Download L8: Animal Diversity

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Animal Phylogeny
Animal Diversity
Lecture 8
Winter 2014
Fig. 32.10
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Phylum Porifera (sponges)
3a
Phylum Cnidaria
(corals, jellies, hydras, sea anemones)
~ 10,000 species
• Primarily marine
• Feed by using
tentacles with stinging
cells (cnidocytes) to
capture prey
Traits
• True tissues
• Radial symmetry
• Gastrovascular cavity
• Diploblast
~5,500 species
• Primarily marine
• Suspension feeders
Traits
• No true tissues
• No plane of symmetry
• Sessile (attached)
Fig. 33.4
3b
Phylum Cnidaria
(corals, jellies, hydras, sea anemones)
See Fig. 33.5
Fig. 33.6
Phylum Platyhelminthes (flatworms)
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(Clade Lophotrochozoa)
• ~ 20,000 species
• Marine, freshwater & moist
terrestrial
• Free-living & parasitic
• Feeds by sucking food into
mouth with muscular tube
Traits
• True tissue
Fig. 33.12
• Bilateral symmetry
• Gastrovascular cavity
• Triploblast
• Acoelomate
Fig. 33.10
Fig. 33.8
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Phylum Mollusca (molluscs)
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Phylum Annelida (segmented worms)
(Clade Lophotrochozoa)
• ~93,000 species
• e.g., slugs, snails, squid,
octopus, oysters
• Most marine, some
freshwater and
terrestrial
• Use radula (scraping
tongue) to feed
Traits
• True tissue
• Bilateral symmetry
• Complete digestive tract
• Triploblast
• True coelom (coelomate)
• Soft body with hard shell
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(Clade Lophotrochozoa)
Fig. 33.15
~ 16,500 species
• Earthworms, polychaetes,
leeches
• Marine, freshwater &
damp terrestrial
Traits
• True tissue
• Bilateral symmetry
• Complete digestive tract
• Triploblast
• True coelom (coelomate)
• Segmented body plan
• Earthworms eat by
swallowing soil
• Polychaetes & leeches
eat small invertebrates
(few suck blood)
– Some have reduced shell or lost shell
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Phylum Nematoda (Roundworms)
Phylum Arthropoda (Arthropods)
(Clade Ecdysozoa)
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(Clade Ecdysozoa)
• ~25,000 species
• Decomposers
• Also called nematodes
• Also parasites
• Soil and aquatic habitats
– Pinworm, hookworm
Traits
• Agricultural pests
• True tissue
• Bilateral symmetry
Fig. 33.25
• Complete digestive tract
• Triploblast
• Pseudocoelom
• Tough cuticle coating body
• > 1 million species
• Widespread
• Huge population numbers
Traits
• True tissue
• Bilateral symmetry
• Complete digestive tract
• Triploblast
• True coelom (coelomate)
– Often reduced in adults
• Segmented body plan
– Tagmatization
• Jointed appendages
• Exoskeleton
Fig. 33.25
– chitin (polysaccharide)
Fig. 33.26
Class Arachnida (spiders, mites, ticks, scorpions)
& Class Merostomata (horseshoe crabs) 9
(Subphylum Cheliceriformes)
• Body having one or two main
parts (cephalothorax,
abdomen)
• 4 pairs of walking legs
• Lacks mandibles
• Has pincers or fangs
(chelicerae)
• No antennae
• Simple eyes (most)
Fig. 33.30
Class Insecta (insects)
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(Subphylum Hexapoda )
• Species rich & abundant!
– Over ½ of named species on earth
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Fig. 33.31
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Flight
Metamorphosis
Diverse habitats (rarely marine)
Body divided into head, thorax,
abdomen
1 pair of antennae
Uniramous appendages
Mouthparts adapted for many uses
3 pair of walking legs
~ 2 pair of wings
Compound eyes
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Class Chilopoda (centipedes) &
Class Diplopoda (millipedes)
(Subphylum Myriapoda)
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(Subphylum Crustacea)
Fig. 33.34 - Centipede
1 pair of antennae
Mandibles
Uniramous appendages
Terrestrial
Class Chilopoda (centipedes)
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Class Malacostraca (crabs, lobsters, shrimps) &
Class Maxillopoda (barnacles, copopods)
– One set of legs per body segment
– Poison claws on first body segment
– Carnivorous
• Class Diplopoda (milipedes)
– Two sets of legs per body segment
– Herbivorous
• Marine & freshwater
• Body of two or three parts
• ~Highly specialized
appendages
• Biramous appendages
• Mandibles
• Two pair of antennae
• Three or more pairs of
legs
• Pair of compound eyes
Fig. 33.38
Fig. 33.25
Fig. 33.33 - Millipede
Phylum Echinodermata (Echinoderms)
• ~7,000 species
• Sea stars, sea urchins, sea
cucumbers, sand dollars
Traits
• True tissue
• Apparent radial symmetry (as
adults)
• Bilateral symmetry (larval form)
• Complete digestive tract
• Triploblast
• True coelom (coelomate)
• Deuterostome
• No body segmentation
• Endoskeleton
• Water vascular system
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• Marine
• Sessile or slow moving
• Named for spiny
surfaces
• Most closely related
phylum to the chordates
~ 52,000 species
Traits present in embryo
(sometime in adult)
Traits can be greatly
reduced or not present in
adults
Traits
• Dorsal, hollow nerve cord
• Notochord
Other traits
• True tissue
• Bilateral symmetry
• Complete digestive tract
