TAXONOMY SHEET MIDTERM 2 I. Phylum Mollusca A. general characteristics 1. eucoelomate 2. bilateral symmetry 3. open or closed (in cephalopods) circulatory system 4. ctenidial gills 5. huge, diverse group - probably 3rd largest phylum B. Class Solenogastres and Caudofoveata 1. worm-like 2. shell-less C. Class Scaphopoda 1. tusk shells 2. deposit feeders D. Class Polyplacophora 1. chitons 2. shell - 8 plates (valves) 3. serially repetitious gills 4. open circulatory E. Class Gastropoda 1. subclass Prosobranchia a) marine snails b) gills in front (torsion) 2. subclass Opisthobranchia a) sea slugs b) gills in back (detorsion) 3. subclass Pulmonata a) lung or gill b) terrestrial or freshwater snails and slugs F. Class Bivalvia 1. two halves to shell 2. suspension feeders 3. 3 chambered heart (open circulatory) 4. very specialized for filter feeding G. Class Cephalopoda 1. squid, octopus, cuttlefish 2. closed circulatory 3. little or no shell (except chambered nautilus) a) if shell is present, mainly used for buoyancy 4. subclass Nautiloidea 5. subclass Ammonoidea 6. subclass Coleoidea II. Phylum Annelida A. general characteristics 1. closed circulatory 2. eucoelomate 3. gills or epithelial gas exchange 4. setae / chaetae - chitinous bristles 5. proteinaceous cuticle B. Class Polychaeta 1. lots of setae (chaetae) 2. parapodia 3. gills or parapodia used for gas exchange 4. very diverse (10,000+ species) 5. strong cephalization (prostomium, peristomium, eversible pharynx, jaws) CLITELLATA (oligochaetes, Hirudinea) C. Class Oligachaeta (paraphyletic) 1. earthworms and others. 2. mostly terrestrial, some aquatic 3. no parapodia 4. few setae (chaetae) 5. deposit feeders 6. epithelial gas exchange 7. monoecious D. Class Hirudinea 1. leeches - often ectoparasites 2. reduced or lost septa 3. no setae or parapodia 4. anterior and posterior suckers 5. mostly freshwater, some marine, some terrestrial III. Phylum Nemertea A. general characteristics 1. rhynchocoel - eversible proboscis often with venomous stylet 2. paired eyespots 3. derived “circulatory” system IV. Phylum Brachiopoda A. general characteristics 1. bivalve 2. attached by pedicel 3. lophophore used for feeding and gas exchange V. Phylum Entoprocta A. general characteristics 1. pseudocoelomate 2. ciliary feeding with tentacles 3. often protandrous hermaphrodites VI. Phylum Ectoprocta A. general characteristics 1. eucoelomate 2. ciliary feeding with lophophore VII.Phylum Cycliophora A. general characteristics 1. acoleomate 2. sexual and asexual stages ECDYSOZOA VIII.Phylum Nemata A. general characteristics 1. some parasitic, but many free-living 2. probably second biggest phylum (probably at least 500,000 species) 3. eutely 4. collagenous cuticle 5. pseudocoelomate 6. only longitudinal muscles IX. Phylum Nematomorpha A. general characteristics 1. some parasitic, but many free-living 2. probably second biggest phylum (probably at least 500,000 species) X. Phylum Priapulida A. general characteristics 1. caudal appendages 2. chitinous cuticle 3. special urogenital organs with solenocytes XI. Phylum Kinorhyncha A. general characteristics 1. scalids 2. pseudocoelomate XII.Phylum Loricifera A. general characteristics 1. deep ocean sediments 2. sessile 3. anaerobic 4. higgins larva 5. lorica covering abdomen XIII.Phylum Tardigrada A. general characteristics 1. “water bears” 2. cryptobiosis 3. somewhat similar to arthropods 4. fluid feeders 5. open circulatory 6. eucoelomate XIV.Phylum Onychophora A. general characteristics 1. “velvet worms” 2. somewhat similar to arthropods 3. open circulatory 4. eucoelomate ***** END OF GROUPS FOR MIDTERM 2 *****.