- "claw"
- Horseshoe crabs, spiders, mites, ticks
- Some of first terrestrial animals
- A. Two segments/ tagmata
- Cephalothorax (sensory, NO antennae or mandibles)
- Abdomen (dig, rep, excre, resp)
- B. Chelicerae
- First pair of appendages
- Pincerlike- may be fangs
- C. Pedipalps
- Second pair of appendages
- Handle food and transfer sperm
- Followed by 4 pairs of walking legs
- 75% of all iving species, diverse, 26 orders
- 1. Adaptations for terresttrial existence
- Exoskeleton
- Flight
- Water conserving systems
- Desiccation resistant eggs, internal fertilization
- Metamorphosis
- Diverse mouthparts and feeding habits
- 2. Characteristics
- 3 tagmata- head, thorax, abdomen
- 1 pair antennae1 pair compound eyes
- Mandibles/ mouthparts
- 3 pairs legs
- 2 pairs wings
- Only invertebrates that fly
- 3. Digestion
- Specialized enzymes
- 4. Malpighian tubules
- For excretion, energy expensive
- 5. Tracheae
- Chitin-lined tubules with external spiracles
- 6. Dioecious with internal fertilization
- Parental care in some groups
- 7. Metamorphosis
- Abrupt transition from larval to adult forms
- Hormonally controlled
- Complete and incomplete
- 2 invertebrate subphyla, 1 vertebte subphylum
- A. Notochrod
- Dorsal hollow rod that extends the length of the body and serves as a firm but flexible axis
- B. Dorsal tubular nerve chord
- forms CNS
- C. Pharyngeal Pouches
- Openings in the lining of the upper respiratory tract
- Form gills in fish and amphibian larvae
- D. Postanal tail
- Tail that continues past end of digestive tract )anus)
- A. Ectothermy- "cold blooded"
- Metabolism is not used to control body temperature
- B. Gas exchange- gills
- Evaginations of body surface
- (1) Ventilate using mouth and operculum (or spiracle/ swimming)
- (2) Counter-current exchange-
- Allows uptake of more oxygen from water
- Water flows opposite direction to blood flow through gills
- C. Circulation
- (1) single-loop circulatory pathway
- (2) 2-chamber heart pumps blood to gills --> body
- D. Excretion and Osmoregulation
- (1)Kidneys excrete ammonia as nitrogenous wase product
- Very toxic
- Requires a lot of water to excrete
- (2) Osmoregulation
- Cartilaginous fish- isotonic to surroundings due to urea in tissues
- Marine bony fish- hypotonic to surroundings
- Drink water continuously, actively transport salt out across gills
- Freshwater bony fish- hypertonic to surroundings
- never drink water, actively transport salt across gills
- Large amts of urine produced
- 3900 species; frogs, toads, salamanders, caecilians
- A. First tetrapods- 4 limbs
- Age of amphibians
- Carbonfiderous period 345 mya
- B. 2 skeletal girdles with stocky limbs attached- 5 digits
- C. Gas exchange- cutaneous (through moist skin)
- Gills as larvae, lungs as adults
- Positive pressure breathing
- D. External fertilization (some internal)
- Oviparous
- E. Reproduce in aquatic environment
- Photo on phone
- F. Ectothermic
- Do not use metabolism to regulate body temperature
- Can't survive in environments with temperature fluctuations
- Torpor- state of reduced activity
- G. Circulation
- Double-loop circulatory pathway
- 3-chamber heart pumps blood to lungs & skin, back to heart, and then to systemic (body) capillaries
- H. Excretion
- Larval amphibians excrete ammonia
- Adult amphibians excrete urea
- Urea is less toxic and can be excreted in concentration form
- I. Adaptations for terrestrial life
- Skin glands and coloration
- Noctornal
- SPecialized tongue
- Long hind limbs for jumping
