Review Outline for Exam Two, Spring 2008 Along with this outline study your Lecture Notes, Higher Invert ID Lab (a must, returned after spring break in lecture), and Lecture Quizes (3 and 5) (#3 was over chitons and snails, and #4 was over bivalves and cephalopods) I. Bryozoa A. Basic body form 1. u-shaped lophophore used for filter feeding has mouth in middle 2. u-shaped digestive track with anus on outside of lophophore 3. tiny (pin head sized) body in protective covering (usually a box or tube) of calcium or chitin 4. colonial from cloning within days, cementing boxes or tubes together a. encrusting forms grow along substrate (shell, rock, seaweed) b. arborescent forms grow upward like branches B. Feeding - all are filter feeders with lophophore C. Reproduction 1. most hermaphroditic 2. sperm broadcast spawned 3. eggs broadcast spawned -or- brooded 4. zygote develops to morula then into planktonic cyphonautes larvae (hat-like with cilia on edge) 5. cyphonautes larvae planktonic - sinks and swims 6. cyphonautes larva settles when competent i. forms lophophore and secrets original box or tube ii. clones to form other members of colony who cement their box or tube together to form encrusting or arborescent colonies (a clone) - clones are formed quickly after settlement so individual bryozoa are rarely seen, only colonies D. Variations - one rare form has jelly-like protective covering instead of hard material, one species looks like coral E. Poisoning - none Lesson 38 diagrams (bryozoa only) II. Phylum Mollusca (chitons, snails, slugs, bivalves, octopus, squid) A. General characteristics (three body parts - all soft and non segmented) 1. Head with mouth and radula 2. Foot modified for crawling, digging or secreting attachment threads 3. Body mass with a mantle (if shell is present it is secreted by mantle) B. Four major classes 1. Class Polyplacophora (= chitons) a. Basic Body form i. 8 shell plates that may be covered in part by the mantle (mantle seen surrounding shells from top = girdle) ii. Paired gills in mantle cavity along both sides (usually numerous pairs) iii. Crawl with snail-like foot iv. Respiratory currents thru mantle cavity by head, down each side and out by anus at end created by cilia in mantle cavity (also for sanitation) b. Feeding - Herbivores, using radula to scrape algae (simple head with mouth) c. Reproduction -Separate sexed -Broadcast spawn - fertilization is in plankton -Planktonic trochophore larvae develops from zygote -Sink, swim -Settle -Metamorphose to mini adult with 8 separate shell plates d. Variations - one species covers its 8 shell plates completely with mantle - one species is partly carnivorous e. Poisoning - none Lesson 107 diagrams 2. Class Gastropoda (= snails, slugs) a. Snails: i. Basic Body Form -Shelled forms have undergone torsion (shells often with holes for the sanitation problems that torsion brings) -Basic shell parts: apex (top), protoconch (first whorl), body whorl, spire, sutures, aperture (may have siphonal canal or be entire), operculum (each species has own type - calcium or chitin) -Growth of shell by mantle (thickening shell and adding new shell at aperture) -Basic soft parts of shelled gastropod: head (with mouth, pair of eyes, pair of oral tentacles, radula), crawling foot, body mass covered with mantle (may form siphon) -Crawl with snail-like foot -Gills in mantle cavity - water circulated by cilia in mantle cavity in over head, past gills, past anus and out (taking fecal material) (some use siphon to draw water in to clean gills) ii. Feeding -Some are herbivores using the radula to scrape algae -Some are carnivores using the radula to drill a hole (funnel shaped) into the prey and scoop out the prey's body -Some are omnivores, some are even filter feeders. iii. Reproduction - most separate sexed - mate, internal fertilization - zygotes are laid on solid surface with covering (leathery, mucus, benthic) - veliger planktonic larvae hatch (have one whorl of shell) - sink-swim - settle when competent (possibly to 'cue') - metamorphose to mini adult (protoconch is first whorl of coiled shell, add to it) iv. Variations -Limpets (cap shaped shell, no whorls, no operculum) (regular limpets, keyhole limpets - know differences from lab) -Abalone (no operculum, broadcast spawn) -Cones (special radula may be poisonous to man, but not in Calif.) v. Poisoning - Conus Lesson 31, 79 diagrams b. Slugs (gastropods without a shell) i. Basic Body Form, many types (torsion and detorsion to adult) but most marine slugs are sea hares, nudibranchs, or of the carnivorous Navanax variety - Sea Hares bring skin flaps up on top of body to cover gill and often have defensive ink, they have rhinophores - Carnivorous Navanax variety Slug eater Follows slime trail of other slugs - Nudibranchs (have many forms, two common) - most common worldwide Aeolid nudibranchs Rhinophores Cerata (with extension of gut) (no true gills) Most feed on cnidarians, deposit nematocysts in tips of cerata Dorid nudibranchs