1. Crustacea 2 pairs of antennae Nauplius larvae 45,000 spp 6 subclasses –subC Malacostraca – decapods, amphipods, isopods (60%) –subC Brachiopoda – daphnia, brine shrimp, fairy shrimp –subC Ostracoda – ostracods –subC Copepoda – copepods –subC Pentastomida – tongue worms (nose parasites) –subC Cirripedia - barnacles

2. subC Branchiopoda “gill foot” O. Cladocera = Daphnia –Major component of FW plankton –Diel vertical migrations –Parthenogenic, ephippia, cyclomorphic, O. Anostraca= fairy shrimp, brine shrimp –Sexual ephippia

3. subC Ostracoda Look like small clams that actively swim Head encased in bivalve carapace Very common in FW, but also marine and some are terrestrial

4. subC Copepoda Major component of plankton in both marine and FW habitats Single eye “Cyclops” Pair of egg sacs trail behind Parthenogenic Most important herbivores in the ocean About 25% are parasitic

5. subC Pentastomida All tongue worms are internal parasites of the respiratory passages of vertebrates (reptiles mostly) Yet fossil record predates vertebrates! Often have intermediate hosts Ingested by final host and migrate to the respiratory tract Position within Arthropoda (and Crustacea) a recent consensus

6. subC Cirripedia = hairy feet (used for filter feeding) Sedentary, secrete calcareous shell Initially classified as molluscs (have tissues analogous to a mantle, mantle cavity) O. Thoracica = the barnacles Some cirripeds in other orders are parasitic

7. Phylum Nematoda Round worms Formerly classified with other “pseudocoels”, but because the molt cuticle, now associated with Arthropoda in the “Ecdysozoa” (ecdysis = molting) All use same hormone to trigger molting Nematodes are the numerically most abundant multicellular animal on the planet (1M/m 2 common) A few are important parasites of people, crops and livestock

8. Phylum Nematoda Grow between molts by eutely High internal hydrostatic pressure maintained by muscular contraction (which also makes them round) Hydrostatics skeleton used for locomotion

9. Parasitic Nematodes Guinea worm (Dracunculus medinensis) –Infects people in Asia and Africa –Adult female (1mm diam, x 120 cm) forms itchy ulcer where ovaries protrude to release eggs in water –Eggs ingested by copepods (intermediate host) –The caduceus (symbol of the medical profession) represents the stick used to slowly wind the worm out of the ulcer –Carter Center on the verge of eradicating this scourge

10. Parasitic Nematodes Hookworm (Necator spp) –Affects 380 million people in tropical countries –Adults feed on blood in intestine –Eggs pass out in feces, hatch and penetrate skin of host (thus common where no sewage control and no shoes) –Migrate through blood stream to lungs, migrate up trachea and enter esophagus

11. Parasitic Nematodes Pinworm (Enterobius spp) –Live in intestine –Adult female crawls out of the anus at night and deposits eggs around perianal region –Wiggling females produces a tickling, itchy sensation causing scratching and infection of fingers with infective larvae –Host reinfects themselves and others –Common in children

12. Parasitic Nematodes Ascaris –Live in intestines of a variety of vertebrates, including humans (SE US) –Feed on fluid of gut contents –Reaches lengths of 50 cm –Can cause malnutrition and intestinal blockage –Eggs remain viable for 20 years –Spp that infects human closely related to spp that infects pigs (recently diverged when human and pigs no longer lived together)

13. Parasitic Nematodes Filariods (filariasis) –Slender (40-90mm x 0.1-0.2mm) –Inhabit lymph system –Infective larvae migrate to surface skin at night –Mosquitoes are vector to spread infection –Adults cause lymph blockage (elephantiasis) –Heart worm in dogs is one of these

14. Deuterostomes Everything from Platyhelminthes to Ecdyosozoa are Protostomes (first mouth) Deuterostomes have “second mouth” embryological development Echinodermata Hemichordata Cephalochordata

15. Phylum Echinodermata = spiny skin Radial symmetry (pentaradial) Hydrostatic skeleton for locomotion and internal transport Coelomates Triploblastic Complete digestive tract

16. Class Crinoidea