- J. Evolved from ancestors resembling early lobe finned fishes
- 9100 species
- A. scales and amniotic eggs
- B. Feathers- modified scales (keratin)
- Contour-flight
- Down- insulation
- Other functions:
- Species recognition, waterproofing, sensory perception
- C. Endothermic
- Use own metabolic enegy to maintain temperature
- Very energy expensive, but great selective advantage
- D. Modified skeleton
- Enlarged sternum with keel
- Porous bones
- Horny beak (no teeth)
- E. Well-developed nervous system
- Acute vision (best of all vertebrates)
- Seasonal migration
- Elaborate courtship displays
- Vocalizations
- Parental care/ nesting
- F. Internal fertilization
- Oviparous
- G. Circulation
- 4-chambered heart
- Double-loop circulation
- H. Excretion
- Excrete uric acid from cloaca
- I. Digestive adaptations
- Gizzard
- Long tongue (woodpeckers/ hummingbirds)
- Curved beak and sharp talons (carnivorous birds)
- J. Gas exchange
- Anterior and posterior air sacs
- One-way air flow (no mixing of fresh air with old air)
- Remove 90% of oxygen from air
Animal Kingdom Flowchart
Ancestral Protist
Metazoa
Porifera (Sponges)
(Triploblastic)
- No true tissues, or parazoa
- "pore bearer"
- Habitat is mainly marine in shallow coastal waters, some freshwater
- There are exceptions like the tree sponge in Venezuela that can remain dormant out of water
- As an adult, it is attached to a substrate= sessile
- As larvae they are motile
- Have a water filtering system made up of a few cell types
- Choanocytes are collar cells used for filter feeding
- Amoebocytes are essential for reproduction, they form spicules and help with feeding
- Skeletons are composed of crystalline spicuoles composed of:
- CaCO3 or silica
- All sponges contain the protein spongin
- They can be asexual
- Budding (regeneration)
- No genetic variation
- They can also be sexual
- Choanoctypes/ amoebocytes
- They are monoecious/ hermaphrodites
- Same individual has both male and female reproductive structure
(Diploblastic)
Ctenophora
Cnidarians
- Comb jellies
- 90 Species
- Habitat
- Warm marine
- Motility
- 8 comblike plates of fused cilia
- Bioluminescent: capable of producing light
- "nettle"
- 9000 species
- Jelly fish, sea anemones, hydra, corals
- Habitat
- Live in mainly marine, shallow coastal water, sometimes freshwater, sometimes deep water
- Digestion
- They have a gastrovasualr cavity
- One opening serves as both a mouth and an anus
- Cavity lining secretes digestive enzymes
- They are dimorphic, possessing two body forms:
Polyp
Medusa
- Tentacles with cnidocytes
- Cells used for defense and capturing prey
- Stinging capsules called nematocysts "thread bag"
- They have a simple nervous system
- Nerve net: transmission in several directions
- Reproduction
- Most are dioecious (separate sexes)
- Some are asexual and reproduce with budding
Nemertea
Platyhelminthes
Nematoda
Rotifera
- "flat worms"
- 13,000 species
- Lophotrochozoa general characteristics
- Digestion
- Gastrovascular cavity (incomplete)
- Habitat
- Variety,
- Hermaphroditic
- Nervous system
- Anterior ganglia and longitudinal nerve cords
- Three Classes:
Cestoda
- General Characteristics
- Roundworms, 90,000 species
- Probably most abundant multicellular animal
- Ecdysozoan "ecdysis"- molting
- Shed cuticle
- Pseudocoelom
- Range in size from microscopic to several meters
- Complete digestive tract
- 1 way, mouth to anus, tube within a tube
- Cylindrical, unsegmented with longitudinal muscles
- .......
- ......