• True coelom (coelomate)
• Body segmentation
• Deuterostome
– Flexible rod located
between nerve cord and
digestive tract
• Pharyngeal pouches
(slits)
– Gill structures
– Network of water filled canals, for
gas exchange, waste disposal, and
movement
• Post-anal tail
– Tail is to rear of anus
Phylum Chordata (Chordates)
Three subphylum
• Cephalochordata
– Lancelets
• Urochordata
– tunicates
• Vertebrata
Vetebrata Trait
• Vertebrae
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Phylum Chordata (Chordates)
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Fig. 34.3
Subphylum Cephalochordata
(Lancelets)
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• Marine environment
Traits
• Dorsal, hollow nerve cord
• Notochord
– Extends to front of head
• Pharyngeal slits
• Post-anal tail
Fig. 34.2
Fig. 34.4
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Subphylum Urochordata (tunicates)
• Marine
• Filter feeder
• Chordate characteristics present in larval stage,
most lost as adult
Subphylum Vertebrata
Class Cephalaspidomorphi (Petromyzontida)
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• Lampreys
• ~25 species
• Marine & Freshwater
Traits
• No jaws
• Parasitic (most)
• Skeleton of cartilage
– Made of protein matrix
(not collagen)
• External gill slits
Fig. 34.10
Fig. 34.5
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Subphylum Vertebrata:
Class Chondrichthyes
– skeletons reinforced with calcium
phosphate
– Derived condition
– Mostly collegen matrix
• Operculum
Fig. 34.17
– Protective flap over gill slits
• Some with calcium
• Swim bladder
– Buoyancy
– evolved from early lungs
• Fins supported by bony rays
Fig. 34.15
Subphylum Vertebrata: Class Sarcopterygii
Superclass Osteichthyes
• Lobe-finned fish
• Coelacanth, lungfish
Traits
• Ossified (bony) skeleton
• Lungs or lung derivatives
• Operculum
• Swim bladder
• Pectoral & pelvic fins have
rod-shaped bones
surrounded by thick layer of
muscle
– “walk” underwater
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• Ray-finned fish
• ~27,000 species
Traits
• Ossified (bony) skeleton
• Sharks, skates & rays
• ~750 species
Traits
• Skeleton of cartilage
• Jaws
• External gill slits
• No swim bladder
Subphylum Vertebrata: Class Actinopterygii
Superclass Osteichthyes
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Subphylum Vertebrata: Class Amphibia
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• ~6150 species
• Frogs, salamanders
• Moist environments
Fig. 34.18: Coelacanth
Lungfish
– Egg has no shell, needs to be
kept from drying out
– Skin acts in gas exchange,
needs to be moist
• Many undergo
metamorphosis
Traits
• Tetrapods (four limbs)
• Adults have lungs
See Fig. 34.22
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Subphylum Vertebrata:
Class Reptilia
• ~17,900 species of snakes,
lizards, turtles, crocodiles,
alligators, and birds
Traits
• Tetrapods
• Ectotherms (except birds!)
• Amniotic egg (amniotes)
See figure 34.27
Subphylum Vertebrata:
Class Reptilia (Superorder Lepidosauria)
Lizards, Snakes and Tuataras
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• ~7,900 species of snakes, lizards,
turtles
• Traits
• Tetrapods
• Amniotic egg (amniotes)
See figure 34.30
– Fluid filled egg in protective
shell
– Water proof skin
– Fluid filled egg in protective
shell
– Water proof skin
• Scales with keratin
• Ecototherms
• Scales with keratin
– Keratin also in feathers, fingernails
– Do not generate their own heat, use
heat from their environment
See Fig. 34.27
Subphylum Vertebrata:
Class Reptilia (Superorder Archosauria)
Birds, Crocodiles, and Alligators
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• ~10,000 species birds
– 23 species alligators and crocodiles
See figure 34.30
• Birds descended from lineage of dinosaurs that
had feathers
– Crocodiles and Alligators are closest living
relatives to birds
Traits:
• Tetrapods
• Amniotic egg (amniotes)
• Wings - Feathers of keratin
Bird Adaptations for flight
• Hollow bones
• No teeth
• Large sternum and strong pectoral muscles
• Reduced organs or missing organs
• Endotherms – Birds only!
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• 307 known species of species of
turtles
• Traits
• Tetrapods
• Amniotic egg (amniotes)
– Fluid filled egg in protective
shell
– Water proof skin
• Scales with keratin
• Vertebral column fused to shell
• Terrestrial or aquatic (both marine
and fresh water)
• Ecototherms
– High metabolic rate – use heat produced to
maintain constant body temperatures!
Subphylum Vertebrata: Class Mammalia
Subphylum Vertebrata:
Class Reptilia (Order Testudines) Turtles
– Do not generate their own heat, use
heat from their environment
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~5,300 species
Rapid diversification ~ 65 myo (end of “age
of the reptiles”)
Traits
• Tetrapods
• Amniotic egg (most w/o shell)
• Hair
• Mammary glands
• Endotherms
Three main group
• Monotremes (egg laying mammals)
– Only 2 species (duck-billed platypus, echidna)
• Marsupials (“pouched” mammals)
– Offspring complete their development in pouches
– Primarily Australia & South America
• Eutherians (placental mammals)
– Offspring remain in womb
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