Presence of pharyngeal slits

which are openings between the

throat and the outside. It performs

various function such as to filter

food particles and gaseous

exchange.

Presence of post-anal tail, an

extension of the notochord that

extends beyond the anus.

Invertebrate Chordates

Vertebrate Chordates

- These are the chordates

whose notochord remain during

the entire life of the organisms.

There are two distinct groups:

cephalochordate and tunicata

-it is represented by the lancelet

or amphioxus, a chordate with a

fishlike appearance. It lacks

bones and brains, but with a

notochord and a nerve cord just

above it.

- an unusual chordate that lives

attached to the seabed. The

swimming larva of the organism

contains the notochord, and all

the rest of the distinguishing

features of chordates.

- are the chordates that have

notochord and pharyngeal slits

during the early stages of

development. As the animals

mature, rings of bones called

vertebrae replace the notochord.

The vertebrate chordates are

divided into seven classes.

Class Agnatha (a- = not, without;

gnathos = jaw). This is represented

by the lamprey, an eel-shaped

jawless fish that is considered as

the vampire of the ocean

because it preys on other fish by

sucking their blood.

-( chondro = cartilage; ichthyes =

fish). The fish with cartilaginous

endoskeleton. Sharks and sting

rays represent this class.

-(osteon = bone; ichthyes = fish )

The class of the bony fishes. This

group consist of many members.

Milkfish

- (amphios = on both sides,

double; bios = life). Named

because in their life cycle, the

larval part of the life of the

amphibians is spent in water and

the adult part is spent on land.

They are the first land vertebrates

to emerge.

Frog Toad

Salamander

- (repere = to creep). Reptiles

have bodies covered with dry,

cornified scales. Their eggs are

covered with leathery shells.

Crocodile Turtle

Snakes Lizard

- (aves = birds). Aves have bodies

covered with feathers, scaly feet

that are adapted to the kind of

environment they live, wings that

are adapted for flight, and the

beaks that are adapted to the kind

of food they eat.

- (mamma = breasts). The presence

of breasts is a distinguishing feature of

mammals. Another distinguishing

feature of mammals is that their bodies

are covered with hair. Almost all

mammals are vivaparous.

Mammals are divided into three

subclasses: monotremata, marsupialia

and placetals

- (trema = hole). Monotremes

have bodies covered with thick

furs. They have breast that lack

nipples, but secrete milk. These

mammals are unique as they are

the only egg-laying (ovaparous)

mammals. Their young lick the

milk that oozes in their thick fur.

Spiny Anteater Duck-billed platypus

- (marsupium = bag or pouch).

Described as pouched mammals.

The marsupium contains the

nipples that secrete milk.

Kangaroo, koala and opossums

represents this group.

Kangaroo Koala Opossum

- Placenta pertains to a part in

the womb where the young is

nourished as it undergoes

development until birth. This

group comprises the largest and

the most diverse forms of

chordates. Placental mammals

are divided into different orders.