Trematoda
Turbellaria
- "wheel to bear"
- 2000 species
- Lophotrochozoan general characteristics
- Corona
- "Crown"
- Ciliated organ motility and feeding
- Pseudocoelom
- Has endoderm on one side and mezoderm on other side
- Mainly freshwater, some in sediments
- Small, 1000 cells, some colonial
- Reproduce sexually and by parthenogensis
- Virgin production, development of gamete without fertilization
- Resurrection Animacules
- Desiccate during harsh conditions and go dormant
Paraditic Nematodes
Mollusca
- "Commotion-like"
- 300 species
- Freshwater carnivores
- Regeneration
- Flame cells (osmoregulation)
- "Girdle form"
- Tapeworms
- 3500 species
- Unique adaptions for parasitism
- Tough, outer layer of cells resistant to host body fluids
- Scolex- hooks/ suckers on anterior end (attach to host intestine)
- No mouth, no digestive cavity and no digestive enzymes (absorb nutrients across body wall)
- Proglottids- reproductive unit that produce eggs
- Originated from free0living forms can reach lengths of 20 meters (60 ft)
- "perforated form"
- Flukes
- 11,000 species
- Almost all parasitic with 2 or more hosts (primary and secondary)
- Schistosoma (split body)
- Blood fluke
- Chinese Liver Fluke
Cephalopoda
Gastropoda
- Ascaris
- Intestinal parasite of humas and other vertebrates
- Transmitted in fecal matter
- Estimated 25% of world's population infected
- Pinworms
- Most common roundworm in US
- 10% of humans infected, lower region of colon
- Hookworm
- Common in Souther US
- Worms penetrate skin, found in small intestine
- Trichinella
- Encysts in skeletal muscle of human and pigs
- Trichinosis
- Filarial Worms
- Commonly found in tropical regions
- Some block vessels of lymphatic system = elephantiasis (transmitted by mosquitos)
- Heart worms (transmitted by mosquito)
Echinodermata
- "gut foot"
- 35,000 species
- Snails, slugs, abalones, limpets, nudibranchs
- 1. Largest and most varied class
- 2. Habitat- marine, freshwater, terrestrial
- 3. Torsion
- 180 degree countercloclwise twisting of visceral mass, mantle, and mantle cavity
- 4. Foot used for motility
- 5. Monoecious/ dioecious/ protandrid (testes then ovaries)
- "head-foot"
- Squid, octopus, cuttlefish
- 1. Most complex, evolutionary advanced mollusks; "primates of the sea" (well-developed sense organs"
- 2. Habitat
- Marine (lost shell, or interalized, more mobility)
- 3. Jet Propulsion
- water in mantle cavity is forced out siphon
- 4. Foot modified into tentacles and arms around head and beak
- Chemoreceptors on suckers for detecting food
- 5. Ink sacs and chromatophores
- release dark fluids/ change color with pigments cells
- 6. Closed circulatory system
- Blood contained in vessels with 3 hearts
- 7. Dioecious
- 110,000 species
- Snails, slugs, clams, oyster, squid, octopus, cuttlefish
- Lophotrochozoan general characteristics
- First animals to develop hard external covering
- Shell of CaCO3
- 1. Discourages predators
- 2. Enable colonization of land
- Common features to all mollusks
- Visceral mass- organs of digestion, reproduction, circulation and excretion
- Foot- muscular organ
- Locomotion, attachment to substrate, food capture
- Mantle
- Lies on either side of visceral mass; secretes shell
- **Radula (not in all mollusks)
- Rasping structure with rows of teeth
- Used for feeding (not in bivalves)
- Open circulatory system- no small vessels
- Nervous system
- Ganglia connected by nerve chords
- Metanephridia- excretory organs
Bivalvia
Trochophores
- "two leaf" 30,000 species
- Clams, oysters, scallops, mussels
- 1. 2 shells or valves, strong adductor muscles, no radula or head
- 2. Mainly aquatic- burrow in substrate
- 3. Filter feeders- "miner's canary"
- 4. Highly muscular foot- for digging and attachment
- 5. Mainly dioecious (separate sexes)
Polyplacophora
- 6,000 species
- Sea stars, sea urchins, sand dollars, sea cucumbers, sea lilies
- Sessile or sedentary with pentaradial symmetry
- Endoskeleton
- Internal skeleton (calcium plates)
- Water vascular system
- Network of hydraulic canals attached to tube feet
- (motility, gas exchange, feeding, attachment)
- Digestive and reproductive glands in each arm
- Gas excahnge via gills on skin
- Separate sexes with external fertilization
- Regeneration
- Phylogeny
- Share common ancestry with Chordata
- Evolved around 600 mya from bilaterally...
