1. INVERTEBRATES Mollusca, Annelida, Arthropoda, Echinodermata Animals that lack vertebrae (classed by a characteristic they don’t have.) 97% of all species on Earth are invertebrates.

2. Phylum Mollusca Phylum Mollusca

3. More species (200,000+) than any other animal phylum except Arthropoda More species (200,000+) than any other animal phylum except Arthropoda Soft body – often protected by CaCO 3 shell Unsegmented, typically bilaterally symmetrical Phylum Mollusca Phylum Mollusca ©2004 Amanda Demopoulos

4. Mollusca: Major Characteristics 1.Cephalization have a distinct head with sense organs & brain (mostly) 2.Bilaterally symmetrical (mostly) SNAIL, CLAM, CHITON, & SQUID

5. Basic Mollusk Body Plan Head (eyes/sensory), visceral mass (organs), muscular foot Mantle – covers visceral mass, secretes shell Radula – Ribbon of small chitin teeth used in feeding Gills (ctenidia-comb like) for gas exchange in mantle cavity

6. Radula – Ribbon of small chitin teeth used in feeding

7. 4 Classes of Mollusca 1.Class Polyplacophora Many-plate-bearing = Chitons 800 species Mostly graze algae on rocky shorelinesMostly graze algae on rocky shorelines Exclusively marineExclusively marine 8 overlapping plates8 overlapping plates

8. 2. Gastropoda snails, slugs, nudibranchs, conchs & abalone

9. Most gastropods are herbivores Class Gastropoda

10. Stomach-Foot (class Gastropoda) contains about 70% of all mollusk species. A few stomach-foots are found on land. The stomach-foot include: snails, limpets and abalones, which have shells. Slugs and nudibranchs are also stomach- foots, but do not have shells. Stomach-Foot

11. Abalones Snails Snails Snails

12. Nudibranchs

13. 3. Pelecypoda or Bivalvia clams, oysters, & mussels No head and no radula

14. Most bivalves are suspension feeders Class Bivalvia

15. Bivalvia Anatomy

16.  Hinged, 2-valved shell  (oysters, clams, mussels,  (oysters, clams, mussels, scallops) muscles keep closed  No head, no radula  Sedentary lifestyle  Some have muscular foot for burrowing (clams) used for suspension feeding & respiration  Gills used for suspension feeding & respiration  Water enters and leaves through siphons  Some anchor to substrate (mussels)  Scallops – Swim! (repeated clapping of valves) Swim Class Bivalvia

17. 4. Cephalopoda squid, octopus, & nautilus

18. Class Cephalopoda - Octopus and squid have beak-like jaws - Mouth is central among tentacles Octopus 8 arms, non-retractable w/ 2 rows of suckers Nautilus 60-90 suckerless tentacles Squid 8 arms + 2 tentacles non- retractable w/suckers and hooks Cuttlefish 8 arms + 2 tentacles, retractable w/ suckers, no hooks

19. Cephalopods (a) (b) (c) Note the different shells in cephalopods - external in Nautilus, internal in squids, and missing in octopuses. Octopuses are considered among the most intelligent invertebrates. Chambered nautiluses are the only living cephalopods with an external shell. Squids are speedy carnivores with beaklike jaws and well-developed eyes.

20. PHYLUM Annelida  Earthworms  Leeches  Tubeworms

21. Annelids: Major Characteristics 1. Cephalization 2. Bilateral symmetry 3. Coelom well developed and divided by septa (except in leeches); coelomic fluid supplies turgidity and acts as a hydrostatic skeleton Segmented worms (1mm-3m) Body composed of repeated segments Body composed of repeated segments

22. Annelids: Major Characteristics Body wall Outer circular and inner longitudinal muscle layers Protective elastic outer transparent moist cuticle secreted by epithelium Closed circulatory system Respiratory gas exchange through skin, gills or parapodia Digestive system of many has 2 openings, mouth and anus (some have no gut)Digestive system of many has 2 openings, mouth and anus (some have no gut) Excretory system Nervous systems

23. 1. Polychaeta Tubeworms, feather dusters, bristle worms, mainly marine Free-living predators Free-living predators Burrowing Burrowing Tube building Tube building Three Classes Body segments have pairs of parapodia locomotion locomotion feeding feeding gas exchange gas exchange protection protection tipped with setae (bristles), often 4 pairs tipped with setae (bristles), often 4 pairs

25. 2. Oligochaeta Earthworms, mainly terrestrial and freshwater Earthworms, mainly terrestrial and freshwater Few marine species Few marine species Benthic – mud and sand (deposit feeders) Benthic – mud and sand (deposit feeders) No parapodia No parapodia Locomotion – expansion and contraction Locomotion – expansion and contraction Three Classes

