Transcript Invertebrates- Mollusks, Arthropods, Echinoderms By: Isaiah

Invertebrates- Mollusks,
Arthropods, Echinoderms
By: Isaiah Williams & Tyler Moskal
75% of all
animals are
Arthropods!!
Arthropods
Types of Arthropods
Insects
Arachnids
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Bees
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Spiders
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Ants
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Scorpions
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Beetles
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Mites
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Etc.…
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Tics
Notes on Arthropods
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Use a network of specialized cells (neurons) that serve as an info highway
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Dorsal brain linked to a ventral nerve cord
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One way digestive system but can vary
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Hemocell provides body with oxygen and helps dispose of CO2
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Have book lungs and tracheas (lungs)
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Some have exoskeleton while others have endoskeletons
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Reproduce sexually
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Bilateral symmetry
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Bands of muscle tissues allow them to move
Insects
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Exoskeleton made of chitin
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3 part body (head, thorax, abdomen)
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3 pairs of jointed legs
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Compound eyes and 1 antennae
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Takes up more than half of animal population (Most diverse)
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Can live anywhere
Continued
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More than 1 million species
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Hatch from eggs/larvae (also molt later on in life)
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Undergo some type of metamorphosis
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Can have wings, gills, and water striders
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Can also live in colonies
Arachnids
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Joint-legged
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8 legs (4 pairs)
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Body divided into 2 (tagmata: cephalothorax, abdomen)
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Don’t have wings or antennae's
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Lack enteson muscles
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Spiders & Scorpions use limbs hydraulically using pressure of their
hemolymph
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Use chelicerae for feeding and defense (appendage)
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Use pedipalps for feeding, locomotion and reproductive functions
(appendage)
Types of Arthropods
Crustaceans
Centipedes/Millipedes
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Crabs
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Madagascar centipede
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Shrimp
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North American millipede
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Barnacles
Crustaceans
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Biramous-2 parted limbs
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Nauplius- form of larvae
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Both aquatic and terrestrial
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Some are parasitic and sessile
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Shell can be divided into a dorsal tergum, ventral sternum,
and lateral pleuron
Continued
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Open circulatory system
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Gizzard like organ called gastric mill
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Antennae, mandibles, and maxillae
Millipedes & Centipedes
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2 pairs of legs on each body
segment
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Elongated metameric shape
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20-300 legs
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Odd # of pairs of legs (Always)
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Carnivorous
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2 single segments (fused together)
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Elongated, cylindrical, or flattened
bodies
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34-750 legs
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Venom fangs called forcipules
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12,000 species
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8,000 species
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Detritivores
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DON’T bite (secrete foul smelling
chemical)
Some can be very toxic and
sometimes lethal
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DO bite
Skeletal System
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Exoskeleton provides the organism with a lot of space for
movement (joints, anchor for muscles and appendages)
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Provides protection from the outside world
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Hard outer shell composed of chitin
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Other species exoskeletons are composed of lipids,
proteins, and calcium carbonate
Reproductive system
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Separate sexes (male and female)
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The gonads (paired sex organs) are connected directly to ducts
that are located on the ventral surface of the trunk (exact
location depends on species)
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Sperm is transferred to female within seal packets called
spermatophores.
Mollusk
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112,000 different species
Some are sedentary filter feeders
Some are fast moving predators
Have a true Coelom
Oldest fossil was 500 million years old
Notes on Mollusks
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Bilateral symmetry
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Move using their muscular foot, and tentacles
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Nervous system: nerve bundles (ganglia)
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Squids have eyes similar to humans
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One way digestive system (siphon system)
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Cephalopods: closed, Gastropods: open (circulatory system)
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Have gills (siphons) respiratory system
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Reproduce sexually using gonads
Mollusk
Types of Mollusks
Cephalopods
Gastropods
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Squid
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Snails
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Cuttlefish
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Slugs
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Octopus
Class Gastropod
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9000 species
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Snails, abalones, conch
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Have a single cell
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Undergo a process know as “torsion” during larval
development.
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Can retreat its head into its mantle cavity when threatned.
Class Cephalopods
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Bilateral, Body symmetry
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Prominent head, set of arms or tentacles and Mollusca foot.
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800 species
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Most complex brains of invertebrates
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Brains protected by cartilaginous cranium
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Have beaks
continue
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Social creatures
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Advanced vision
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Can detect water density
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Can camouflage themselves
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Release ink when in danger
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2 gill hearts that move blood through capillaries
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Move using jet propultion
Cuttlefish
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Live about 2 years
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W-Shaped pupils
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Eight arms
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2 tentacles
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One of the largest brains of all invertebrates
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One of the most intelligent invertebrates
Snails & Slugs
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Coiled shell
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Can retreat into its shell for protection
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Coated in a mucus that help them move and for protection
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Don’t require large amounts of food
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Can live in both water and on land
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Can carry parasites
Clams
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Both freshwater and marine
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Can weigh up to 340 lbs
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Can live up to over 500 years old
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Do not have heads and are blind
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Filter feeders
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2 calcareous shells or valves
Echinoderms
Echinoderms
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Radial symmetry
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Star fish, sea urchins, sand dollars, sea cucumber, sea lilies
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Can be found in every ocean depth
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Can regenerate tissues, organs, and limbs
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Undergoes metamorphosis
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7000 species
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Mostly found in benthic zone
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Use water vascular system
Notes on Echinoderms
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Radial symmetry
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Move using tube feet (each arm has hundreds of tubes)
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Also use water vascular system to aid in movement
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Suckers to navigate
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Nervous system: sensory cells, nerve ring, & eye spots detect light
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One way digestive system (digest externally), push stomach
outside body
Continued
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Excretory system: water vascular system (no kidneys)
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Use diffusion/osmosis for circulatory system
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Open circulatory system
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No true hearts
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Cilia circulates fluids
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Fluid filled canals for gas exchange
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Diffusion/osmosis for respiratory system (water vascular system)
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Endoskeleton for skeletal support (covered by epidermis)
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Reproduce sexually using spermatofors
Sea Star
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1500 species
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Live in every ocean
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Can live in abyssal depths
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Have a central discs and 5 arms
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Can be smooth, ridged, or spiny
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Tube feet operated by a hydraulic system
Sea cucumber
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Leathery skin and a elongated body
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Found on the sea floor worldwide
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1717 species know
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Very common in Asia
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Help recycle nutrients
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Have a endoskeleton
Sea Urchin
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950 species
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Spines used for protection
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Can live 5000 meters deep
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3 to 10 centimeters
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Feed mostly on algae
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Sea (Hedgehogs)
YouTube Videos
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https://www.youtube.com/watch?v=2bBHKHhgjeM
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https://www.youtube.com/watch?v=GsF_pt18krk
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https://www.youtube.com/watch?v=qIhCyJxxOho
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https://www.youtube.com/watch?v=DIjGrR8FaJA
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https://www.youtube.com/watch?v=6mUjCa_LmiQ
Interactive Activities
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http://tolweb.org/treehouses/?treehouse_id=3923
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http://kr021.k12.sd.us/review.htm
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Play mollusk jeopardy
Play echinoderm jeopardy #1
Play arthropod jeopardy #1
http://www.sheppardsoftware.com/content/animals/profile_
mollusks.htm
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Take mollusk quiz on top lefts side of site
Work Cited
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http://www.snail-world.com/
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http://www.nationalgeographic.com/
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https://www.youtube.com/
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http://www.animalplanet.com/
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http://en.wikipedia.org/
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http://www.enchantedlearning.com/subjects/invertebrates/bi
valve/Clamprintout.shtml