1 / 15

Ichthyology

Ichthyology. The study of fishes. Over half of all vertebrates are fishes! Fishes have the following 5 characteristics in common: Vertebral column : internal skeleton spine surrounding the dorsal nerve cord

harva
Download Presentation

Ichthyology

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. Ichthyology The study of fishes

  2. Over half of all vertebrates are fishes! • Fishes have the following 5 characteristics in common: • Vertebral column: internal skeleton spine surrounding the dorsal nerve cord • Jaws and paired appendages: all fish except lampreys and hagfishes have both. Jaws allow fishes to eat things bigger then their mouths • Internal Gills: used for respiration • Single-loop blood circulation: blood goes from heart to gills to rest of body and back to heart • Nutritional deficiencies: unable to make certain amino acids and must consume them (just like all of their vertebrate descendants!)

  3. Evolution of the jaw: • Fundamentally important evolutionary advance • Evolved from the most anterior of a series of gill arches

  4. The evolution of shark teeth: • Sharks were among the first vertebrates to develop teeth • Evolved from rough scales on the skin and are not set into the jaw like human teeth • Not firmly anchored and easily lost • A shark may loose more than 20,000 teeth in it’s lifetime

  5. The Lateral Line System: • Supplements the fish’s sense of hearing (yes, fish have ears too) • Series of canals running length of the body • Within these canals are hair cells with cilia that detect water movement • This what enables the fish to detect prey and swim in synchrony with it’s school

  6. The Swim Bladder • Gas-filled sac that allows bony fish to regulate their buoyant density and adjust their depth effortlessly • Organs are filled and drained of nitrogen and oxygen internally

  7. Gills! • Fish allow water to flow over the gills for gas exchange • Bony fish have an operculum • Hard plate covering the gills • Bony fish can pump water over their gills, sharks can not

  8. Fish are divided into 7 classes: • Sarcopterygii, lobe-finned fishes • Actinopterygii, Ray-finned fishes • Chondrichthyes, Sharks and rays • Cephalaspidomorphi, Lampreys • Myxini, Hagfishes • Placodermi, Armored fishes • Acanthodii & Ostracoderms, Spiny fishes

  9. Class Myxini: The Hagfishes http://www.youtube.com/watch?v=Bb2EOP3ohnE&feature=player_embedded

  10. Cephalaspidomorphi: The Lampreys!

  11. Sarcopterygii: Lobe-finned Fishes!

  12. Placodermii: Armored Fishes! (extinct)

  13. Chondrichthyes: The Sharks and Rays!

  14. Actinopterygii: The Ray-Finned Fishes!

More Related