 body segments; have mandibles; have antenna; crabs, barnacles

Insects/Hexapoda

3 body segments; have mandibles; have 1 antennae pair; lady bugs, grasshoppers, lice

Phylum Echinodermata

larvae are bilaterally symmetrical; coelomates; deuterostomes; adults have pentamerous body plan/nonsegmented; endoskeleton of calcareous plates; water vascular system; marine

(ex: sea urchins, sea biscuits, sand dollars, starfish)

water vascular system

network of hydraulic canals that branch into tube feet, present in Echinoderms

tube feet

assist in Echinoderm locomotion and feeding

Phylum Porifera

asymmetrical; filter feeders; cells not differentiated into true tissues; lack true organs; triploblastic

(ex: sponges, Grantia)

hermaphrodites

fiction first as one sex then as the other (most sponges)

Phylum Cnidaria

only diploblastic phylum; radially symmetric; divide into Medusozoa/jellies, Anthozoa/sea anemones; use cnidocytes

cnidocytes

unique cells that function in defense and capture of prey in Cnidarians

nematocysts

specialized organelles within cnidocytes that eject a stinging thread

Phylum Platyhelminthes

triploblastic; acoelomates; tissues arranged into organ systems; bilateral symmetry; have cephalization; have a gastrovascular cavity; they are otherwise known as “flatworms”

(ex: planarians, flukes, tapeworms)

cephalization

concentration of nervous tissue at the anterior end

Phylum Mollusca

coelomates; unsegmented body divided into mantle, visceral mass, and foot; external/internal shell; triploblastic; protostomes; divided into 4 subgroups

Chitons

use radula to eat algae, use foot as suction, protected by 8 dorsal plates

Gastropods

move slowly by rippling motion of foot; eat by radula; protected by spiral shell; snails, slugs

Bivalves

use gills to filter food; move by foot/adductor muscles; have shells; clams, oysters, mussels

Cephalopods

use beak to feed; shoot water out to move; internal/reduced shell

Phylum Annelidia

segmented worms; coelomates; series of fused rings; triploblastic; protostomes; bilateral symmetry

(leeches, worms)

Ecdysozoans

coverered in a tough coat called cuticle and carry out ecdysis

Phylum Nematoda/Nematodes

roundworms; found in body fluids/animal tissue; only psuedocoelomates; cephalization; bilaterally symmetric; protostome; complete digestive tract