molluscs. molluscs/mollusks over 200,000 species of molluscs more marine species than any other...
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MolluscsMolluscs
Molluscs/MollusksMolluscs/Mollusks Over 200,000 species of molluscsOver 200,000 species of molluscs More marine species than any other More marine species than any other
PhylumPhylum Most have soft bodies enclosed in Most have soft bodies enclosed in calcium calcium
carbonate shellcarbonate shell..
StructureStructure Body covered by Body covered by mantlemantle, thin tissue that , thin tissue that
secretes the shellsecretes the shell Have ventral, muscular Have ventral, muscular footfoot, for , for
locomotionlocomotion Have head w/ eyes & sensory organsHave head w/ eyes & sensory organs RadulaRadula
unique to molluscsunique to molluscs ribbon of small teeth used to feedribbon of small teeth used to feed made of chitin (highly resistant carbohydrate)made of chitin (highly resistant carbohydrate)
Body FunctionsBody Functions Nervous SystemNervous System - well-defined with a primitive - well-defined with a primitive
brain; ganglia = “local brains” in different parts of brain; ganglia = “local brains” in different parts of bodybody
Circulatory systemCirculatory system – blood vessels & 2- – blood vessels & 2-chambered heartchambered heart
Digestive systemDigestive system - usually includes a jaw, - usually includes a jaw, salivary glands, pharynx, esophagus, stomach, salivary glands, pharynx, esophagus, stomach, intestine and anusintestine and anus
Reproductive systemReproductive system – separate sexes & – separate sexes & external fertilization external fertilization
Respiration systemRespiration system –gills –gills
Types of MolluscsTypes of Molluscs All molluscs have basic body plan but All molluscs have basic body plan but
greatly modified depending on class.greatly modified depending on class. 3 Main Classes:3 Main Classes:
CephalopodaCephalopoda (Cephalopods) (Cephalopods) GastropodaGastropoda (Gastropods) (Gastropods) BivalvesBivalves (Bivalvia) (Bivalvia)
CephalopodsCephalopods Name means “head-footed”Name means “head-footed” 650 species, all marine650 species, all marine Predators specialized for locomotionPredators specialized for locomotion Includes: octopus, squid, cuttlefish, & other Includes: octopus, squid, cuttlefish, & other
fascinating molluscsfascinating molluscs
Class Gastropoda Class Gastropoda
Largest and most varied class of molluskLargest and most varied class of mollusk 90,000 species90,000 species Gastropod (stomach foot)Gastropod (stomach foot) Foot on ventral side (stomach)Foot on ventral side (stomach) Examples: Snails, limpets, abalones, Examples: Snails, limpets, abalones,
nudibranchsnudibranchs
SnailsSnails
NudibranchsNudibranchs
Class BivalviaClass Bivalvia
Body compressed and enclosed in a Body compressed and enclosed in a two two valved shellvalved shell
Very small head, no radulaVery small head, no radula Gills expanded and folded and used to Gills expanded and folded and used to
filter out food particles as well as gas filter out food particles as well as gas exchangeexchange
Strong muscles are used to close the Strong muscles are used to close the valvesvalves
ClamsClams
Giant ClamGiant Clam
MusselsMussels OystersOysters
ScallopsScallops
ArthropodaArthropoda
ArthropodsArthropods
Arthropoda = Arthropoda = jointed footjointed foot Largest phylum Largest phylum Includes insects, spiders, centipedes, Includes insects, spiders, centipedes,
millipedes and crustaceansmillipedes and crustaceans Inhabit almost every environment on EarthInhabit almost every environment on Earth
Arthropod Characteristics Arthropod Characteristics
Segmented BodySegmented Body Bilateral symmetryBilateral symmetry Jointed appendagesJointed appendages: mouth parts and legs: mouth parts and legs Compound eyesCompound eyes ExoskeletonExoskeleton: hard, chitonous external : hard, chitonous external
skeletonskeleton Limits growthLimits growth Must Must moltmolt
ClassificationClassification
Biology of ArthropodsBiology of Arthropods
FeedingFeeding Can be parasitic, filter feeders, or detrivoresCan be parasitic, filter feeders, or detrivores
RespirationRespiration Do Not have LungsDo Not have Lungs Tracheal TubesTracheal Tubes – extend through body – extend through body Air transferred through Air transferred through SpiraclesSpiracles Marine arthropods have Marine arthropods have gillsgills or or book lungsbook lungs
CirculationCirculation Have Have gangliaganglia or many hearts run along body or many hearts run along body
Subphylum Crustacea Subphylum Crustacea
The majority of The majority of marine arthropodsmarine arthropods Includes: shrimps, lobsters, crabsIncludes: shrimps, lobsters, crabs 68,000 species68,000 species
GillsGills Skeleton hardened by calcium carbonateSkeleton hardened by calcium carbonate Appendages used to swim and/or crawlAppendages used to swim and/or crawl 2 pairs of antennae = sense2 pairs of antennae = sense ““Green” gland = salt regulationGreen” gland = salt regulation Ventral Ventral nerve chordnerve chord Complete digestive systemComplete digestive system
Subphylum Subphylum Chelicerata Chelicerata All have All have pinchers pinchers
Mouthpart called Mouthpart called chelicerateschelicerates Two body sections: Abdomen & CephalothoraxTwo body sections: Abdomen & Cephalothorax Nearly all have four pair of legsNearly all have four pair of legs Include:Include:
Spiders, Horseshoe Crabs, Scorpions, TicksSpiders, Horseshoe Crabs, Scorpions, Ticks
Insecta Insecta (Insects)(Insects)
Body divided into Body divided into 3 parts3 parts: : Head, Thorax, & AbdomenHead, Thorax, & Abdomen
Three pairs of Three pairs of legs attached to the thoraxlegs attached to the thorax Have compound eyesHave compound eyes Sense taste & smellSense taste & smell Growth involves Growth involves metamorphosismetamorphosis
Eggs Eggs Nymph Nymph Adult Adult Eggs Eggs Larva Larva Pupa Pupa Adult Adult
Form Form societiessocieties: closely related animals; same : closely related animals; same speciesspecies
Subphylum Uniramia Subphylum Uniramia
InsectsInsects Have jawsHave jaws 3 pairs of legs3 pairs of legs One pair antannaeOne pair antannae Examples: Examples:
Centipedes Centipedes : 1 pair of legs per segment: 1 pair of legs per segment MillipedesMillipedes : 2 pair of legs per segment : 2 pair of legs per segment
Echinodermata
Sea Stars, Brittle Stars, Sea Urchins, Sea Cucumbers, & Crinoids
Echinoderm Characteristics Echinodermata = spiny skin Endoskeleton
Secreted within the tissues Water vascular system
Madreporite = where water enters Tube Feet
Muscular extensions of canals End in Suckers Used for attachment, locomotion, & sensing stimuli
Pentamerous symmetry = 5 part Larvae = bilateral symmetry
Behavior
Carnivorous, detritus foragers, planktonic feeders
Reproduce by Spawning & Asexually Regeneration Protection = Spiny skins and spines Predators:
Mollusks Fish Crabs and shrimps Other echinoderms
Ecology and Range
Only marine Various habitats
Intertidal zone to bottom of the deep sea trenches
Sand to coral reefs Cold and tropical seas
Classes of Echinoderms