Presentation on theme: "10. PHYLUM CHORDATA Dorsal Notochord-long rod that supports the body-becomes the vertebrae in most. Dorsal Nerve cord-becomes the central nervous system."— Presentation transcript:
1 10. PHYLUM CHORDATADorsal Notochord-long rod that supports the body-becomes the vertebrae in most.Dorsal Nerve cord-becomes the central nervous system.Pharyngeal gill slits-openings in the throat for feeding & breathing-becomes the Pharynx in humans.Tail-forms in embryos and extends past the anus.
5 SUBCLASS AGNATHA Jawless fish, that are the only vertebrate parasites. Hagfish live in salt,Lampreys live in freshWater.Have a sucker-like oral disk, with teeth that rasp the flesh & suck out juices from tissue.
7 CARTILAGINOUS FISH 850 Species of Sharks, Rays & Skate Skeleton is made of cartilage. S-shaped swimming/rigid fins.Gill slits.Store oils & constant motion to stay afloat.Scales are small bony plates (at one time used as sandpaper).
8 RAYS & SKATES Flattened body for a bottom-dwelling niche Spiracles & eyes on the dorsal side.Mouth, nostrils & gill slits on ventral side.Stingrays have a hollow barb.Manta ray grows to 18’.
9 SHARKS Close to 300 species. Largest fish in the world-Whale Shark. Can smell1drop/bloodIn 1 million parts/water.Lateral line detect vibrations in the waterAmpullae of LorenziniSense changes in electrical field.
12 CLASS OSTEICHTHYES (BONY FISH) 96% of all fish belong to this group.Bony skeletons, gill operculum's.Rigid bodies, flexible fins.Swim bladders for buoyancy.Chromatophores for color.
13 SKIN & SCALESThe skin of bony fish has chromatophores-mating, camouflage.Light, flexible scales for protection.Produce mucus to reduce friction in water & protect against predators.
14 FINS & LOCOMOTIONDue to the rigid nature of their body, bony fish “flex” their fins for propulsion.Paired fins are for fine movements.Dorsal & Ventral are used to stabilize.Caudal is for speed!
15 SWIM BLADDER & GILLSSwim/air bladder-gas filled sac that can be used for buoyancy, sound & protection.Gills extract Oxygen efficiently from water.Covered by an operculum, there are 3 parts-gill raker, gill arch & gill filaments.Blood flow in the filaments is opposite the flow of water resulting in the greatest amount of gas exchange!
21 LATERAL LINELateral line is a series of pits on the side of a fish that lead directly to spinal cord.It can sense the slightest movements in the water. (vibrations)Schooling: fish use this sense to school..(about 80 % of all species school at one time)Schooling helps with: mating,Protection in #’s, disruptive.
22 REPRODUCTIONOviparous-both sexes spawn & eggs are fertilized externally.Ovoviparous-some incubate the eggsViviparous-some species actually bear their young live!
23 Migrations Catadromous- Breed in the oceans but live in freshwater Eels migrate to the Sargasso Sea, they spawn at depths of 300 meters and die when done
24 Anadromous- Breed in freshwater but live in salt Atlantic Salmon makes multiple trips in its lifetimePacific Salmon only once