1 / 82

The Fishes: Vertebrate Success in Water

The Fishes: Vertebrate Success in Water. The Fishes: Vertebrate Success in Water. Chapter 18. Chapter 18. Fish vs. Fishes. “The ocean is full of fishes.”. “This tank is full of fish.”. Phylum Chordata - notochord, pharyngeal slits, dorsal tubular nerve cord, postanal tail.

tate-dyer
Download Presentation

The Fishes: Vertebrate Success in Water

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. The Fishes:Vertebrate Success in Water The Fishes:Vertebrate Success in Water Chapter 18 Chapter 18

  2. Fish vs. Fishes “The ocean is full of fishes.” “This tank is full of fish.”

  3. Phylum Chordata- notochord, pharyngeal slits, dorsal tubular nerve cord, postanal tail. • Group Craniata: skull surrounds brain, olfactory organs, eyes, and inner • Subphylum Hyperotreti- fishlike; skull cartilaginous bars; jawless; slime glands; Hagfish • Subphylum Vertebrata- vertebrate surrounds nerve cord

  4. Evolutionary Evidence • Hagfish are the most primitive living craniates. • 2 Key craniate characteristics is: the brain and bone • 530 million years ago possible fossil with brain • 500 million years ago bone well developed in group of fishes called Ostracoderms (bony armor) The first vertebrates were fishlike animals that appeared more than 500 million years ago. The internal skeletons of these jawless creatures were cartilaginous and rarely preserved. Ostracoderms had bony external shields that covered the head and most of the trunk.

  5. Evolutionary Evidence • First vertebrates probably marine • Vertebrates did adapt to freshwater and much of the evolution of fish occurred there. • Early vertebrate evolution involved the movement of fishes back and forth between marine and freshwater environments.

  6. Evolutionary Evidence The importance of freshwater in the evolution of fishes is evidenced by the fact that over 41% of all fish species are found in freshwater, even though freshwater habitats represent only a small percentage (0.0093% by volume) of the earth’s water resources.

  7. Subphylum Hyperotreti The Hagfish • Head-supported by cartilaginous bars • Brain- enclosed in fibrous sheath Intro video to Hagfish

  8. Subphylum Hyperotreti • Lack vertebrae • Retain notochord (axial supportive structure) • 4 pairs of sensory tentacles surrounding their mouths • Ventrolateral slime glands See the copious amounts of slime See hagfish make a knot

  9. Subphylum Hyperotreti • Found: cold water marine habitats • Feed on: soft bodied invertebrates or scavenge on dead or dying fish • To provide leverage, the hagfish ties a knot in its tail and passes it forward to press against the prey Eating on dead whale carcass

  10. Subphylum Vertebrata • Vertebrae that surrounds a nerve cord and serves as the primary axial support • Most are vertebrates are members of the superclass Gnathostomata • Jawed fishes • Tetrapods

  11. Ostracoderms • Extinct agnathans (without jaws) that belong to several classes. • Bottom dwellers and very sluggish • Filter feeders • Bony armor • Bony plates around mouth to act like a jaw

  12. Class Cephalaspidomorphi • Cephala-head, aspidos- shield, morphe-form Lampreys -agnathans

  13. Class Cephalaspidomorphi • Live in both marine and freshwater • Larva filter feeders • Adults prey on fish • Mouth –suckerlike with lips for attachment functions

  14. Class Cephalaspidomorphi • Attach to prey with lips and teeth • Use tongues to rasp away scales

  15. Class Cephalaspidomorphi • Salivary glands with anticoagulant; feed on blood

  16. Class Cephalaspidomorphi • Two types: • Freshwater brook lampreys • Freshwater • Larval stage can last three years • Adults only reproduce, never leave stream, then die

  17. Class Cephalaspidomorphi • Two types: • Sea lamprey • Live in ocean or Great lakes • End of life, migrate to freshwater stream to spawn • Female attaches to a stone with mouth • Male uses his mouth and attaches to female’s head • Eggs are shed • Fertilization is external

  18. Sea lamprey Reproduction:

  19. Gnathostomata Vertebrates with jaws (evolved from anterior pair of pharyngeal arches) • Jaws importance: • More efficient gill ventilation • Capture and ingestion of a variety of food sources

  20. Gnathostomata • Paired appendages importance: • Decease rolling during locomation • Controls tilt or pitch • Lateral steering

  21. Body parts of fish Get ready to draw a fish!!!

  22. 1. Caudal fin - tail fin Used for forward motion and acceleration

  23. 2. Dorsal fin & 3. Anal fin Singular fins Used to prevent rolling/tipping

  24. 4. Pectoral fin & 5. Pelvic fin Paired fins (left & right) Used to balance, stop & turn