26. Earthworm Anatomy

27. Annelid Movement

28. 3. Hirudinea Leeches Hirudin – anticoagulating chemical so blood does not clotHirudin – anticoagulating chemical so blood does not clot mainly freshwater but with marine and terrestrial species No parapodiaNo parapodia One anterior/one posterior sucker One anterior/one posterior sucker Three Classes

29. Phylum Arthropoda Phylum Arthropoda The vast majority of known animal species, including insects, crustaceans, and arachnids, are arthropods. All arthropods have segmented exoskeleton and jointed appendages.

30. Most species of any phylum – over 1 million - 75% of all animals species describedMost species of any phylum – over 1 million - 75% of all animals species described Insects, spiders, centipedes, crabs, lobsters, shrimp, barnacles, etc.Insects, spiders, centipedes, crabs, lobsters, shrimp, barnacles, etc. Segmented, bilaterally symmetrical body Segmented, bilaterally symmetrical body Jointed appendagesJointed appendages Exoskeleton made of chitinExoskeleton made of chitin Growth requires molting - defenselessGrowth requires molting - defenseless Body segments Body segments Head, thorax, abdomenHead, thorax, abdomen Some groups have head and thorax fused = cephalothorax Some groups have head and thorax fused = cephalothorax Discuss 3 subphyla and representative classes Discuss 3 subphyla and representative classes Phylum Arthropoda

31. A.Class Merostomata (=legs attached to mouth) Horseshoe crabs-Not true crabsHorseshoe crabs-Not true crabs Named for feeding appendages – cheliceraeNamed for feeding appendages – chelicerae Distinctive, horseshoe-shaped carapaceDistinctive, horseshoe-shaped carapace No antennaeNo antennae Benthic predators/scavengers on clams and small invertebratesBenthic predators/scavengers on clams and small invertebrates No jaws - Grind food with bristles on walking legs (must be walking to “chew”)No jaws - Grind food with bristles on walking legs (must be walking to “chew”) Much of what we know understand about vision based on horseshoe crab eyesMuch of what we know understand about vision based on horseshoe crab eyes Blood is used to test injectable pharmaceutical solutions for bacterial contaminationBlood is used to test injectable pharmaceutical solutions for bacterial contamination 1. Subphylum Chelicerata

32. B. Class Pycnogonida (= thick knees, Sea spiders) All marine All marine Superficially resemble spiders Superficially resemble spiders Mouth at end of large proboscis Mouth at end of large proboscis Carnivores Carnivores Feed on sea anemones, hydrozoans,Feed on sea anemones, hydrozoans, other soft invertsother soft inverts Legs much longer than body, more than 8 Legs much longer than body, more than 8 2. Subphylum Chelicerata

33. C. Arachnida spiders, scorpions, mites Largest class in Chelicerata Largest class in Chelicerata Cephalothorax and abdomen Cephalothorax and abdomen Mouth called chelicerae (first appendage Mouth called chelicerae (first appendage Pinchers or fangsPinchers or fangs Pedipalps Pedipalps Second pair of appendagesSecond pair of appendages Handle prey, sensoryHandle prey, sensory Four pair of walking legs Four pair of walking legs 2. Subphylum Chelicerata

34. Arachnids PHOTO: Bill Rudman Chelicerae are feeding appendages

35. Cheliceriform Anatomy

36. Class Trilobita MarineMarine Extinct since 250 myaExtinct since 250 mya Rich fossil history because of exoskeletonRich fossil history because of exoskeleton Dorso-ventrally flattenedDorso-ventrally flattened

37. Contains majority of marine arthropod speciesContains majority of marine arthropod species Gills + two pairs of antennae (sensory)Gills + two pairs of antennae (sensory) Larval forms – nauplius and zoeaLarval forms – nauplius and zoea A. Class Copepoda (=oar foot, Copepods) Extremely abundant holoplankton (always plankton)Extremely abundant holoplankton (always plankton) Some live on/in substrates (benthos)Some live on/in substrates (benthos) **Among most abundant animals on earth****Among most abundant animals on earth** Important primary consumers of phytoplanktonImportant primary consumers of phytoplankton Small << 1-2 mmSmall << 1-2 mm Some parasitic formsSome parasitic forms 3. Subphylum Crustacea (40K species)

