Tedra McNairApril 2, 2009

Period, 2

What Is A Chordate?Chordates (KAWR-dayts) are members of the

phylum Chordata.To be considered a chordate an animal must

have three key characteristics

A Dorsal Hollow Nerve ChordPharyngeal (fuh-RIN-jee-ul) pouchesA Tail That Extends Beyond The Anus

Pharyngeal Pouches (P. Pouches)Shark Pharyngeal

Are structures that are paired in the throat (or pharynx) region. In some chordates like fishes and amphibians they develop slits that connect the P. Pouches to the outside of the body.

What Is A Fish?Anatomy of a Fish

Fishes are aquatic vertebrates

Most fish have paired fins, scales, and gills.

Fins are used for movement.

Scales are used for protection.

Gills are used for exchanging gases.

The First Fishes

Ancient Jawless Fish

The Earliest fish to appear in record were odd looking. They were also jawless with armored body plates. They lived in the oceans in Cambrian Period, about 510 million years ago.

Evolution of Fish

Fishes were the first vertebrates to evolve. The evolution of jaws and paired fins were a key development during the upcoming of fishes.

The First Fishes

Function of Fish

FeedingFishes are seen in every mode of feeding. Such as

herbivores, carnivores, parasites, filter feeders, and detritus feeders. Some carp, eat algae, aquatic plants, worms, mollusks, arthropods, dead fish, and detritus. Fish such as the Barracuda, are highly specialized carnivores.

The fish above are Deep-Sea Anglerfish, it uses a fleshy bait a.k.a. built in “fishing pole” to prey on other fish. A perfect example of a carnivore.

Various Fish That Are Unique1.) Doryaspis, 2.)Flying Fish 4.)Southern Stingray 4.)African Lung Fish