ch 30; protostomes

protostomes

triploblastic, have anterior brains and a ventral nervous system

lophotrochozoans

untied by lophhophore and trochophore larva

arrow worms

outgroup to lophotrochozoans

annelids

coelomate segmented worms w nerve ganglia in each segment

polychaetes

segmented, tube feeted worms, some have tentacles

pognophorans

live in tubes of chitin around hydrothermal vents

clitellates

have no divisions of coelom and consists of earthworms and leeches

mollusks

most diverse group of lophotrochozoans- have a foot, mantle, and visceral mass

gastropods

snails, slugs, abalones, nudibranchs and limpets- some have lost their shell and all glide on their foot for movement

bivalves

clams, oysters scallops and mussels; have hinged left/right shells, two siphon system to bring in and filter food and water

cephalopods

squid, octopi, cuttlefish, and nautilus; move via jet propulsion from a modified excurrent siphon and have complex sensory organs and developed eyes

ecdysozoans

shed their hard cuticle to grow over their lifetime

nematodes

unsegmented, do gas exchange through diffusion, model organism

tardigrades

fleshy unjointed legs, can stay dormant while dehydrated for years

arthropods

most abundant and diverse animal clade, have jointed limbs connected w internal muscles to their exoskeleton, segmented bodies allow for specialization

chelicerates

arachnids, trilobites, horseshoe crabs; have a cephalothorax and abdomen and four pairs of legs; hollow fangs that can inject venom (chelicerae)

mandibulates

myriapods, crustaceans and insect; united by mandibles, more specialized clamping jaws

myriapods

millipedes (kind) and centipedes (evil)

crustaceans

dominant marine arthropods, covered by a fused carapace of multiple segments- have a head thorax and abdomen and 5 pairs of appendages

hexapods

six legs; 3 body regions (head w antennae, thorax w 2 pairs of wings, and abdomen), breathe through trachae that open through skin, metamorphosis can be complete or incomplete

neopterans

insects that evolved wings that can fold into their abdomen