CH. 26.1 & 26.2: 41 REPTILES 1
PHYLOGENETIC TREE 2
Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: 1) Crocodila = Crocodiles - 23 species 2) Rhynochocephalia (Sphenodontia) = tautaras (2 species) 3) Squamata = snakes and lizards (~7,900 species) 4) Chelonia (testudines)= turtles and tortoises~ 300 species (~200 living) 3
KEY CHARACTERISTICS Strong, bony skeleton Most have 4 limbs and toes w/ claws Ectothermic Dry, scaly, watertight, skin Well-developed lungs Heart s ventricle partly divided Internal fertilization Lay amniotic eggs on land 4
KEY CHARACTERISTICS Legs positioned more directly under body than amphibians move easily on land Claws great for digging and climbing Can run quickly for short distances (~ 17 mph) 5
NERVOUS SYSTEM Similar to amphibian s Small brain compared to body size Capable of complex behaviors Ex: Elaborate courtship 6
ECTOTHERMIC METABOLISM Body temp. determined by environment Bask in sun or seek shade to regulate Dry scales/plates absorb energy and keep heat in Limits geographical distribution Low temperatures = Sluggish Forces inactivity through winter 7
ECTOTHERMIC METABOLISM 8
ECTOTHERMIC METABOLISM Create this data table in your notes. 9
ECTOTHERMIC METABOLISM 10
ECTOTHERMIC METABOLISM 11
Degrees C ECTOTHERMIC METABOLISM Make one or more line graphs of the temperature data. Explain what the graphs show you. 12
ECTOTHERMIC METABOLISM 13
WATER RETENTION- SKIN Adaptations to free them from water Skin made of light, flexible scales Scales overlap Protective Watertight Reptile Intro 3:30 14
SCALES Scales made of keratin (like your fingernails) Begin as fold of dermis Upper layer of dermis begins to harden and dermis withdraws Leaves a series of overlapping tough scales 15
SCALES All reptiles grow continuously Grow more slowly as they age Scales get larger Shed: Whole skin Large patches Individual scales we ll talk more about scales within each order later 16
SCALES In turtles and crocodiles Begin as local thickening in epidermis Bony plates develop in dermis under scales Do not always form the same pattern as scales above Most do not overlap 17
WATER RETENTION - EGGS Fertilized egg needs moist environment Some snakes bear live young Adaptation: AMNIOTIC EGG Contains: Water Food Watertight shell Most reptiles, all birds, and 3 species of mammals have amniotic eggs 18
THE AMNIOTIC EGG Hard, porous shells allow oxygen to enter and carbon dioxide to leave Albumen (egg white) Protects and cushions embryo Source of protein and water 4 specialized membranes: 1) Amnion 2) Yolk Sac 3) Allantois 4) Chorion 19
THE AMNIOTIC EGG 1) Amnion Encloses embryo in watery environment 2) Yolk Sac Contains yolk food supply Absorbs via blood vessels connected to gut 3) Allantois Sac that stores waste products Gas exchange organ 4) Chorion Allows oxygen to enter and carbon dioxide to leave the egg 20
RESPIRATION No cutaneous respiration LUNGS! Many internal folds Increase surface area Strong muscles attached to rib cage Help move air in and out of lungs Increase efficiency 21
RESPIRATION HEART Divided by septum which extends into ventricle Incomplete separation More efficient than amphibians Crocodiles are unique! Completely divided ventricle with 2 pumping chambers Fully separates lung and body circulation Very efficient! 22
REPRODUCTION Internal fertilization Many are oviparous Young hatch from eggs Most snakes & lizards All turtles and tortoises All birds and 3 species of mammals 23
REPRODUCTION Few reptiles are ovoviviparous (viviparous) ovo = egg, ovum Vive = live Parous = bearing Eggs hatch within body Bear live young No placental attachment Ex: Garter snakes and rattlesnakes Anaconda Birth 2:30 Anaconda Breeding ball 2:00 24
LIZARDS Thorny devil 1:45 Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Common Lizards: iguanas, chameleons, geckos, anoles, and horned lizards 25
LIZARDS Most are carnivores Few = herbivores Lower jaw loosely connected for large prey Most <1 ft in length Monitors = huge! Ex: Komodo dragon Indonesia Largest lizard 10 ft long, 275 lbs Komodo Dragon 2:00 26
LIZARDS Reproduction Eastern Collared Lizard Most lay eggs Deposited in nest Skinks protect Most lizards = no care Whiptails only have females Mates w/ male from another species Females born 2N and fertile! Unusual! Some bear live young 27
