Phylum Chordata Includes the well known vertebrates: (fish, amphibians, reptiles, birds and mammals)

What Is A Chordate? 4 characteristics present at some stage of life A dorsal, hollow nerve cord (called spinal cord in vertebrates) Notochord – a supporting rod (develops into a backbone in vertebrates) Pharyngeal pouches Tail that extends beyond the anus The hollow nerve cord runs along the back part of the body and has nerves branching from it at regular intervals, connected to internal organs, muscles, & sense organs. The notochord is a long supporting rod running through the body just below the nerve cord. Most chordates have a notochord only when they are embryos. Pharyngeal pouches are paired structures in the throat region that develop into gills in some chordates. At some point in their lives, all chordates have a tail extending beyond the anus, which may contain bone and muscle.

General Chordate Structure Notochord Hollow Nerve Cord Muscle Segments Tail Anus Mouth Pharyngeal Pouches

Nonvertebrate Chordates Tunicates - look nothing like other chordates The larval form has all the chordate characteristics The adult tunicates have neither a notochord nor a tail Lancelets are more fishlike and have a definite head containing a mouth

Fish Classes: Agnatha – jawless fish Chondrichthyes – cartilaginous fish Osteichthyes – bony fish

Characteristics Integumentary Skeletal/ Muscular Circulation Scales & paired fins Skeletal/ Muscular Endoskeleton - made of cartilage or bone Circulation 2-chambered heart; closed-single loop circulation

Characteristics Reproductive Nervous Respiratory Internal or external; Oviparous, Ovoviviparous, Viviparous Eggs house outside the mothers body Born alive after developing eggs inside of mother’s body Bear live young that are nourished by mother Nervous Brain, lateral lines Respiratory Gills

Characteristics Digestive Excretory Variety in types of feeding; complete digestive system Excretory Remove ammonia from gills & kidneys

Characteristics Body Temperature Habitat Ectothermic: Cold blooded; regulates it’s body temperature by exchanging heat with it’s surroundings Habitat Marine & Fresh Water

Groups of fish Fish are the first vertebrates to evolve Jawless Fish – have not true teeth or jaws; ex: lampreys & hagfish, parasitic

Cartilage Fish – skeleton made of cartilage; ex: sharks, rays, skates

Bony Fish – skeleton made of hard, calcified tissue  bone; ex: perch, goldfish

Bony Fish Structures Dorsal Fins Eye Lateral line Mouth Caudal fin Operculum Anal fin Pectoral fin Pelvic fin

Swim Bladder Spinal Cord Reproductive organ Brain Gills Heart Liver Intestine Gallbladder Stomach Anus

Ticket Out On a piece of paper, answer the following: What is the purpose of the swim bladder? What is the difference between bony fish and cartilaginous fish? What is the difference between: Oviparous, Ovoviviparous, Viviparous