38. B. Class Cirripedia (= hairy foot, Barnacles) Active suspension feeders (filter feeders)Active suspension feeders (filter feeders) Use feathery cirri (modified swimming appendages)Use feathery cirri (modified swimming appendages) Sessile (attached to surfaces- whales, piers)Sessile (attached to surfaces- whales, piers) Fouling organisms (boats, whales)Fouling organisms (boats, whales) Resemble mollusks superficially – calcareous platesResemble mollusks superficially – calcareous plates 3. Subphylum Crustacea

39. C. Class Malacostraca (=soft shell, 75% crustacean species-Discuss 4 Orders) 1. Order Amphipoda (Amphipods) beach hoppers, sand fleas, whale lice Laterally compressed Laterally compressed Generally small (< 2 cm), but larger in deep ocean Generally small (< 2 cm), but larger in deep ocean Head and tail downward Head and tail downward Widespread distribution Widespread distribution Generally free living Generally free living Important scavengers Important scavengers 3. Subphylum Crustacea

40. C. Class Malacostraca 2. Order Isopoda (Isopods-rock lice, fish lice) Dorsoventrally compressedDorsoventrally compressed Generally small (< 2 cm), but larger in deep ocean Generally small (< 2 cm), but larger in deep ocean Related to terrestrial pill bugsRelated to terrestrial pill bugs Widespread distributionWidespread distribution Generally free living Generally free living Important scavengers Important scavengers Some parasites Some parasites 3. Subphylum Crustacea

41. C. Class Malacostraca 3. Order Euphausiacea (Krill) - holoplankton Laterally compressedLaterally compressed Up to 10 cm long (usually smaller) Up to 10 cm long (usually smaller) Head and anterior segments fused to form distinct carapaceHead and anterior segments fused to form distinct carapace Widespread distributionWidespread distribution Important primary consumers and predators Important primary consumers and predators Important prey for larger consumers (whales, penguins, fish) Important prey for larger consumers (whales, penguins, fish) Keystone species in some ecosystems (Polar, Southern Ocean) Keystone species in some ecosystems (Polar, Southern Ocean) Aggregate in schools (billions of individuals)Aggregate in schools (billions of individuals) 3. Subphylum Crustacea

42. C. Class Malacostraca 4. Order Decapoda (=10 legs, Crabs, Lobsters, Shrimps) Most species in Crustacea (~10,000) Scavengers/Predators/Both Largest crustaceans Five pairs of walking legs (deca=10) First pair usually modified as claws for feeding/defense Well-developed carapace = cephalothorax Rest of body = abdomen, tail Laterally compressed, except crabs – abdomen under cephalothorax 3. Subphylum Crustacea

43. Fig. 7.30

44. 4. Subphylum-Uniramia A. Class Insecta = Hexapoda (6 footed) 1 million species described to date 1 million species described to date Found in every known terrestrial + freshwater habitat, some marine except deep sea Found in every known terrestrial + freshwater habitat, some marine except deep sea Diversity attributable to Diversity attributable to Feeding specializationFeeding specialization Dispersal capabilitiesDispersal capabilities Predator-avoidance possibilities (flight)Predator-avoidance possibilities (flight)

45. Tracheal tubes are used in gas exchange “Insects are more species rich than all other forms of life combined.” Insect wings are modified cuticle, not appendages 4. Subphylum-Uniramia A. Class Insecta = Hexapoda (6 footed)

46. Insect Anatomy

47. In incomplete metamorphosis (not shown), the juvenile looks like the adult Complete Metamorphosis

48. 4. Subphylum-Uniramia A. Class Diplopoda = 2 pair of legs per segment = millipedes B. Class Chilopoda = 1 pair of legs per segment = centipedes Millipedes, herbivores, were perhaps the first land animals Centipedes are carnivores

49. Echinoderms, such as sand dollars, sea stars, and sea urchins, are aquatic animals that display radial symmetry as adults. They move and feed by using a network of internal cannals to pump water to different pars of the body. Phylum Echinodermata

50.  “Spiny skin” 6000 species  Sea lilies, feather stars, brittle stars, sea stars, sand dollars, sea urchins, sea biscuits, sea cucumbers  Radial symmetry  Endoskeleton = hard plates, ~95% calcium carbonate, covered by skin  Complete digestive, nervous systems, and reproductive organs  Regeneration  Water vascular system = internal hydraulic system Phylum Echinodermata

51. Sea stars posses multiple arms, upon which are numerous tube feet, and a calciferous endoskeleton Sea Stars

52.  Tube feet (podia) extended by pressure from ampullae (muscular sacs)  Tube feet used for locomotion, feeding, sensory functions Phylum Echinodermata

53. Crown of Thorns Acanthaster planci

54. Echinoderm Anatomy

56. The End