1. Coelomates: Mollusks and Annelids

2. Coelomates (Eucoelomates) Have body cavity Peritoneum present: from mesoderm

3. Phylum Mollusca (mollusks) Large: 110,000 described species (#2 behind arthropods!) Bilateral symmetry, _____________ Body usually has calcareous shell, muscular foot, head.

4. Phylum Mollusca (mollusks) Mantle: fold of tissue that wraps around body. –Secretes shell –Gills are specialized mantle portion to extract oxygen from water Organs: stomach, heart, gills, etc.

5. Phylum Mollusca (mollusks) Often have radula in mouth Usually ____________ Radula

6. Phylum Mollusca (mollusks) Circulatory system open. Heart 3 chambers (2 collect blood from gills, one pumps to body) Coelom is cavity around heart.

7. Phylum Mollusca (mollusks) Excretory system: ____________ gather nitrogenous wastes from coelom, discharge them into mantle cavity. Can reabsorb valuable solutes so they aren’t lost

8. Phylum Mollusca (mollusks) Class Bivalvia (bivalves) Class Gastropoda (gastropods) Class Polyplacophora (chitons) Class Cephalopoda (cephalopods)

9. Class Bivalvia (bivalves) Body contained between 2 hinged shells (valves) Foot hatchet-like, modified for burrowing in sand/mud Little cephalization: no head, no ___________

10. Class Bivalvia (bivalves) Adductor muscles (2 in most bivalves) close _____________ Cilia on gills pull water into and out of shell through siphons. Brings oxygen, food particles

11. Class Bivalvia (bivalves) Importance: –1) biodiversity –Ex, freshwater mussels. Many Alabama species endangered, some extinct –Used to be harvested to make buttons from shells

12. Class Bivalvia (bivalves) Importance: –Larvae parasitic on host fish gills or fins as glochidia –How get fish to come close to receive glochidia?

13. Class Bivalvia (bivalves) Importance: –Lure them in! –Mantle of female mussel mimics fish.

14. Class Bivalvia (bivalves) Importance: –2) pollution monitors –Aquatic filter feeders (mussels) process large quantities of water during feeding –Concentrate metals, pesticides, PCBs. –Sample tissues periodically to detect pollution –California Mussel Watch Program, National Mussel Watch Program.

15. Class Bivalvia (bivalves) Importance: –3) human food (clams, oysters, scallops, mussels) clams mussels oysters

16. Class Bivalvia (bivalves) Importance: –3) human food (clams, oysters, scallops, mussels) Scallops have one large (edible) adductor muscle

17. Class Bivalvia (bivalves) Importance: –4) jewelry (pearls)

18. Class Bivalvia (bivalves) Importance: –5) invasive species. Ex, zebra mussel from Caspian Sea –Colonies encrust exposed surfaces (mussels are filter feeders) –Can kill freshwater clams (wiped them out in Lake Erie)

19. Class Bivalvia (bivalves) Importance: –5) invasive species. –Cleaning water intake pipes will cost $3.1 billion over next 10 yr.

20. Class Polyplacophora (chitons) Small group: 600 species Marine, rocky intertidal zone Graze algae from rocks Have 8 overlapping valves Cling to rocks with foot. Gumboot chiton: largest in world

21. Class Gastropoda (snails/slugs/limpets) Single shell present (usually coiled in snails) or lacking (slugs) Foot flattened, modified for crawling Head with eyes, tentacles Radula modified as _________ (many herbivores, some predators)

22. Rare snails Land snails diverse group On islands, have radiated into many species Ex, Partulid snails from S. Pacific.

23. Rare snails 120 species in family Partulidae Moorea, small S. Pacific island.

24. Rare snails Moorea had 7 species of Partulid snails found nowhere else on Earth.

25. Rare snails Problem: Giant African snail introduced to island Damaged agriculture.

26. Rare snails Solution (new Problem): Introduce predatory Euglandina snail Wasn’t supposed to invade areas containing Partulid snails and eat them But it did.

27. Rare snails By 1987 all Partulid snails on Moorea were extinct in wild But 6 of 7 species are being maintained in captivity by several zoos.