DEFENSE TACTICS Some: break off tails Swell up, hiss, or attempt to scare enemy Change color Frilled Lizard Running 1:00 Basilisk lizard 1:25 Blood Squirting Lizard 1:50 28
CHAMELEONS Most, especially males, have Horns Rostral (beak-like) processes Casques (helmet-like structure) and other appendages Some have occipital lobes (earlike) Help them appear larger 29
CHAMELEONS 30
CHAMELEONS Change color fast! According to feelings Plain unless excited If too hot may look bleached = suffering from heat stress 31
CHAMELEONS 4 layers of skin: 1) Epidermis Transparent Shed Made of same material as our fingernails 2) Chromatophore layer yellow and red pigment 3) Melanophore layer reflect blue, brown and black 4) Nether layer white 32
CHAMELEON EYES Eyes shaped like turrets 180 degree vision each eye Can see behind and in front concurrently Brain receives two separate images and makes them one 33
CHAMELEON FEET Zygodactylous (Y-shaped) feet One side 3 toes other has two Many = powerful grip and sharp nails Madagascar Camelion trying to get a date 1:34 34
DANGERS TO LIZARDS Humans: Gather eggs Hunt for food Harvested for skin Habitat loss Predators: Birds Snakes Other lizards Skunks and badgers dig eggs House cats 35
SNAKES Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Common Snakes: Fox Snake, Bullsnake, Garter Snake, Timber Rattlesnake, Hognose Snake 36
SNAKES Carnivores Lower jaw loosely connected Longest: Reticulated Python S. America Upto 33 ft long Largest: Green Anaconda 2x weight of similar length python 37
SNAKES Body Structure Elongated body & organs No pectoral girdle Snake jaw = five points of movement Chin has elastic ligament Comparable to human eating a whole watermelon!! 38
SNAKES 39
SNAKES Feeding Most seize prey & swallow whole Some: Constrict and suffocate prey Kill with venom Opening to respiratory system is on roof of mouth (in front) so it can breathe while eating Snake v. Lizard 1:50 40
SNAKES 41
SNAKES african egg eating snake 2:00 Python eats Alligator5 min 42
SNAKES Tasting the Air Two openings on roof of mouth lead to Jacobson's organ Snake touches tongue to organ, rubbing off scents collected Sends message to brain Meal? Mate? Enemy? Why is tongue forked? Can smell "in stereo Each point on tongue fits into opening to Jacobson's organ If odor stronger on one side, can tell direction 43
SNAKES 44
SNAKES Hearing Acute Lack external ears Inner ears hear low frequency airborne vibrations Hear w/ jaw Ground vibrations transmitted through body to quadrate bone (connection b/w lower jaw and skull) then to middle ear bone (columella) and on to inner ear. Will always hear you coming before you see it! 45
SNAKES Scales/Skin & Molting Most shed 3x or more each year Usually after emerging in spring Depend on growth rate and health Young snake will shed more often than old Skin infection or injury may increase shedding 46
COMMON MISCONCEPTIONS 47
VENOMOUS SNAKES Use fangs to inject venom Venom either: Hemotoxin: affects tissues Neurotoxin: affects nervous system Black Mamba 2:41 48
VENOMOUS SNAKE CHARACTERISTICS Elliptical eye pupils Triangular head Some unique marks Ex: Coral Snake Pit Vipers pit under each eye used as a heat sensor 49
VENOMOUS SNAKES IN WI Massasauga Rattlesnake (endangered) Timber Rattlesnake (protected) 50
MASSASAUGA RATTLESNAKE Sistrurus catenatus 2-3 ft in length Bounty of $5 per tail until 1975 Found rocky, swampy lands of Wisconsin River Prefers to hide Can be aggressive Pit Viper Endangered 51
TIMBER RATTLESNAKE Crotalus horridus Found rocky, forested bluff country in WI Prefers to hide Can be aggressive Pit Viper Endangered 52
TIMBER RATTLESNAKE No, that s not Me!!! It s my friend, who created part of this PowerPoint, handling a Rattler!! 53
HOW DOES THE RATTLE FORM? Loosely joined, thick rings of dry scales Rattle against one another You can NOT tell the age of a rattlesnake by counting the rings in its rattle! New ring is added to base of rattle each time it sheds May get 2-4 new rings a year Old rings wear down and fall off at the tip as snake ages 54
COPPERHEAD Agkistrondon contortrix Pit Viper Hilly parts from Massachuttes to Florida and from Florida to Texas Not real aggressive Venom not as potent as a rattlesnake s Hemotoxin 55