- 1. Ancient mollusks
- "Many plates to bear", chitons
- Resemble Cambrian ancestors
- 2. 8 articulating valves
- 3. slow moving herbivores, used radula to scrape algae
- 4. Dioecious
Class Amphibia
Trochophores
Chordata
Annelida
Arthropoda
Polychaeta
- "many hair", 8000 species
- 1. Habitat
- Mainly marine, burrowing, coral reefs, mucus tubes
- 2. Parapodia
- "beside, or almost foot"
- Gas exchange and motility (bundles of setae)
- 3. Nutrition
- Filter feeders, scavengers, carnivores, herbivores
- Open circulatory system
- Pumps blood into hemocoel (tissue spaces)
- Metamorphosis often present
- Reduces competition between immature and adult states
- Variety of gas exchange organs
- Gills
- Booklungs
- Tracheae
Oligochaeta
- "few hair" 3100 species
- 1. Habitat
- Terrestrial, freshwater, and marine
- 2. Gas exchange across a body wall
- 3. Beneficial to agriculture
- break up, enrich, and aerate soil by burrowing
- Form castings, 15 tons soil/acre/year
- Vegetation shredders- increases surface area
- General Lophotrochozoan
- Metameric body
- rings externally, septa internally
- 1. Each segment controlled independently
- 2. Lessens impact of injury
- 3. Allos specialization of body parts for specific functions = tagmatization
- Setae- bristles (help anchor worm)
- Hydrostatic skeleton- from coelom (tube within a tube)
- Circular and longitudinal muscles
- Specialized 1-way digestive tract
- Pharynx --> esophagus --> crop --> gizzard --> intestine --> anus
- Nervous system
- Brain with ventral solid nerve chord
- Ganglion in each segment
- Excretory system
- 1 pair of nephridia per segment
- Asexual/ sexual reproduction
- Monoecious/ dioecious
- Ecdysozoan, "jointed foot"
- 1 million species (3/4 described species)
- Ver diverse, most successful animals, greatest # of species
- Segmented body with specialization of body regiobs for specific functions (tagmatization)
- Head, thoax, abdomen (tagmata)
- Exoskeleton- composed of chitin (polysaccharide)
- 1. Prevents water loss
- 2. Protection
- 3. Support
- 4. Muscle attachment
- *Shed at intervals (molting or ecdysis)
- Major energy expenditure
- Vulnerable
- Paired, jointed appendages
- Legs, antennae, mouthparts
- Well-developed nervous system
- Brain and ventral chord
- Functions at local level
- Compound and simple eye
Hirudinae
- Leeches
- 1. Habitat
- Freshwater, terrestrial, marine
- 2. Prey on small invertebrates or vertebrate body fluids
- 3. Anterior and posterior suckers
- Secrete hirudin (powerful anticoagulant)
- Prevents blood from clotting
- 4. Used in medicinal practices
Trochophores
Vertebrates
Invertebrates
Origin of Vertebrates
- A. Evolved during Cambrian period (550 mya) from protovertebrate (possibly urochordate larva)
- B. Natural selection may have reinforced paedogenesis development of sexual maturity in larval form
- *Milestone in vertebrate evolution
Vertebrate Characteristics
- Retain all characteristics as embryos
- A. Notochd is replaced by vertebral column = vertebrae
- B. Skull/ Cranium- encloses and protects brain (high degree of cephalization with complex sense organs)
- C. Jointed endoskeleton- bone or cartilage, protection and muscle attachment, huge support role
