MOLLUSK

1. MOLLUSK

2. General Mollusk Informatiom Sea Slug

3. Mollusk Terms • LATIN LIVES • Phora = Bearing • Mono = One • Placo = Plate • Cephalo = Head • Scapho = Sword • Pelecy = Hatchet • Poda = Foot

4. Phylum Mollusca Classes Click on any Scientific Name to go to that Class • Aplacophora- mollusks without shells • Pelecypoda ( Bivalve) - clams, oysters, mussels, second largest species. • Cephalopoda – squid, octopus, chambered nautilus • Gastropoda ( Univalve) – snails, slugs, abalones, whelks, periwinkles, giant conch, most species • Monoplacophora- mollusks with one shell, ancient • Polyplacophora ( Amphineura) – chiton, eight plates, intertidal • Scaphopoda - a tubular shell - tusk shells General information Interesting Facts Start Over

5. Invertebrates withSoft Bodies“Mollusk” octopus • They have existed for 600 million years. • Some are very primitive and some are quite intelligent creatures. • They are used commercially in many ways. squid snail

6. Mollusk ~ Snail • Second largest group in the animal kingdom • There are more than 150,000 living species of the mollusk. • Half of the species are marine.

7. MOLLUSK ANATOMY • Mollusks vary greatly in the development of each of the three body sections. • Three main body sections • Head = Eyes, Mouth ( Radula –rasping sucking tongue) and Tentacles • Visceral Mass = Mantle which secretes the shell, and the gills, intestines, kidneys, heart. • Foot = large muscular organ to move the body.

8. Mollusk Anatomy Visceral Mass Coelom Shell Mantle Heart Gonad Nephridium Esophagus Stomach Anus Intestine Gill Mouth Mantle Cavity Nerve Cords Foot

9. Mollusk reproduction • Most mollusks have separate females andmales; gonads are in the visceral mass ~ Sperm or eggs are produced by meiosis. • Snails are hermaphrodites bearing both female and male gonads in same individuals. Sea Slug

10. Class Monoplacophorans

11. Monoplacophorans • This is the deep- sea dwelling class that was the ancestor of all other mollusks. • These animals were thought to be extinct until 1952 • At present, only a few living species are known to exist. • There are many fossils .

12. Monoplacophorans • Nepolina

13. Monoplacophorans Fossil Specimens Cyrtolites Archinacella

14. Class Aplacophora

15. Aplacophorans • These organisms lack shells and are worm-like in body form. • They have calcareous scales or spicules in their integument.

16. Aplacophorans • Soleonogasters which also live on the bottom feed on cnidarians (Jellyfish – Corals).

17. Class Gastropoda Whelk

18. Mollusks Gastropoda (Univalve) • Class Gastropoda- • meaning stomach foot • Univalve = one valve or one shell Conch

19. Mollusks - Gastropods snails, slugs, abalones, whelks, periwinkles, giant conch • Largest – giant conch – 1 foot length • Urosalprix – “oyster drill” bores hole in oyster and digests through the hole.

20. Mollusks - Gastropods • Snails, nudibranchs, cowries, whelks

21. Sea Slugs

22. Nudibranchs with symbiotic algae

24. Glaucus atlanticus

25. Abalone The Abalone shell is used to make jewelry

26. Abalone Abalone is served in fine restaurants

27. Periwinkle

28. Periwinkle • Periwinkles feed on algae and seaweed. • They are found at the water's edge on Mash grasses. • They move up and down the grasses in synch with the tides.

29. Snails As Bird food • Snails provide an immense amount of food for waterfowl in the wetlands. • Mallard - 16% • Pintail - 15% • Blue winged Teal - 38% • Northern Shoveler - 40% • Gadwall - 4% • Whooping Crane – 60% The endangered Whooping Crane eats snails

30. Class Pelecypoda Oyster Shell

31. Phylum MolluscaClass Bivalvia ( PELECYPODA) • Class consist of; • clams, oysters, scallops, mussels mussels

32. What are the shells of mollusks made of? Oyster Shells • Calcareous material that resembles limestone

33. Scallop Eyes Gills (Cilia)

34. Clam Gills with Cilia

35. What do clams use for digging into the sand? • A muscular, hatchet-shaped footextends from • between the shells and is used for digging.

36. Class Cephalopoda Octopus

37. Cephalopoda • Class Cephalopoda are among the most active, interesting and intelligent of the Mollusk. • Cephalopoda means head-foot. Their head is attached to the foot which become tentacles octopus

38. Class Cephalopoda octopus • Shell reduced & internalized in squid ( beak) • No shell in octopus • Largest invertebrates • Possess eyes and tentacles

39. Mollusks - Cephalopods octopus • All are carnivorous • Siphon allows jet propulsion in squid • Defenses include ink (squid, octopus) and change in coloration of octopus

40. Mollusks - Cephalopods • Squid, chambered nautilus, cuttlefish, octopus

41. Squid • Shell reduced to pen made of chitin

42. CuttleFish Cuttlefish Cuttlefishes have Carbonate shells

43. cephalopods • The only cephalopods with a shell are a few species of nautiluses • Nautilus means shell with chambers. Nautilus

44. Class Polyplacophora Chiton

45. Class Polyplacophora • Habitat: Chitons inhabit the intertidal and subtidal regions. • They live under or on rocks with a very tight grip to protect them from waves. • Each one consists of Eight plates • Diet: Encrusting plants and animals • Reproduction: Chitons are dioecious, meaning there are female chitons and male chitons.

46. Chiton

47. Gumboot Chiton • It is the largest species of chiton in the world, • It can grow up to 30 cm in length

48. Class Scaphopoda

49. Scaphopoda • The Scaphopoda are known as the "tusk shells" because their shells are conical. • The scientific name Scaphopoda means "shovel foot", which refers to the "head" of the animal. It lacks eyes and is used for burrowing into marine mud and sediments.

50. Scaphopoda • The most distinctive feature of scaphopods is that the tubular shell is open at both ends, • Not just one end as in most molluscs.