28. Rare snails Ex, white abalone Marine snail, coast S. California. lives on submerged rocks, eats algae. Has large foot which is delicious. Shells of red abalone

29. Rare snails Ex, white abalone Fishery developed in 1970s, when populations were 1,000-5,000/acre Quickly overharvested them Now <1 abalone/acre left (maybe 1,600 total) Listed endangered 2001

30. Rare snails Ex, white abalone Problem: Don’t move about much. Depend on water to mix sperm and eggs. Males/females must be about 3 feet apart for fertilization to occur! Density now too low for reproduction in wild Captive breeding program underway. Female releasing eggs (can make 3 million!

31. Other uses of snail shells Seashell collectors This rare specimen is for sale: $7,000

32. Other uses of snail shells Shell money: early form of currency (before coins) Sumerian shell ring money: Syria 3000BC S. Pacific shell money

33. Class Gastropoda (snails/slugs) Nudibranchs (naked gills) ____________. Some can eat cnidarians and transfer nematocysts to their gills to defend them from enemies!

34. Class Cephalopoda Foot divided into arms/tentacles –Squids: 10 tentacles. Octopuses and cuttlefish: 8. Nautiluses: 80-90. Tentacles with suckers

35. Class Cephalopoda (octopuses, squids, nautilus) Have ______________ Have extreme cephalization Shell absent (octopus, squid), internal (cuttlefish: cuttlebone), or present (nautilus) Swim by taking water into mantle cavity and expelling it through siphon (jet propulsion)

36. Class Cephalopoda Excellent vision Intelligent Have both long-term and short-term memory Ex, one aquarium octopus helps clean its aquarium by handing debris to staff Common octopus

37. Class Cephalopoda Deadly (Octopussy) Blue-ringed octopus: bite deadly due to tetrodotoxin (neurotoxin) No known antidote Fashionable pet in Thailand.

38. Phylum Annelida (segmented worms) 11,000 species (2/3 marine) Bilaterial symmetry, triploblastic Protostomes Eucoelomates: Coelom fluid-filled and pressurized. Provides hydrostatic skeleton

39. Phylum Annelida (segmented worms) Note circular and longitudinal muscles Cephalization, complete digestive tract

40. Phylum Annelida (segmented worms) Closed circulation system (arteries, veins, capillaries). Note dorsal and ventral blood vessels. Dorsal moves blood to head, ventral toward tail. Multiple ____________.

41. Phylum Annelida (segmented worms) Excretory system: metanephridia Bristles (setae) on body. Sensory or aid in locomotion

42. Phylum Annelida (segmented worms) Monoecious. Gonads: where sperms and eggs made Worms mate by passing sperm to each other Mating Earthworms

43. Phylum Annelida (segmented worms) Clitellum located near reproductive organs Clitellum secretes ___________. Sheath collects eggs/sperm as it slides off worm to form cocoon Young worms develop in cocoon. Earthworm cocoons and head of pin

44. Phylum Annelida (segmented worms) Segmented body: Key characteristic. Body series of compartments with similar systems in each Advantages –1) Allows adjacent segments to operate independently, give precise control of body movement (expand and contract segments) –2) System redundancy: if one segment injured, others contain muscles, nerves, excretory, circulatory systems that can continue to function.

45. Class Oligochaeta (earthworms) Most familiar group Few setae, head poorly developed Cuticle outside epidermis Detritivores: Feed on organic matter in soil. Castings rich in minerals. Burrowing causes soil aeration Flooding rains can drown them Large Australian earthworm

46. Class Polychaeta (polychaetes) Marine. Most species in this class. Important members of marine ecosystems. Parapodia (paddle-like appendages) present with setae on them Head well-developed. Usually dioecious, ____________ external

47. Class Polychaeta (polychaetes) Examples in lab: plume worm, clam worm Clam worm Plume worm (lives in tube) Filters water for food with tentacles

48. Class Hirudinea (leeches) 1 or 2 suckers present: anterior (head end) and posterior (tail end) No setae or _______________ No septa between segments (superficial segmentation: not segmented within body)

49. Class Hirudinea (leeches) Parasites or predators. Mostly freshwater. Parasites: Asian ones terrestrial (tropics). Detect heat and vibrations Others aquatic.