- D. Closed cirulatory system and efficient gas exchange
- Large coelom and complete digestive tract
- E. Kidney- excretion (nitrogenous wastes) and osmoregulation (water and salt balance)
- F. Dioecious- sexual reproduction
- Internal/ external fertilization
- G. 6 extant classes + 1 extinct class
- 4 fish
- Agnatha
- Placodermi (extinct)
- Chondrichthyes
- Osteichthyes
- 3 Tetrapods
- Amphibia
- Reptilia (including bird-like reptiles)
- Mammalia
Subphylum Crustacea
Subphylum Uniramia
Class Hexapoda
Subphylum Urochordata
No Jaws
Jaws
Classes: Gastropoda, Bivalvia
Superclass Agnathan
- "hard-shelled" (CaCO3 in exoskeleton)
- Crayfish, lobsters
- A. Habitat
- All aquatic except soem crabs and isopods
- B. Two segments
- Cephalothorax (carapace) and abdomen
- C. Jointed appendages:
- Two pair of antennae
- Jawlike mandibles
- Maxillae- food handling
- 5 pairs of walking legs- 1st pair claws or chelipeds
- Swimmerets
- Powerful tail
- D. Regenerate legs or claws
- Autotomy- "self cut"
- E. Feed on dead, decaying organisms, invertebrates, plants
Subphylum Chelicerata
Subphylum Trilobitomorpha
- Tunicates (sea squirts)
- Possess all chordate characteristics as larvae
- Adult only have pharyngeal gill slits
- Sessile filter feeders
- 2 siphons, touch tunic
- A. Lack jaws and paired appendages
- B. Cartilaginous skeletons (notochord present)
- C. Ostracoderms were some of the first jawless fishes
- Armor of bony plates
- Filter feeders
- D. Jawless fishes declined and disappeared during the Devonian (400 mya) only 60 species exist today
- (1) Hagfish- marine scavengers (most primitive vertebrates)
- (2) Lampreys- eel-like parasites, raspig tongue and teeth alternate between lakes/ocean and freshwater streams
- "one lobe"
- Insects, centipedes, millipedes
Superclass Myriapoda
no teeth
teeth
Class Diplopoda
- "three lobes"
- Best known Cambrian period fossils
- Now extinct (600 mya-345 mya)
- Speedy, agility, keen vision
- Successful, bottom dwellers
- Left a good indention on fossil record due to their abundance
Insects and Humans
- "thousand leggers"
- Millipedes
- 1-2 pairs legs/body segment
- Cylindrical, worm-like body
- Habitat- damp terrestrial environments
- Herbivores
Subphylum Cephalochrodata
Placodermi
- Only 0.5% insects adversely influence human health
- Pollinations of apprx 65% plant species
- Biological control
- Nutrient cycling
- Food webs
- Insect damage to US crops
Class Chilopoda
- "hundred leggers" centipedes
- 1 pair legs/body segment
- (1st pair modified into fangs with poison glands)
- Body elongated and flattened
- Habitat- damp terrestrial environments
no lungs
lungs
- A. Class Placodermi "platelike armor, skin"
- Replaced agnathans
- First appeared 400 mya
- (1) Paired fins- enhanced swimming
- (2) Hinged jaws-developed from anterior gill support rods/ arches
- **Paired fins and hinged jaws allowed for fish diversification; enhanced fitness of species, active predation
- (3) Disappered
- Lancelets, Amphioxus
- 1. Marine filter feeders, resemble fish
- 2. Burrow into sand with head exposed
- 3. Retain all chrodate characeristics as adult
- 4. Segmented muscles in tail...
