Protostomes

major subgroups of protostomes

lophotrochozoa and ecdysozoa

lophotrophozoa

rotifers, flatworms, annelid worms, mollusks

ecdysozoa

nematode worms, tardigrades, onychophora, arthropods

aid in exchange of gases

high surface area to volume ratio

aids in avoiding drying out

have gills in body, waxy layer, desiccation resistant eggs

main morphological traits of lophotrochozoans

lophophore, trochophore, spiral cleavage pattern

lophophore

feeding structure ringing mouth of animal, used in suspension feeding

trochophore

type of larvae with ring of cilia around middle aiding in feeding and swimming

major lineages of liphotrochozoans

rotifers, platyhelminths (flatworms), annelids, mollusca

platyhelminths (flatworms)

lacking coelom and specialized structures for gas exchange, circulation of oxygen and nutrients

platyhelminth phyla

tubellaria, cestoda, trematoda, monogenea

tubellaria

free living, freshwater or marine, have blind digestive track, mouth near middle of body

cestoda

endoparasitic tapeworms that parasitize vertebrates absorbing nutrients across their body wall

trematoda

endoparasitic or ectoparasitic that parasitize vertebrates, annelids, mollusks, arthropods

monogenea

ectoparasites that parasitize specific tissues of usually fish gills or skin

annelids

have coelom, full digestive track, segmented body

annelida groups

polychaeta, oligochaeta, hirudinea

polychaeta

live in marine habitats, highly mobile, large parapodia and chaetae

oligochaeta

deposit feeders in soil, provide several ecosystem services, earthworms

hirudinea

leeches, ectoparasites that suck blood and other fluids, can be predators or scavengers

mollusca

have foot for movement, visceral mass with main internal organs and external gill, mantle that covers visceral mass

mollusca lineages

chitons, bivalves, gastropods, cephalopods

molting

ecdysozoan growth

key lineages of ecdysozoans

nematods, tardigrada, onychophora, arthropoda

nematoda

roundworms, have pseudocoelom, gas exchange across body wall/diffusion, tube within tube body

tardigrada

waterbears, no exoskeleton or jointed limbs, live in water

onycophora

velvet worms, no exoskeleton or jointed limbs, prey on small invertebrates

arthropoda

in aquatic and terrestrial environments, segmented body, exoskeleton of chitin, jointed appendages

major arthropod lineages

myriapods, insects, crustaceans, chelicerates

myriapods

millipedes or centipedes, head, trunk with segments and one or two pairs of legs per segment, no eyes or simple eyes, terrestrial

insects

head, thorax, abdomen, six walking legs, two or four wings, 4 mouthpart structures, two antennae, compound eyes, terrestrial adults

crustaceans

head, thorax, abdomen, carapace, branched appendages, four to six mouthparts, some have mandibles, maxilla, maxillipeds or claws for feeding

chelicerates

horseshoe crabs, sea spiders, 2 tagmata, abdomen, no antennae, eyes, pair of claw like appendages near mouth for feeding or defense, pedipalps, terrestrial or marine

hemimetabolous metamorphosis

incomplete, juveniles look like smaller adults

holometabolous

complete, larvae have different form than adults and can live in different environments, larvae become pupa