200 likes | 533 Views
FISH FACTS. PHYLUM CHORDATA. Dorsal 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.
E N D
PHYLUM CHORDATA • Dorsal 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.
CLASSES OF CHORDATES The group we care about most in Marine Biology
CLASS PISCES SUBCLASS SUBCLASS
SUBCLASS AGNATHA • Jawless fish, that are the only vertebrate parasites. • Hagfish live in salt water • Lampreys live in fresh water • Have a sucker-like oral disk, with teeth that rasp the flesh & suck out juices from tissue.
CARTILAGINOUS FISH • 850 Species of Sharks, Rays, & Skates • Skeleton is made of cartilage. • External Gill slits. • Store oils & constant motion to stay afloat. • Scales are small bony plates (at one time used as sandpaper).
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’.
SHARKS • Close to 300 species. • Largest fish in the world-Whale Shark. • Can smell blood • Lateral line detect vibrations in the water • Ampullae of Lorenzini Sense changes in electrical field. We aren’t here to hunt humans, we are misunderstood!!!
Shark Food Facts • Many rows of teeth • Usually tear off pieces of food and swallow it whole • Strange things sharks have had in their digestive system: • Legs of lamb, horseflesh, part of a ham, front half of a bulldog, rear half of a pig, coal, 34 leather jackets, parts of a reindeer, telephone books, pots and pans, bottle of madeira wine, a keg of nails, kerosene lantern
CLASS OSTEICHTHYES(BONY FISH) • 96% of all fish belong to this group. • Bony skeletons, gill operculums. • Rigid bodies, flexible fins. • Swim bladders for buoyancy. • Chromatophores for color.
SKIN & SCALES • The skin of bony fish has chromatophores • Light, flexible scales for protection. • Produce mucus to reduce friction in water & protect against predators.
FINS & LOCOMOTION • Due 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.
SWIM BLADDER & GILLS • Swim/air bladder-gas filled sac that can be used for buoyancy, sound & protection. • Gills extract Oxygen efficiently from water. • Blood flow in the filaments is opposite the flow of water resulting in the greatest amount of gas exchange!
LATERAL LINE • Lateral 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 some point in their life) • Schooling helps with mating +Protection.
REPRODUCTION • Oviparous-both sexes spawn & eggs are fertilized externally. • Ovoviviparous-some incubate the eggs, internal fert., no nourishment, some species actually bear their young living! • Viviparous-internal, nourishment, all species bear their young living.
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
Anadromous- Breed in freshwater but live in salt • Atlantic Salmon makes multiple trips in its lifetime • Pacific Salmon only once