Class Arachnida
Chondrichthyes
4 limbs
not 4 limbs
Osteichthyes
B. Class Chondrichthyes- "cartilage fish" 850 species, sharks, skates, rays
(1) Cartilaginous skeleton
(2) Aquatic habitat- majority marine
(3) Jaws and 2 sets of paired fins
(4) Dermal, placoid scales- posteriorly pointed
(5) Sense electric currents
Keen sense of smell
Lateral line system- sense pressure
(6) Oviparous, viviparous (uterus, live birth), Ovoviviparous (uterus, eggs in womb, born live)
General Fish Characteristics
- D. Predatory- live on liquid diet
- Secrete enzymes on prey to digest, suck up liquid
- E. Book lungs
- Gas exchange
- Prevent water loss
- F. Malpighian Tubules
- Excretory organs
- Concentrate wastes as uric acid (dry crystals- conserve water)
- G. Several pairs of eyes and sensory hairs
- H. Spinneretes
- Make silk (liquid protein)
- Polymerizes in air (drop lines- escaping predation)
- Egg cases , shrouds, webs, nests, dispersal
- I. Dioecious
- J. Spiders and humans
- Some beneficial
- Some venomous (black widow and brown recluse)
no amniotic egg
amniotic egg
amphibians
Orders in Amphibia
- A. Order Caudata"tail to bear"; 350 species
- Salamanders, newts
- Internal fertilization in female cloaca
- Cloaca is a common chamber to urinary, digestive and reproductive tracts
- B. Order Gymnophiona
- 160 species
- Caecillians
- Legless burrowers
- Retractable tentacles
- C. Order Anura 'without tail"
- 3500 species
- Frogs and toads
- variety of adaptations for terrestrial habitat
- Gastric brooding frog
mammary glands
mammalia
no mammary glands
Reptilia
Phylogeny
- A. "Age of Mammals" 70 mya
- Adaptive radiation following extinction of the dinosaurs
- B. First Mammals
- 300-220 mya (before birds)
- Share amniote ancestor with reptiles
- Only survivors of therapsid line
- Ex: Pelycosaur Dimetrodon
- First mammals were probably nocturnal, shrew-like
no feathers
feathers
birds
- C. Class Osteichthyes "bony fish"
- Most abundant and diverse class of vertebrates, 25,000 species
- (1) Evolved in freshwater not sea
- (2) Bony skeleton and scales (with mucus)
- (3) Paired fins-flexible --> steering and propulsion
- (4) Operculum- protective flap over gills
- (5) First bony fishes had lung in addition to gills- used as supplementary gas exchange organ
- (6) Most oviparous with external fertilization
- (7) 2 lineages of bony fish
Mammalian Characteristics
Bird Evolution
- 4800 species (17 orders)
- A. Hair
- Contains protein keratin
- Insulation
- Camouflage
- Sensory perception
- Protection
- Warning coloration
- B. Endothermic
- C. Mammary glands
- Produce milk
- Similar to scent and musk glands
- D. Internal Fertilization
- E. Well developed nervous system
- Highly intelligent with large brain
- Olfactory, visual and auditory senses
- Complex behaviors
- F. Circulatory
- 4 chambered heart and double loop circulatory system
- Complete separation of oxygenated and deoxygenated blood
- G. Gas exchange
- Lungs- invagination of body surface
- Alveoli- site of gas exchange
- Blind pouch construction- reduces water loss
- Limited gas exchange efficiency- only 25% O2 removed from air
- Diaphram and intercostal muscles (ventilate lungs) - negative pressure
- H. Excretory system
- Mammals use kidneys to excrete nitrogenous wastes as urea
- I. Digestive Adaptations
- (1) Dentition
- Carnivores- canines and incisors
- Herbivores- molars with large surface area and small incisors
- Omnivores- unspecialized
- (2) Length of digestive system- correlates with diet
- Herbivores have longer alimentary canal relative to body size than carnivores
- (3) Specialized fermentation chambers
- Symbiotic bacteria and protozoa (convent cellulose to sugar)
- Cecum- horses, rabbits, koala
- Rumen- cows, sheep , deer
- (4) Tongues- protrusible
- Anteaters and Mexican long-tongued bat