Rhinophores Circlet of gills around anus in back Most feed on sponges ii. Feeding - most carnivorous except sea hares that are herbivores iii. Reproduction - slugs are hermaphroditic - mate (cross fertilization) - lay eggs in jelly-like masses - have development of veliger with torsion - sink swim - settle when competent (possibly to cue) - metamorphose to mini adult (detorsion) - adults have digestive tract with mouth at one end, anus at other end (in development they go thru torsion and then in matamorphosis they go through detorsion to adult form) iv. Variations - many are beautiful with a variety of shapes and colors v. Poisoning - care should be taken when handling aeolid forms in areas with poisonous cnidarians Lesson 32, 100 diagrams 3. Class Bivalvia a. Basic Body Form - two shells (valves): i. Hinged at umbo (oldest) - Hinge ligament keeps shells gaped (open), attached inside or outside - Hinge teeth keep shells from slipping side to side ii. Adductor muscles keep shells closed - two equal ones in clams - two of unequal size in mussels - one in scallops and oysters (this is what we eat with scallops) iii. Body covered with right and left mantle - pearls formed here - water current in mantle cavity brings in plankton (caused by cilia in mantle cavity) in a one way flow (in by bottom, out closest to umbo) - mantle may be grown together and elongated to make two siphons that are separate or fused iv. Foot may be reduced or used for digging in sand or mud, or to secrete byssal threads in mussels, or for leaping v. Adaptations of mantle and foot for different modes of living - free living (juvenile rock scallops, file shells) have a reduced foot but can 'swim' - digging (Pismo clams, geoducks) - foot adapted to 'dig' - attached (mussels using specialized foot making byssal threads, adult rock scallops have specialized mantle that attaches edge of shell to solid substrate) - boring into rock, wood, or shell * rock boring clams use mechanical abrasion of soft rock, silt tubes develop * shipworms use sharp shells to bore wood, line burrows with shell * date mussels use chemicals to dissolve calcium shells (abalone lab) b. Feeding - Plankton gathered on mucus on gills found in mantle cavity (filter feeders) and moved to mouth. Most bivalves lack a radula. Cilia moves water through mantle cavity. c. Reproduction - Sexes are usually separate - broadcast spawn with fertilization in the plankton - zygote develops through morula stage to a planktonic veliger larvae (bivalved) - bivalved veliger sinks-swims and when competent will settle, no torsion (possibly to cue) - metamorphosis to mini adult d. Atypical bivalves - shipworms (look like worms but are clams with reduced sharp shells) e. Poisoning - care should be taken when eating any bivalves that may have PSP (see Plankton) Lesson 29, 30 diagrams 4. Class Cephalopoda (octopus, squid) a. Basic Body Form - Head in the middle with complex eyes and brain (most intelligent of invertebrates) - Crawl with the legs (8 in octopus, 10 in squid) or swim by jetting water out of the mantle with the siphon also most squid have fins near the end of the mantle and most octopus don't - Gills in mantle cavity - pumping of water thru mantle cavity by muscles of mantle (no cilia in mantle cavity) b. Feeding - usually carnivorous, catching prey with the legs, biting the prey with the beak, injecting poison and using the radula to scoop out the food c. Reproduction - separate sexed - internal fertilization (males develop a hectocotylus arm for sperm transfer, spoon shaped in the octopus and shovel shaped in the squid) that is often left in the female's mantle cavity) *Octopus usually mate as separate pairs. *Squid usually mate in large gatherings. - fertilized eggs (zygotes) laid - young hatch as miniature adults Octopus females watch over their strings of eggs until they hatch. Squid females lay eggs packed as "candles" and leave them. - both octopus and squid usually die after spawning d. Unique features species specific and mostly protective - Most with ink gland that empties into mantle cavity by siphon - used as smoke screen - Many have specialized skin cells called chromatophores (color change) for camouflage - Many have specialized skin cells to produce light called photophores - Many have skin-skin muscles (to change texture) for protection e. Poisoning - Poison may be toxic to man (Australia has octopus species that can kill man) - Care should be taken with bites from beak (beak itself not poisonous) Lesson 34, 80 diagrams III. Phylum Arthropoda - exoskeleton, molt to grow, autotomy = loss of appendages at will (Class Crustacea = marine arthropods, growth is by molting old exoskeleton, puffing up and forming new, larger exoskeleton, lost appendages may be regenerated during a molt) A. Basic Body Form - Segmented body, most segments with paired jointed appendages 1. Head a. One long pair antennae - touch b. One short pair antennae - chemical sensors c. One pair eyes -covered with exoskeleton 2. Thorax - usually with five pair legs 3. Abdomen - usually six segments - swimmerettes paired on first five segments, last segment with tailfan composed of central telson and flanked by uropods 4. Other a. Head and thorax may be covered with one shell called a carapace b. Bristles (touch, taste, sound, etc.) over body 5. Eight major types of Crustacea (seven listed here are typical, barnacles are variations) - Copepods: microscopic - 6 most common visible crustaceans (5 types and 2 kinds of crabs) i. Amphipods: laterally flattened, no carapace, large abdomen ii. Shrimp: laterally flattened, carapace, large abdomen iii. Isopods (marine pill bugs): dorso-ventrally flattened, no carapace, large abdomen iv. Lobster (and ghost or mud shrimp): dorso-ventrally flattened, carapace, large abdomen v. Anomuran crabs: dorso-ventrally flattened, large carapace, abdomen reduced and reflexed, antennae outside eyes vi. True crabs: dorso-ventrally flattened, large carapace, abdomen reduced and reflexed, antennae inside eyes B. Feeding - Most arthropods are scavengers except sand crabs (which are filter feeders) C. Reproduction in most 1. Separate sexed adults 2. Mating 3. Fertilized eggs (zygotes) kept by females under their abdomen. Newly fertilized eggs are orange and turn black as they develop 4. Development to zoea type larvae (single spine on head, exoskeleton), hatch as zoeas 5. MPL of marine crustaceans (zoea type) sink and swim (molting as they grow) 6. When competent they settle (possibly to a cue) and metamorphose (a molt) to a mini adult D. Atypical Forms = Barnacles: two kinds, volcanoe (acorn) or gooseneck type 1. Barnacle bodies are enclosed within accessory calcium shell(s) with legs covered with exoskeleton (molt exoskeleton around legs) 2. All barnacles are filter feeders (using their hairy legs) 3. Barnacles are hermaphroditic, cross fertilize, with planktonic larvae called nauplius, sink and swim, settle and metamorphose to a benthic barnacle E. Poisoning - none but one should always be aware of claws, spines, etc. Lesson 35, 36, 37, 81, 82, 83 diagrams IV. Phylum Echinodermata (starfish, brittle stars, sea urchins, sand dollars, sea cucumbers) A. General 1. Body plan is radially symmetrical for most species, a plan of 5 and a water vascular system (madrepore, for water entrance and exit, a system of vessels and tube feet) 2. Locomotion for most echinoderms is by tube feet (extensions of water vascular system) run by water pushed in and out of each tube foot 3. Reproduction (all groups) a. asexually by regeneration (some species of starfish can regenerate from a leg) b. sexually - separate sexed (each has five separate reproductive organs) - broadcast spawn - fertilization in seawater, mostly external - planktonic larvae called a pluteus-type - sink-swim of pluteus-type MPL - settles when competent (possibly to cue) - metamorphose to mini adult B. Four common classes 1. Class Asteroidea (true starfish) a. Basic Body Form i central disk with madrepore on top ii tube feet (most with suction cups)under legs (also called arms or rays) iii most species with pedicellariae (to keep clean) b. Feeding - most carnivorous with eversible stomach (remember rocky shore lectures) c. Great regeneration as long as a whole reproductive organ is present 2. Class Ophiuroidea (brittle starfish) a. Basic Body Form i Central disk with madrepore on bottom ii tube feet under legs - no suckers iii no pedicellariae b. Feeding - most filter feeders with mucus strands suspended on tube feet on legs, manipulate trapped plankton and pass to mouth (no eversible stomach) c. Regeneration of legs great (not for central disk), can drop legs if threatened and then regrow easily 3. Class Echinoidea (sea urchins, sand dollars) a. Basic Body Form - tube feet scattered over body, tipped with suckers, extend beyond spines (come from inside, out holes in 'test') - 5 reproductive organs open to outside separately on top (these gonads harvested for food, called uni and used in sushi) - mouth on underside (with 5 teeth called an Aristotle's Lantern) teeth extend 1/3 or so into depth of test - movable spines articulate from bumps on test held on with skin, these spines fall off when echinoids die and only the 'test' remains b. Feeding - most urchins are herbivores, sand dollars are filter feeders - both use Aristotle's lantern for this c. Poor regeneration, only minor repairs to test 4. Class Holothuroidea (sea cucumbers) a. Basic Body Form - tube feet in some species all over, in others only on one side (in 5's) - frilly tentacles in mouth used for feeding called feeding tree - when disturbed they blow up and become firm, if further disturbance, they eviscerate and regrow internal organs b. Feeding - most are filter feeders with feeding tree c. Poor regeneration of body covering but great regeneration after evisceration Lesson 39, 40, 41, 84 diagrams and 105 (sand dollars only)

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© 2000 Genny Anderson (Revised 15 April 6PM 2008)