COMPARING VERTEBRATES

What is a vertebrate? Vertebrates are animals with an internal skeleton made of bone Although vertebrates represent only a very small percentage of all animals, their size and mobility often allow them to dominate their environment.

What kinds of animals are included in “vertebrates”? Fish Amphibians Reptiles Birds Mammals

FISH

There are three types of fish: Jawless fish –Ex: Hagfish Cartilaginous fish –Ex: Sharks Bony fish –Ex: Goldfish

Fish Movement All fish have an endoskeleton made up of either cartilage or bone Muscles attached to the endoskeleton allow fish to make strong movements Fins on fish increase stability and help them move forward Some fish use swim bladders to help keep them afloat

How do fish respond to the environment? Fish have many organs to allow them to sense the environment –Eyes, nostrils, taste buds, inner ears Fish have a unique organ called the lateral line which senses vibrations and helps fish direct their movement

Respiration: How do fish get oxygen? Fish use their gills to get the oxygen they need from the water Gills are made up of fingerlike projections through which gases enter and exit the blood In some fish, gills are covered by an operculum

Circulation: How does blood circulate through a fish’s body? Fish have a single-loop circulatory system Blood travels from the gills to the body to the heart and back to the gills Fish hearts have only two chambers (one atrium and one ventricle)

How do fish maintain water balance? Fish have kidneys –to regulate their body’s salt and water balance –to remove wastes from the blood Excess water and body wastes leave the kidneys as urine

How do fish reproduce? Most fish reproduce sexually through external fertilization in a process called spawning During spawning –a female fish releases eggs into the water –then, a male fish swims over them and releases sperm

AMPHIBIANS

Amphibian Members Frogs Salamanders Newts

Amphibians have adaptations that allow them to live on land Legs Lungs Double-loop Blood Circulation Cutaneous (skin) Respiration

Amphibian Movement Amphibians move very differently than fish because of where they move (water vs. land) Land living animals rely on their stronger skeletons for support against gravity Limbs (arms and legs) allow for movement Frogs have thick hip bones to absorb impact of landing after jumping

How do amphibians respond to the environment? Primary sensory organs of amphibians are the eyes and ears Vision is important in hunting and avoiding predators Sounds are transmitted to inner ear by the eardrum Amphibians have a well developed brain

Respiration: How do amphibians get oxygen? Most adult amphibians get oxygen using lungs Lungs are less effective than gills, but they don’t need to be as effective as gills because air has MUCH more oxygen than water does Many amphibians also get oxygen through their thin, moist skin

Circulation: How does blood circulate through an amphibian’s body? Amphibians have a double- loop circulatory system Structure of amphibian heart and circulatory system allows oxygen to be delivered to body more efficiently than fish Amphibian hearts have 3 chambers (2 atria & 1 ventricle)

How do amphibians maintain water balance? Amphibians have kidneys like fish Mucous glands on skin keep them moist and prevent them from drying out

How do amphibians reproduce? Amphibians are still tied to the water because it is where they reproduce They reproduce sexually by external fertilization Females lay eggs first, then they are fertilized by male Young amphibians develop in water as tadpoles and breathe through their skin

REPTILES

Reptile Characteristics First to live completely on land Dominated during age of Dinosaurs Can be found in a range of habitats (except extreme cold) All modern reptiles –Have scales –Have clawed toes (except snakes) –Are ectothermic –Lack feathers or hair

Reptile Movement Have strong endoskeleton made of bone Legs of reptile (if any) are positioned more directly under body than limbs of amphibians This allows reptiles to move more easily on land Claws are used for climbing and digging

How do reptiles respond to the environment? Many species of reptiles have keen vision to detect predators and prey Reptiles use their Jacobson’s organ to “taste” the environment Reptiles are ectothermic (can’t heat bodies using their metabolism) –Body temperature is mostly determined by environmental temperature Many reptiles can change their body temperature by “sunning” or “shading” themselves

Respiration: How do reptiles get oxygen? Lungs have a large surface area, so they can get more oxygen in one breath than amphibians can Strong muscles in rib cage move air into and out of lungs quickly, maximizing lung efficiency

Circulation: How does blood circulate through a reptile’s body? Reptiles still have a 3 chamber heart, but the lower chamber (ventricle) is partially divided, reducing the mixing of oxygen-poor and oxygen-rich blood Therefore, oxygen is delivered to the body cells in reptiles more efficiently than it is in amphibians