- A. Evolved approx. 200 mya
- B. Archaeopteryx- "ancient wing"
- Discovered in Bavaria, Germany in 1861
- Dated at 150 mya
- Small, bipedal, carnivorous
- Bird-like characteristics
- Wishbone, feathers, wings
- Reptilian Characteristics
- Clawed forelimbs, teeth, long tail
- Other fossil "bird-reptiles" have been discovered in Texas, Spain and China
- Sinosauropteryx- early feathered, flightless dinosaur
- A. Origin- primitive amphibians about 280 mya
- B. Three lineages
- (1) Turtles- no skull openings behind eye orbit
- (2) All other reptiles + birds- 2 openings behind orbit
- (3) Mammals- one opening behind orbit
- Subclass Sarcopterygii
- Fleshy muscular fins
- Lungfishes- 3 genera in Australia, S America etc still use lung for gas exchange
- Lobe-finned fishes- stubby fins, supported by skeletal extensions now lungless
- Ancestors of amphibians
- Ex) Coelcanth
- (b) Subclass Actinopterygii
- Ray finned fish
- Most modern bony fish
- Lung developed into swim bladder (to change fish buoyancy)
Class Reptilia Characteristics
Class Mammalia
- Diversity represented by 3 groups
- A. Monotremes- "one hole"
- Egg laying mammals
- (1) Duck-billed platypus and echidna
- (2) Endothermic
- (3) Eggs deposited in the ground-incubated by female
- (4) Milk seeps from modified sweat glands (no nipples)
- B. Marsupials- "pouch"
- Pouched mammals
- (1) kangaroos, koalas, opposums
- (2) Develops in female, gestation period is short
- (3) Continues development in pouch
- (4) Lower metabolic rate than placental mammals
- C. Placental Mammals
- (1) Placenta- organ of exchange between maternal and fetal blood
- (2) Born in more advanced stage of development
- (3) Diversified rapidly (70-45 mya)
- (4) Varied dentition
- A. Paired limbs-
- 2 pairs of limbs with 5 toes
- B. Thick, scaly skin with keratin
- To prevent water loss
- 6000 species
- C. Amniotic egg
- With leathery shell and extraembryonic membranes
- Chorion- gas exchange
- Allantois- excretion
- Amnion- surrounds amniotic fluid
- Yolk sac- nourish embryo
- D. Internal fertilization
- Oviparous, some ovoviviparous, viviparous
- E. Ectothermic- "cold blooded"
- Do not use metabolism to control body temp
- Behavioral adaptations used to regulate temperature
- Survive on 10% of calories required by equal size mammal
- F. Gas exchange
- More efficient lungs than amphibians
- Expandable rib cage with negative pressure breathing
- G. Circulation
- Double loop circulatory pathway
- Ventricle septum- prevents mixing of oxygenated and deoxigenated blood
- 3 or 4 chambered heart (crocs)
- H. Excretion and Osmoregulation
- (1) efficient kidneys excrete uric acid- dry excretory product
- (2) osmoregualtion
- Marine turtles exrete excress salt through modified tear glands
- Marine iguanas excrete salt through nasal salt gland
- Sea snakes- excrete excess salt though salivary gland
- I. Digestion adaptations
- (1) Snakes have fangs and posteriorly pointed teeth
- (2) gizzard
- Crocs have a muscular gizzard with gastroliths for grinding food, bones shells and horns
- (3) Regulate body temp for optimal digestion
- Crocodillians preferred body temp is 88 degrees F
- (4) Venom glands
- Used by snakes to capture prey
- Not really for defense since it is metabolically expensive
- 30 orders
- Beak and feet type
- Habitat and behavior
- A. Order Chelonia- turtles and tortoises
- 225 species
- Marine, freshwater and terrestrial environments
- Shell fused with ribs and thoracic vertebrae
- Lack teeth but have sharp beak
- B. Order Squamata
- Scale to bear
- Lizards and snakes
- (1) 5600 species, most abundant and diverse order
- (2) didn't get this....
- C. Order Crocodillia
- (1) Crocs and alligators, 21 species
- (2) Living reptiles most closely related to dinos and birds
- (3) Exhibit parental care and nest building