50. Class Hirudinea (leeches) Parasites: have anticoagulant (so blood doesn’t clot) and anesthetic (so leech not noticed) in saliva Medical use: can relieve inflammation and swelling better than medication

51. Lophophorates 3 marine phyla with special feature: ________________ Lophophore: Circular or U-shaped ridge around mouth, bearing 1 or 2 rows of hollow ciliated tentacles Cilia trap detritus/plankton (filter feeders) and tentacles aid in gas exchange Have mix of protostome and deuterostome features (classification uncertain)

52. Lophophorates Phylum Phoronida (phoronids) –Live in tube. Feed with tentacles. –Have U-shaped gut –Only 10 species

53. Lophophorates Phylum Ectoprocta (bryozoans) –Like small phoronids (U-shaped gut). Marine and freshwater. 4000 species –Live in colonies. Produce ____________: chitinous chamber that connects colony members.

54. Lophophorates Phylum Brachiopoda (brachiopods) –Have 2 calcified ______________ (look like clams) –Attach valves to substrate with pedicel –Open valves to feed with lophophore –300 species now. Cold water marine.

55. Lophophorates Phylum Brachiopoda (brachiopods) –Big fossil record (30,000 species described) –Dominant in Paleozoic Era (543-248 million years ago) –Useful fossils for dating sediments or characterizing ocean conditions in past

56. Phylum Arthropoda (arthropods)

57. Most successful of all animal phyla Everywhere: Terrestrial, aquatic

58. Phylum Arthropoda (arthropods) Huge group: 70% of all named animal species. At least 1,000,000. 80% of arthropods are insects (Class Insecta), and 50% of insects are beetles (Order Coleoptera)

59. Phylum Arthropoda (arthropods) Closely related to annelids

60. Phylum Arthropoda (arthropods) General characteristics: –1) Eucoelomates, bilateral symmetry, ___________

61. Phylum Arthropoda (arthropods) General characteristics: –2) Body segmented. Ancestral trait is many ________ segments. In derived groups, segments fused into functional units (tagmata). –Regions: head, thorax, abdomen. If head and thorax are fused, called cephalothorax

62. Phylum Arthropoda (arthropods) General characteristics: –3) Extreme cephalization (head with many sense organs). Example: compound eye. Made of ommatidia (each a single eye with ________). May also have simple eyes (ocelli) with single lenses.

63. Phylum Arthropoda (arthropods) General characteristics: –3) Compound eyes see the world in a different way –Advantage: detection of motion.

64. Phylum Arthropoda (arthropods) General characteristics: –4) Innovation: Have exoskeleton; hard coating of ________ on outside of body –Secreted by epidermis. Protects against enemies, water loss (on land). Provides attachment points for muscles and organs

65. Phylum Arthropoda (arthropods) General characteristics: –Problem: can’t grow. Must be shed during molting. –Problem: will not support large body volume efficiently. Larger body has much greater surface area. Keeps arthropods ______________ Softshell blue crab in the making...

66. Phylum Arthropoda (arthropods) General characteristics: –5) Innovation: Have jointed appendages (legs, antennae, mouthparts) “arthros” (Gr.)=jointed. “podes” (Gr.)=feet –2 types. Biramous have 2 branches, uniramous have 1 branch

67. Phylum Arthropoda (arthropods) General characteristics: –6) Circulatory system open. Heart pumps blood toward head, then flows back through body

68. Phylum Arthropoda (arthropods) General characteristics: –7) Nervous system. Brain small. Ventral ganglia control many body activities

69. Phylum Arthropoda (arthropods) General characteristics: –8) Respiratory system –Terrestrial: Most have spiracles, which open into tracheae that branch into ______________ –Some (ex, spiders) have book lungs, leaflike plates in chamber –Aquatic: gills

70. Phylum Arthropoda (arthropods) General characteristics: –9) Excretory system –Varied. Malphigian tubules bathed in blood, collect fluid, dump wastes in hindgut. Reabsorb water and salts in hindgut