Phylum Mollusca 1
Mollusca Vocabulary Complete a vocab grid. Color on front. Remember to draw & # squares on back. Some are in text and NOT in the glossary. BE THOROUGH 1.Trochophore 2.Mantle 3.Visceral Mass4.Ganglion 5.Mantle Cavity6.Radula 7.Gastropoda(class)8.Hemolymph 9.Hemocoel10.Bivalvia (class) 11.Incurrent Siphon12.Cephalopoda (class) 13. Excurrent Siphon14. Hydrostatic skeleton 2
PREVIEW CARDS I. Characteristics of phylum Mollusca (pg. 190, 192) II. Identify examples of the 3 main classes: Gastropoda, Bivalvia, Cephalopoda III. Explain the importance of torsion IV. 3 plausible advantages of torsion V. Shell and associated structures of bivalves VI. Sketch of Bivalve shell Fig VII. Bivalve diversity VIII. Cephalopod shell or lack thereof IX. Chromatophores in cephalopods
Taxonomy Kingdom:Animalia Phylum: Mollusca Class:Gastropoda Bivalvia CephalopodA 4
Phylum Mollusca 5
Mollusks 50, ,000 living species 35,000 extinct species Largest = 1000 pounds 80% less than 5 cm 6
Name comes from latin “molluscus”, meaning soft body Most have a shell Most marine 7
Phylum Mollusca Triploblastic Symmetry: Bilateral Coelomate Protostomes 8
Mollusca share 3 common features: A muscular foot – usually for movement A visceral mass – including internal organs A mantle – envelopes visceral mass and secretes a shell 9
Dorsal mantle covers the visceral mass. 10
Secretes the shell 11
Gills (Respiration) 12
Complete digestive system 13
Paired ventral nerve cords 14
Radula 15
Coelom - metanephridia 16
Body Plan 17 Mantle cavity GillsGills Pericardial cavity MetanephridiumMetanephridium RadulaRadula GonadGonad Stomach and digestive gland FootFoot
Mollusk General Anatomy
Class Bivalvia Clams, Oysters, Shipworms, mussels, Scallops 19
Class Bivalvia Two shells Most are filter feeders No head or radula Burrow –Sand, wood, rocks 20
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Bivalve Anatomy
Giant Clam & Burrowing Clam 23 Siphon Ywkhttp:// Ywk burrowing clam Pismo clam
Giant Clam 24
Zebra Mussel Environmental Pest Ballast water of ships from Europe in 1986 Attack by secreting adhesive byssal threads –Each other –Other mussels –Man made objects Pipes, plumbing 25
Zebra Mussel Live in high densities Feed on phytoplankton Reproduce rapidly 26
Zebra Mussel Attach to native mussels Killed all native mussels in Lake Erie 27
Distribution of Zebra Mussel 28
ZEBRA MUSSEL INFESTATION regulations-will-impact-lake-users/ regulations-will-impact-lake-users/ 54/the-threat-of-zebra-mussels-in-bc-a-short- document 29
Oyster Ecology 30
Oysters in NYC 31 m/watch?v=IFnbnJ8k GQQ
Oysters – The Ultimate Filters 32 yMpHsaQ
Scallops have fan shaped shell 33
Scallop Facts Unlike other bivalves like mussels and clams, most scallops are free-swimming. swimming scallop They swim by clapping their shells quickly, which moves a jet of water past the shell hinge, propelling the scallop forward Scallops have about 60 eyes that line its mantle. These eyes may be a brilliant blue color, and allow the scallop to detect light, dark and motion escaping seastar mantle 34
Shipworms not worms at all, but rather a group of unusual saltwater clams with long, soft, naked bodies they drill passages by means of a pair of very small shells borne at one end, with which they rasp their way through. Sometimes called "termites of the sea”clams 35 outube.com/ watch?v=A HcHNoOyv 5Ihttp:// outube.com/ watch?v=A HcHNoOyv 5I eating shipworms
Class Gastropoda Snails, Slugs, Conchs, Limpets, Whelks, Nudibranchs, Abalones 36
Class Gastropoda Largest Class of Mollusks about 35,000 species One shell (if present) Torsion of body (visceral mass twists 180° during development) 37
Torsion 38
Gastropod Open circulatory system Fluid called Hemolymph 39
Snail Terrestrial Mantle cavity functions as lung 40
Snail 41 Tentacle (Eye stalks) TentacleTentacle PneumostomePneumostome AnusAnus FootFoot MouthMouth Genital pore ShellShell Add foot and make it #8
Snails 42
CONE SNAIL search_query=tueb+snail+eats+fis h&aq=f search_query=tueb+snail+eats+fis h&aq=f 43 JrrKk
Nudibranch No shell Nudibranchs get their bright colors from the food they eat. Dorsal projections -Gills -Nematocyst discharge by preying on organisms with nematocyst
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Spanish Dancer Nudibranch 46 hsmbY
ABALONE ABALONE Several holes in top of shell –Excrete waste Food for man 47
Slug No shell Garden pests 48
Limpet Herbivores Cling to rocks or other surfaces 49
Conch Large shell Marine Many are predators 50
Giant Conch 51 com/watch?v=TaaZD 6gX4Rw
Class Cephalopoda Squids, Octopuses, Nautiluses, Cuttlefish 52
Class Cephalopoda “head footed” Shell in squid and octopus absent or vestigial (serves no obvious purpose) Jet propulsion Ink sac for defense Foot modified into arms and tentacles Marine All predators Roughly 700 living species 53
Squid 54 Dorsal Ventral Posterior surface Right Left
Squid 55 FinFin ArmArm Funnel (siphon) EyeEye TentacleTentacle CollarCollar
Squid 56 Shell (Pen) Ctenidium (gills) FunnelFunnel SystemicheartSystemicheart Branchial heart
Squid Male 57 TestisTestis Hectocotylous arm PenisPenis
Squid Female 58 Ovary with eggs Nidamental glands Oviducal gland Oviducal opening
Squid
VIRTUAL SQUID DISSECTION orner.com/workshee ts/squid_virtual.html 60
Octopus Eight arms with suckers Crawl or eject water from siphon Change skin color –chromatophores Most intelligent invertebrate 61
Giant Octopus vs shark geographic.com/vide o/player/animals/inv ertebrates- animals/octopus- and- squid/octopus_giant _kills_shark.html 62
WOW, Giant Octopus! 63 com/watch?v=lwAqh Thd_EQ
Intelligent Octopus 64 com/watch?v=bBe2K aRuI80
Nautilus Indian & Pacific ~ 1,800 feet Avg. life span = 20 years ( unusual – most cephalopods have short life span) Average size 8-10 inches in diameter Up to 94 tentacles –No suckers Shell with many chambers –Lives in outermost chamber 65
Nautilus 66 com/watch?v=QMFq V4SJLWg
Cuttlefish v1mxpR0&feature=relatedhttp:// 8v1mxpR0&feature=related A6B41SQQ&feature=relatedhttp:// A6B41SQQ&feature=related w7QroV78 mating in mozambiquehttp:// w7QroV78
Cephalopod – Master of Disguise 68 com/watch?v=5rqho mPaxhEhttp:// com/watch?v=5rqho mPaxhE com/watch?v=IyeKb RIQTxs&feature=rel ated
The End 69