Transcript Annelids, Arthropods, and Echinoderms

Animalia
Annelids, Arthropods, and
Echinoderms
By:
Abby Nerenhausen &
Brock Franko
Annelids
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Members of the class Polychaeta are
marine worms. Members of the class
Oligocheata are earthworms. Members of
the class Hirudinea are parasitic worms.
Reproduction occurs through an exchange of
sperm packets
Annelids
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Annelids that burrow are very
similar to the ones of the open
ocean
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Body cavity
Segmentation
Organ system
Bristles
Move by using…
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External bristles called satae
satae fleshy appendeges calles
parapodia
Annelid- Latin word for anus
meaning “ring”
Organ System
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Cephalization
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Ganglia & Nerve Chords
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Led to the development of the
brain
Make movement of segments
of annelids possible
Majority of Annelids have
closed Circulatory System
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Moves Blood Faster
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Annelids don't have actual
hearts
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Enlarged Blood vessels serves
as heart
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Under greater pressure
Ex. Earth worms
Also do not have lungs or gills
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12000 Know species
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Close to 8000 species of polychaete worms
3100 species of Oligochaete (earth worms)
600 species of leeches
Range in size (1mm-3m)
Evolution of Annelids
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Evolved from the sea
Pholeychaete antecessor group
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Oligochaetes evolved from these
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Leeches evolved from these
Polychaete- marine worms
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Feed on small animals
Others burrow tunnels
Eat by pumping water through body
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Some iridescent
Have heads
Polychaete Fertilization
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Either male of female
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Usually fertilize externally
Males have no distinct sex
organs to produce sperm
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Sperm produced from cells
in males coelem
Females usually attach
eggs to rocks
Egg fertilized by sperm
released into water
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Will result in growth of
larvae
After time change to
juvenile polychaetes
Arthropods
9 important characteristics
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Jointed appendages
Segmentation
Head
Exoskeleton
Compound eyes
Spiricles
Circulation
Malpighian tubules
Wings
Arthropods
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Shed exoskeleton to grow
Signaled by hormones
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Forms back by a couple of hours
3 groups of Athropods
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Chelicerata (spiders and scorpions)
Crustace (crabs and lobsters)
Uniramia (insects and millipedes)
Arthropods
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Members of the class crustacea
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5 pairs of legs and 2 body regions
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Respiration use gills
Also chilopoda
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Many body segments with one pair of legs per segment
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Lobsters, crabs
Centipede
respiration use trachea and spiricles
Most undergo a change of metamorphis
Arachnids
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3 major orders
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Scorpions
Spiders
Mites
Of the class arachnida
Reproduction for arthropods and arachnids
are internal fertilization (sexually)
Respiration
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Use book lungs
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Hollow flat plates, that air circulates through.
Hemolymph flows through the plates and is
exchanges with carbon dioxide and oxygen
Crustaceans
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Aquatic
Group called decapods
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Greek for deka meaning 10 and pous meaning foot
Most common food source in the marine food chain
is..
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tiny copepods
Minute ostracods
Fairy shrimp
Water flees
Echinoderms
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Adult echinoderm body has no head, brain,
or complex sensing organs
4 major characteristics
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Endoskeleton
Five part radial symmetry
Water-vascular system
Coelomic circulation and respiration
Echinoderms
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5 living classes are…
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Sea stars
Feather stars and sea lillies
Brittle stars
Sea urchins and sand dollars
Sea cucumbers
Sea stars brittle stars
Reproduction