Lab 18: Chordates II

-Also known as the cartilaginous fishes

-Mostly marine fishes

-They contain one pair of powerful jaws

-Contain cartilaginous endoskeleton

-The embryonic notochord is present throughout life

-Skin is covered by minute tooth-like structures called placoid scales

-Contain 5-7 pairs of gills

-Lack air bladders so they swim actively to avoid sinking

-Sharks and Rays are the best examples of these

What class do these characteristics describe?

-Possess a well-developed head (cranium)

-Most chordates have a skill enclosing their brain, eyes, inner ear, etc.

+All but one group of chordates (the hagfishes) also convert their notochord into a vertebral column (backbone) thus qualifying as one)

-Epidermis is multi-layered

-Have a well developed coelom

-Have well-developed respiratory & excretory systems

-They are unisexual & reproduce sexually

+Hagfishes are the exception

-Vertebrata is further classified into 7 classes

What subphylum are these characteristics describing?

-Also known as the jawless fishes -- lack jaws

-Paired fins are generally absent

-Early species had heavy bony scales & plates in their skin

+These are not present in currently living species

-In most cases the skeleton is cartilaginous

-The embryonic notochord persists in the adult

-7 or more paired gill pouches are present

Digestive system lacks a stomach

-Lampreys & Hagfishes are the best examples of this class

What class are these characteristics describing?

-Also known as the bony fishes

-Vertebrae numerous

-Skin with mucous glands & embedded dermal scales

+Some without scales

-Paired fins

-Mouth with many teeth (some toothless)

-Jaws present

-One pair of respiration by gills supported by bony gill arches and covered by an operculum

-Lobe-finned and ray-finned fishes are the best examples of this class

What class are these characteristics describing?

-Can live both on land and in water(amphi-)

-Ecthothermic (cold-blooded) animals

-Body is divided into head & trunk (tail may be present)

-Skin is smooth & rough without any scales, but with glands that make it moist

-Unpaired fins might be present

-2 pairs of limbs for locomotion

-Respire through the lungs & skin. Gills might be present externally in some adults

- Frogs & Salamanders are the best example for this class

What class are these characteristics describing?

-Creeping & burrowing terrestrial animals

-Have backbones

Bodies are completely covered with scales or scutes

-Ectothermic (cold-blooded)

-Produce hard/soft shelled eggs (oviparous) or bear live young

-All species of these organisms have at least 1 lung

-Typically have 4 legs

-Live in a wide range of habitats

-Snakes & Turtles are the best examples of this class

What class are these characteristics describing?

-Commonly known as the birds

Homothermous (warm-blooded) animals

-Have backbones, beaks, sharp eyesight

-Forelimbs are modified into wings

+Have well-developed flight muscles that help during the flight

-Hindlimbs are adapted for walking, hopping, perching, grasping, wading, & swimming

-Have epidermal scales on their legs

-Endoskeleton is bony with long hollow bones filled with air cavities

-Spindle-shaped body minimizes resistance of the wind

-Archaeopteryx (extinct), Eagles, and Herons are the best examples of this class

What class are these characteristics describing?

-Homothermous (warm-blooded); most vivaparous

-Have backbones, skulls, & mammary glands

-Oil glands (sebaceous glands) & sweat glands (sudoriferous glands) present in skin

-Teeth are different types (heterodont) and are embedded in the sockets of jaws

-Respiration is by lungs

-Possess a muscular diaphram dividing trunk into thorax & abdomen

-The coelom is divided into 4 cavities

-Humans, Lions, & Whales are the best examples of this class?

What class are these characteristics describing?

What phylum do these organisms belong to?

What class do these organisms belong to?