1 / 33

MARINE FISHES

MARINE FISHES. THE FIRST VERTEBRATES. Oldest and simplest vertebrates Most abundant vertebrates Three groups of fishes Jawless fishes Cartilaginous fishes (Chondrichthyes) Bony fishes (Osteichthyes)

cruz-moore
Télécharger la présentation

MARINE FISHES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MARINE FISHES THE FIRST VERTEBRATES

  2. Oldest and simplest vertebrates • Most abundant vertebrates • Three groups of fishes • Jawless fishes • Cartilaginous fishes (Chondrichthyes) • Bony fishes (Osteichthyes) • Yes, it is FISHES- the rule is fish is for a single individual or more than one individual of the same species • FISHES- refers to more than one species

  3. Jawless fishes • Class Agnatha • Around 30 known species • Includes hagfish & lampreys • Feed by suction with aid from teeth • No fins, & lack true vertebrae; no scales • Body is elongated and cylindrical • Most primitive fishes

  4. Cartilaginous Fishes • Class Chondrichthyes • Skeleton made of cartilage • Movable jaws • Mouth ventral • Underneath the head • Paired lateral fins • Sandpaper-like skin because of Placoid Scales • Includes sharks, rays, skates, and ratfishes

  5. SHARKS • ~350 living species • Caudal Fin is Heterocercal • Upper lobe longer than lower lobe • Fusiform, or spindle-shaped bodies • Five to seven gill slits • Powerful jaws with rows of teeth that are Continuously replaced • Carnivores & Filter Feeders • Found most often in warm coastal water Most only live in marine env. Some travel upstream

  6. SKATES AND RAYS • ~450-500 known species • Dorsoventrally flattened • Demersal: fish that live on the bottom • Five ventral gill slits • Stingrays • Whip-like tail with stinging spines • Electric Rays • Electric organs on each side of head • Skates lack the stinging tail

  7. Ratfish: AKA Chimaeras • ~30 known species • Only one pair of gill slits covered by a flap of skin • Long, rat-like tail

  8. www.itsallaboutfish.co.uk/ratfish.htm

  9. Bony Fishes • Class Osteichthyes • ~23,000 known species • Skeleton made of bone • Cycloid or Ctenoid Scales • Operculum: Gill Cover • Upper & lower tail fin same size: Homocercal

  10. Homocercal tail Cycloid scales

  11. BONY FISHES

  12. Fin Rays: thin membranes supported by bony spine • Anterior, terminal mouth • More flexible jaws with teeth attached to jawbone • Swim Bladder: gas-filled sac above stomach & intestines that helps in buoyancy

  13. BIOLOGY OF FISHES

  14. BODY SHAPE • ICHTHYOLOGY- study of fish • Body shape varies with habitat and lifestyle • Fast swimmers are streamlined- like tuna, marlins, mackerels, sharks

  15. Dorsoventrally flat- skates, rays and sea moths- demersal fish (live near bottom) Dragon sea moth Image from Liveaquaria.com

  16. Laterally flattened bottom dweller fish such as flounder, halibut and sole • Born with eyes on both sides of body but as they mature, one eye migrates to the dominant side

  17. Elongated bodies such as eels- live in narrow places amongst rock and coral reef

  18. Laterally compressed bodies live around coral reefs, kelp beds etc. Butterfly fish snappers

  19. COLORATION • CHROMATOPHORES-skin cells that contain pigments; irregular in shape with branches radiating out from the center of the cell • STRUCTURAL COLORS-Colors that result when light is reflected by a particular surface • Many times caused by IRIDOPHORES- chromatophores with light-reflecting crystals

  20. Colors reflect mood • warning coloration- coloration that allows organisms to escape from predators by advertising something harmful or distasteful video • cryptic coloration-color pattern that allows an organism to blend in its surroundings- video • Disruptive coloration- a color pattern that helps break the outline of an organism Ornate cowfish Disruptive coloration

  21. COUNTERSHADING- a color pattern that results in a dark back and a light belly- most common in epipelagic fishes (surface to 200 m)

More Related