  25. 6. Spines Used for protection Some contain poison sacs

  26. 7. Operculum Covers & protects gills Not found in sharks

  27. 8. Lateral line Sensory canals used to detect changes in water pressure around the fish (similar to human ear)

  28. Gnathostomata • Jaws and appendages: • Increase predatory lifestyles • Ability to feed efficiently: • Increase offspring • Exploit new habitats

  29. Gnathostomata • Two Classes: • Class Chondrichthyes- sharks, skates, rays, ratfish • Class Osteichthyes- bony fish

  30. Class Chondrichthyes Chondro- cartilage, ichthyes- fish • Sharks, skates, rays, ratfish • Carnivores or scavengers • Most marine

  31. Dwarf Lantern Shark Guitarfish

  32. Class Chondrichthyes • Biting mouthparts • Paired appendages • Placoid scales (gives skin tough, sandpaper texture) • Cartilaginous endoskeleton These sharply pointed placoid scales are also known as dermal teeth or denticles. They give the shark’s skin the feel of sandpaper. The tip of each scale is made of dentine overlayed with dental enamel. The lower part of each scale is made of bone. The scales disrupt turbulence over the skin, considerably reducing the drag on the shark as it swims.

  33. Class Chondrichthyes Subclass Elasmobranchii elasmos- plate metal, branchia- gills Sharks, skates, rays 820 species Placoid scales

  34. Subclass Elasmobranchii • Shark teeth are modified placoid scales • Rows of teeth • As outer teeth wear out, newer teeth move into position from inside jaw and replaces them How many teeth do sharks have?

  35. Subclass Elasmobranchii • Largest living sharks? • Filter feeders- whale shark • Pharyngeal-arch modifications that strain plankton

  36. http://video.nationalgeographic.com/video/animals/fish-animals/sharks-and-rays/deadliest-hammerhead-shark/ -hammerhead • http://www.youtube.com/watch?v=eh_HUIJkRzU – Goblin shark

  37. Subclass Elasmobranchii • Fiercest most feared sharks? • Great white shark Great White Shark (Carcharodoncarcharias),South Africa, Atlantic Ocean.

  38. Subclass Elasmobranchii Skates and rays Life on the ocean floor in shallow waters Wing like appendages Camouflage The little skate settles on the ocean floor where it blends in with the light colored sand. It can easily surprise any prey while waiting in this position.

  39. Short-nose Electric Ray

  40. http://www.flmnh.ufl.edu/fish/education/questions/raybasics.html skates vs rays • http://www.youtube.com/watch?v=6rThDoJyjG0 – Spotted Eagle Ray • http://www.cnn.com/2011/US/03/29/florida.ray.tourist/index.html ray news story

  41. Subclass Holocephali Holo- whole, cephal-head • Ratfish • Lack scales • Gill covered with operculum • Teeth large plates for crushing

  42. Class Osteichthyes • Osteo- bone, ichthyes- fish • Bone in skeleton and/or scales • Bony operculum covering the gill openings (few have lungs) • Swim bladder

  43. Class Osteichthyes • Subclass Sarcopterygii Sacro-flesh, pteryx- fin • Muscular lobes associated with fins • Many use lungs in gas exchange

  44. Subclass Sarcopterygii Lungfish • Live in regions where seasonal droughts are common • When water stagnates and dry up use lungs to breathe air

  45. Subclass Sarcopterygii Coelacanths • Thought to be exinct • But 1938 in South Africa, found one • In 1977 another species found off coast of Indonesia A coelacanth swimming near Sulawesi, Indonesia

  46. Subclass Sarcopterygii Osteolepiforms • Are extinct • Believed to be ancestors of ancient amphibians

  47. Subclass Actinopterygii • Actin- ray, pteryx-fin • Ray-finned fishes because their fins lack muscular lobes • Swim bladder-gas-filled sacs along the dorsal wall of the body cavity that regulates buoyancy Swim_bladder of a Rudd (Scardinius erythrophthalmus)

  48. Subclass Actinopterygii • One group is called: Chondrosteans • 25 living species today • Ancestral species had a bony skeleton but living members have a cartilaginous skeleton. • Tail with a large upper lobe.

  49. Subclass Actinopterygii Chondrosteans • Sturgeons • Live in sea and migrate into rivers to breed • Bony plates (scutes) cover anterior • Valued for their eggs-caviar (severely overfished)

More Related