Reptile Reproduction Reptilian eggs are fertilized internally (protects gamete from drying out on land) Many reptiles are oviparous –Young hatch from egg laid outside of mother’s body –Eggs of these reptiles are not protected Some reptiles are ovoviviparous –Fertilized eggs remain inside female’s body –Eggs of these reptiles are protected

Reptile Reproduction The amniotic egg is crucial to the reptile’s success as a terrestrial animal It contains a water and food supply and is watertight which prevents drying out –Albumen (egg white) protects and cushions developing embryo –Yolk sac contains embryo’s main food supply

BIRDS

Bird Characteristics A characteristic that birds have in common with reptiles is the amniotic egg Characteristics that are unique to birds are wings, feathers, beaks, and hollow bones Birds are endothermic: they generate enough heat through metabolism to maintain a high body temperature, regardless of the temperature of the environment

Bird Characteristics Birds need A LOT of energy to fly and regulate body temperature This energy is obtained by a quick and efficient digestive system (they eat a lot!)

Bird Adaptations Birds have adaptations to allow them to fly, to eat the food that they eat, and to live in the environments that they live in Feathers insulate birds from water and cold temperatures. –They may also be plucked to line the nest and provide insulation to the eggs and young. –The individual feathers in the wings and tail play important roles in controlling flight.

Bird Adaptations The bones of birds are thin and hollow Many bones are fused, making the skeleton more rigid Different beaks and feet are adaptations for different bird lifestyles –Perching birds have curved toes/water birds have webbed toes –Carnivorous birds have sharp beaks/water birds have rounded beaks to eat water plants

Respiration: How do birds get oxygen? Birds need a huge amount of energy to fly, which means they need a huge amount of oxygen They have air-sacs which are oxygen reservoirs to keep a constant flow of fresh air through the lungs

Circulation: How does blood circulate through a bird’s body? For birds to circulate the huge amounts of oxygen needed for flight to all of their body cells, they need a very efficient heart and circulatory system Birds have four heart chambers and a double-loop circulatory system Their hearts also beat very fast when extra oxygen is needed

Bird Reproduction Internal fertilization Amniotic egg w/ hard shell (prevents drying out) Birds usually care for their eggs and for their young Nests are built to protect eggs Monogamy common

MAMMALS

Key Characteristics of Mammals Mammals have hair –Uses include insulation, camouflage, advertising, sensing environment. Mammals are endothermic –(Can maintain a constant body temp. despite temp. changes in environment) –This allows animals to live in cold temps. & be very active

Key Characteristics of Mammals Mammals have specialized teeth that reflect the differences in their diets –Mammalian teeth are not continuously replaced (they only have two sets!) –Four types of teeth: incisors, canines, premolars, molars

How do Mammals reproduce? Internal fertilization occurs Parental care in mammals is quite different from other vertebrates –Young mammals depend on their mothers for a relatively long time –They receive food, protection and shelter from her

How do mammals move and respond to the environment? Mammals use various methods of locomotion –Modes include running, hopping, climbing, burrowing, flying, and swimming Bodies are adapted to moving around in particular environments

How do mammals move and respond to the environment? Mammals rely on their senses for survival The importance of a sense depends on a mammal’s lifestyle and habitat Echolocation is used by bats and dolphins to “see” their prey or obstacles in the environment

Respiration: How do Mammals get Oxygen? Lungs of mammals have LARGE internal surface area (more gas exchange per breath) Aided by a diaphragm which enlarges abdominal cavity drawing air in

Circulation: How do Mammals get oxygen to circulate around their bodies? Mammals have a 4-chambered heart This ensures only oxygen rich blood gets to the tissues

Groups of Mammals Monotremes are mammals that lay eggs –They are only found in Australia and New Guinea –Female monotremes do not have nipples: the young lap up milk that oozes from glands located in mother’s belly

Groups of Mammals Marsupials spend most of their time developing in their mother’s pouch –Mostly found in Australia & South America

Groups of Mammals Placental Mammals are the most familiar types of mammals –Make up 95% of all mammalian species –The young develop inside female’s uterus, where they are nourished by her blood –Many are domesticated