Intro to - Phylum Chordata (Fish, Amphibians, Reptiles, Birds and Mammals)

Chordates, at some stage in their lives, have a:

• Dorsal (hollow nerve cord), • Notochord (supports nerve cord during embryonic

phase), • Pharyngeal pouches (paired slits in throat region –

can become gills)• Tail that extends beyond anus

Intro to - Phylum Chordata Most Chordates are Vertebrate, meaning

they have a back bone Fish, Amphibians, Reptiles, Birds and Mammals

2 exceptionsTunicates Lancelets

Phylum Chordata - Fish

Aquatic vertebrates; most have paired fins, scales, and gills

Environment Salt and Fresh water Most fish cannot live in both types of

water because their kidneys cannot maintain homeostasis

Food Source Herbivores, carnivores, parasites, filter

feeders, and detritus feeds (a single fish may exhibit several modes of feeding, depending on what type of food is available)

Maintaining Homeostasis - Internal(Circulation, Respiration, Excretion)

Have gills

Closed circulatory system with a heart that pumps blood around the body in a single loop from heart to gills then gills to rest of body

Rid their body of nitrogenous waste through ammonia through the gills or kidney

Maintaining Homeostasis - External(Response)

Well developed nervous system with a brain, cerebrum, cerebellum, and a medulla oblongata.

Lateral line system- senses other fish or prey near by

Movement They alternate contracting paired sets of

muscles on either side of the backbone, creating a S-shaped curve down their bodies

Reproduction External or Internal fertilization In many fish the female lays the eggs

and the embryos develop and hatch outside of her body.Evolutionary Milestone Vertebrate - notochord

Picture and Vocabulary Picture on page 771 Figure 30-6

Vocabulary: cartilage(773), swim bladder(777)