BIOL 3454 1nd Edition Final Exam Study Guide Lectures: 27-30 Lecture 11/19o Class Crinoidea ~ 625 species  Sea lilies, feather stars  Flower shaped body at tip of stalk rare among echinoderms in that they are rare among echinoderms in that they are attached much of their life  Some deep water most shallow water around reefs Form and function - Disc called a calyx with leathery skin called tegmen with calcareous plates- Calyx and arms together called a crown attached to a long jointed stalk in sessile forms - Oral surface with a mouth to short esophagus to long intestine with folds called diverticula to an anus which may be on a raised cone - Ambulacral grooves are open ciliated and carry food to mouth - Water vascular system functions entirely on coelomic fluid - NS has an oral ring and a radial nerve for each arm - Separate sexes - Gonads masses of cells in arms - Larvae = dolioloarium - Phylum Hemichordatao Roots Greek hemi (half)/chorda(string or chord)o Used to be a subphylum of the chordates o Have a buccal diverticulum that functions for support called stomochordo Bottom dwellers live in secreted tubed in marine sediments o Class Enteropneusta Acorn worms  Live in burrows in sand and mud Mucus covered body with 3 regions (proboscis, short collar and a long trunk) Probosicis – feeds through ciliated grooves, excavates burrows has small coelomic sac called a protocoel that leads to buccla dicerticulum  Gill pores on each side of trunk behind collar for reparation lead to U-shaped gill slits  Exchange across epithelium  Middorsal blood vessel carries colorless blood enters a network of sinuses calledglomerulus has an excretory function  Dorsal nerve chord similar to chordates rest of NS relatively simple similar to cnidarians and echinoderms Separate sexes  One species asexual reproduction  Fertilization external  Larval = tornaria stage in someo Class Pterobrachia  Similar to enteropneusta but some have structural differences for more sedentary lifestyle  Small live in collagenous tubes Extend crown tentacles from tubes for filter feeding retractable  One pair of gill slits Monoecious and dioecious species  Few can reproduce asexually by budding  Some colonial Lecture 28Lecture 11/21I. Chaetognaths, Echinoderms, HermichordatesII. Mixed characteristics a. Not all taxa are protostome or deuterostome features b. Chateognaths mixed III. Chinoderms have a strange body plan a. Bilateral ancestor and radial as adults b. Coelom modified into a water vascular system for movement c. Free moving but radialIV. Phylum Chaetognathaa. Arrow wormsb. Roots Greek: chaite = long flowing hair/gnathos = jawc. All marine d. Swim to surface at night and descend during the daye. Predatoryf. Form and function i. Unsegmented ii. Body plan: head, trunk and postanal tail iii. Vestibule – depression beneath the headiv. Dorsally located eyesv. Only invertebrates with a many layer epidermisvi. Highly mobile and nearly transparent can have significant ecological impactvii. Complete digestive system and well developed coelom viii. U-shaped ciliary loop over neck and from back of head (mechanoreceptive or chemosensory) ix. No respiratory or excretory systems x. Hermaphroditic (self or reciprocal cross fertilization)xi. Deuterostomes but share characteristics with both groups of phylaV. Phylum Xenoturbellidaa. Hard to place taxonomyb. Deuterostomesc. Single genus with 2 species d. Live in N sea mud e. Feed on bivalves and bivalve eggsf. Sexual reproduction with no structured gonadsVI. Phylum Echinodermataa. Water vascular system of coelomic origin that doubles as part of respiratory system b. Unsegemented with pentraradial symmetry c. Triploblastic and coelom extensive d. Endoskeleton of dermal calcareous ossicles e. Digestive system usually complete axial or coiled f. Bo brain but extensive nerve ring g. Regeneration prominent h. Asexual reproduction by fragmentation i. Separate sexes, free swimming, bilateral larval stages j. Excretory organs absent k. Blood vascular system very reduced l. Circulation by peritoneal ciliam. Fossil record to Cambriann. Bilateral ancestor but evolved radiality (slow and sessile)o. Most have no ability to osmoregulate p. Virtually all bottom dwellers a few pelagicq. Important to knowledge of evolution and development r. Class Asteroidea i. Starfish ii. ~1500 species iii. Predatory iv. Central discs with tapering armsv. Covered with ciliatd pigemented epidermisvi. Mouth that is surrounded by a soft membrane with a canal running from the mouth to the end of each arm vii. Form and function 1. Aboral surface usually rough and spiny 2. Bases around spines have pincer like pedicellariae3. Papulae – soft delicate gill structures 4. Madreporite – tiny pore on the aboral side leading to the water cascular system 5. Endoskeleton made of small calcareous plates called ossicles bound together with connective tissue 6. Collagen is called catch collagen and under neural control and can change from a liquid to solid state 7. Ossicles have a meshwork between them called stereom unique to echinoderms viii. Water vascular system 1. Primary functions – locomotion and food gathering 2. Operates hydraulically3. Madreporite to stone canal to ring canal to several radial canals to manylateral canals to tube feet with end in an external sucker ix. Digestive system 1. Mouth on oral side leads to a short esophagus to a large stomach in central disc lower part of stomach can be everted during feeding 2. Upper pyloric part of stomach is smaller and connects to pyloric ceca in each arm 3. Short intestine leads to small intestinal ceca anus inconspicuous may be absent 4. Like to eat other echinoderms and molluscs and bivalves 5. Few feed on plankton x. Nervous system made of 3 units 1. Oral or ectoneural – nerve ring around mouth and a redaila nerve in each arm 2. Deep or hyponeural – lies aboral to ectoneural system ring around anus and radial nerves along roof of each ray 3. Epidermal nerve plexus or nerve net – connects the two systems along with bodywall 4. Sense organs are not well developed 5. Ocellus at end of each arm xi. Reproductive system 1. Separate sexes2. Fertilization external (eggs and sperm shed into water)3. Can regenerate lost parts 4. Many require lest part of central discs to regenerate 5. Larvae = bipinarria6. Then brachiolaria as they start to mature xii. Sea daisies 1. Highly modified