Phylum Chordata: Fishes

Phylum Chordata

CharacteristicsHollow nerve chordNotochord Gill slits/Pharyngeal pouchesDigestive tubePost anal tail

Group of VertebratesFishesAmphibiansReptilesBirdsMammal

FishesWater dwelling vertebrates that may have scales, fins and throats with gill slits.Close circulatory system.Contains tube like kidneys.Most species have separate males and females.External fertilization.

Classes of FishClass Agnathostomata (Lampreys and Hagfishes)Class Chondrichthyes (Shark, Rays, and Skates)Class Osteichthyes (Tuna, Carp, Salmons, Stugeons)

Class Agnathostomata

CharacteristicsoAbsence of jawsoLack paired fins (Pelvic and pectoral)oSkeleton made of cartilageoRound eel-like body with a compressed caudal fin

Characteristics oSoft skin devoid of scalesoLack swim bladders and gill covers (Operculum)oTwo chambered heartoLateral linesoNo external ears and eyelids instead OtolithsoExternal FertilizationoOviparous

Class Chondrichthyes

Carcharadon carcharias

•Great white sharks swim constantly with their mouth slightly open to allow water to pass in and out through their gills.

•Source: http://channel.nationalgeographic.com/

  The manta ray is the largest ray and one of the five largest species of fish in the world. Manta is a Spanish word meaning “blanket.”

CharacteristicsoSkeleton made of cartilageoBody covered with triangular placoid scalesoVentral subterminal mouth with several rows of triangular teeth.

CharacteristicsoInternal fertilizationoOvoviviparousoTwo chambered heartoNo external ears and eyelids

Class Osteichthyes

Yellow Fin Tuna

White Sturgeon

Carp

Salmon

CharacteristicsoSkeleton made of bonesoLateral linesoTwo chambered heartoOperculum covering the gillsoSwim bladder

CharacteristicsoPaired fins made of rays and spines or lobed fins lacking the rays and spines.oVarious types of scales (ctenoid, ganoid, cycloid)oExternal fertilizationoSpawning and oviparousoNo external ears and eyelids