CORAL SNAKE Micrurus fulvius Distinct color pattern red touches yellow Two species found in U.S. One in the SE states and the other native to S. New Mexico and Arizona Short fangs Do not strike but will bite repeatedly when touched Neurotoxin If a coral snake bites you... 5:40 56
COTTONMOUTH WATER MOCCASIN Agkistrodon piscivorus Cousin to Copperhead Aquatic Cotton-like appearance in mouth (bottom picture) Feeds on fish and amphibians Swampy regions of SE U.S. and parts of Illinois, Kansas, Oklahoma, and Texas Highly aggressive 57
DIAMONDBACK RATTLESNAKE Pit Viper All over US except Alaska and Hawaii Prefer hot environments Diamond shapes on back Two species: Eastern and Western Can be albino (no pigment) 58
ASIAN COBRA Naja naja Most feared venomous snake Countless deaths in Asia Forms hood when aroused Can bite or spit venom As long as 6 ft 59
DEFENSE TACTICS Kingsnake (top) Camouflage Mimicry: Ex: kingsnakes coloration looks like coral snakes Create large hood Open mouth, shows flash of white or color, startles predator, and gives escape Hissing Playing dead Shaking tail or rattle Coral Vs. King Snake 1:00 60
SOME NON-VENOMOUS SNAKES IN Round pupils Head inline w/ body not triangular Bite in fear Will not inject venom WISCONSIN 61
GARTER SNAKE Thamnophis sirtalis One of most common snakes in U.S. Up to 3 ft long 6-25 young Eat: Earthworms Frogs Salamanders Fish 62
YELLOW-BELLIED RACER Coluber constrictor Fast! Protected in WI Most ~4 ft long Diurnal (feed in day) Eat small mammals, frogs, lizards, and insects Constrictors 63
BLACK RAT SNAKE Elaphe obsoleta All over U.S. (protected in WI) Constrictors Upto 5 ft long Love rodents, frogs, lizards, and small birds 64
NORTHERN RIBBON SNAKE Thamnophis sauritus Endangered Relative of garter Same habitat and food as garter 65
NORTHERN RINGNECK SNAKE Diadophis punctatus grass snake 1-4 ft long Wide yellow ring around neck Same eating habits as garters 66
EASTERN HOGNOSE SNAKE Heterodon platirhinos play dead when frightened Use upturned snout for digging Feed on frogs and toads If they strike (rarely), they will hit you with their snout and not bite Snake playing dead 1:00 67
NORTHERN WATER SNAKE Nerodia sipedon Primarily aquatic Aggressive if provoked ~ 3 ft long Commonly mistaken as a copperhead Feed on fish, frogs, and toads Up to 60 young in den 68
DANGERS TO SNAKES Humans Captured and shipped for pets Make anti-venom from venomous ones Shoes, purses and belts from skin Killed out of fear Habitat loss Natural Predators Crows, ravens, weasels, mink, raccoons, foxes, ground squirrels, skunks, hawks, owls and etc. Red-Tailed Hawk vs. Rattler 2:00 69
TURTLES & TORTOISES Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Chelonia (Testudines) (greek for tortoise) ~250 species Common: Snapper, Painted, Sliders, Sea Turtles 70
TURTLES & TORTOISES Most omnivorous Some herbivorous Some have jaws for crushing shells of mollusks Largest: Leatherback Carapace length: 8 feet Weight: 1,800 pounds Intro Clip Smallest: Bog turtle ~ 3 inches 71
TURTLE, TORTOISE, AND TERRAPIN Different in: Where they live How habitat is used Names used differently in other countries Ex: Australia Only sea turtles are called turtles; Everything else is called a tortoise. 72
TURTLES Live most of life in water Usually have webbed feet Cold weather: burrow into mud Go into torpor until spring Sea turtles: Long flippers for feet streamlined body rarely leave ocean except to lay eggs Fresh water turtles Swim a lot, but also bask a lot 73
TORTOISES Land-dwellers Eat low-growing shrubs, grasses, and cacti No webbed feet High domed shell Strong legs to dig burrows Go underground when hot 74
TERRAPIN Indian word = "a little turtle Always lives near water Time on land and water Often found in brackish, swampy areas 75
BODY STRUCTURE Head covered by hard scales (most) 3 parts to shell (59-61 bones total in shell) 1) Carapace Ribs, backbone, and breastbone are fused 2) Plastron 3) Bridge 76
TURTLE, TORTOISE, AND TERRAPIN 77
FEEDING No teeth Beak with sharp edges Strong jaws (most) Side note: Many sea turtles eat jellyfish Turtle-Cam Shows Jellyfish Lunch2 min 78
HEARING Bone in middle ear conducts vibrations to inner ear Side note: Sea turtles respond to low frequency sounds and vibrations 79
SEEING Most see color See well under water but not on land Side note: Under experimental conditions, loggerhead and green sea turtle hatchlings exhibited a preference for nearultraviolet, violet, and bluegreen light 80
SMELLING Most very acute even in water Opens mouth slightly, draws water in through nose Side note: Pulsating movements of throat are thought to be associated with smelling too 81
Males: longer, thicker tail with the vent closer to tip Females: smaller, thinner tail with vent closer to main body Often males have longer fore claws than females 82
DANGERS TO TURTLES Humans Pet trade Live animal markets Litter and pollution Turtle crossings Disturbing nest areas Habitat loss Natural Predators Weasels, mink, raccoons, foxes, ground squirrels, skunks, hawks, owls and sharks kill turtles 83
CROCODILIA 84
CROCODILIANS Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Crocodilia Includes: Crocodiles, Alligators, Caimans, and Gavial Crocodile Hunter Largest Croc 10:00 85
CROCODILIANS Aggressive Carnivorous Stealthy Most very large Ex: American Alligator 18 feet Nile Crocodiles 20 feet 1,650 pounds 86
REPRODUCTION Eggs deposited in nest of rotten vegetation Young hatch using an egg tooth Mother tears up nest after hatching Young stay with mother up to a year Care for young! Gator Water Dance - 2 min Croc Carries Babies in Jaws 2:14 87
CROCODILIAN ADAPTATIONS 88
SPECIAL ADAPTATIONS Eyes Nictating membrane Good vision above water Color?!? Ears Great hearing Well developed inner ear External ears can be covered No water enters 89
SPECIAL ADAPTATIONS Nostrils Top of snout Great sense of smell Teeth Replaced continuously Seize and hold prey Powerful jaws for crushing 90
SPECIAL ADAPTATIONS Heart Fully divided by septum 4 chambers Throat Vocal! Hiss, snarl, chirp (babies) Feet Front clawed (traction) Rear webbed (swimming) Side note: legs fold back when swimming swiftly 91
SPECIAL ADAPTATIONS Stomach 2 chambers 1: grinds food 2: digests/removes nutrients Side note: Crocodiles have most acidic system of any animal. It can digests bones, hooves, and horns! 92
SPECIAL ADAPTATIONS Palatal Valve Fleshy extension at rear of lower palate/tongue Seals opening to throat Can open mouth underwater Useful during prey capture 93
SIDE NOTE: LOCOMOTION Belly Crawl (slow movement) High Walk HOW CAN THEY MOVE SO FAST? Ankle joint passes in ~ straight line between the upper and lower bones of the ankle Can rotate their foot 90 degrees so it is facing forwards rather than to the side. Can move legs closer to body Can lift entire body off ground Provides support 94
(4) SIDE NOTE: LOCOMOTION Galloping Unique to Crocodilians Reach speeds of 20 mph Swimming Reach speeds of 10 mph Leaping & Lunging More common in juveniles than in adults 95
CROC AND GATOR DIFFERENCES Snout/Jaw Shape Crocodile: narrow, V shaped jaw Alligator: wide, U shaped jaw Teeth Placement Crocodile: jaws same size, teeth interlock Alligator: Lower jaw teeth completely hidden because upper jaw is larger. 96
CROC AND GATOR DIFFERENCES Lingual salt glands Modified salivary glands on tongue Crocs = more tolerant to salt water bc have full use Alligators and caimans can not use for excreting large amounts of salt 97
CROC AND GATOR DIFFERENCES Integumentary sense organs: Small pits around upper and lower jaws Detect pressure changes in water Help locate prey Side note: Crocs have similar organs covering entire body Gators and caimans only have around jaws Scientists not sure what the extras in crocs do help id chemicals? Salinity? Pressure? Believed to extend the sensory surface over the crocodile's entire body, but previous researchers have suggested they may assist in chemical reception, or even salinity detection 98
DANGERS TO CROCODILIANS Humans Poached for: Skins Food Habitat loss Pollution Drowning in fishing nets 99
TUATARAS Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Rhynchocephalia (Sphenodontia) Only 2 species Found in New Zealand 100
TUATARAS From Maori word meaning peaks on back Lizard-like Up to 2 feet long Most active at LOW temperatures Nocturnal Spiky scales down center of back 101
TUATARAS Slow metabolism Lay soft-shelled eggs Eggs incubate for 13 to 16 months Side note: tuataras can go for an hour without breathing! 102
SIDE NOTES: INTERESTING FACTS Like alligators, the temp of egg in nest determines tuatara s gender One degree centigrade can change the gender of all eggs in nest! Higher temps create males Could global warming could have anon the tuatara populations? 103