Fish By Mr. “I love fish” Chapman

Fish History First fossils were found about 425-500 MYA First fish fossils came from an Ostracoderm. “Plate skin”

Ostracoderm Poorly developed fins and no jaw. First animal with a backbone.

More Info Ostracoderms become extinct and two groups of fish evolved from them.

Placoderms First group was the Placoderms, which appeared about 395 MYA. They had thick bony plates with paired fins. Their upper jaw was fused to the skull and the lower jaw was hinged to the skull.

Placoderms

Placoderms Placoderms became extinct about 396 MYA Class: Chondrichthyes evolved from Placoderms. Chondrichthyes Chondra means ”cartilage” Ichthyic means ‘fish” Cartilaginous fish: 350 species (most sharks) Ex. Sharks, Rays, Skates

Info The 2nd group to evolve from Ostracoderms was the Acanthodians. The appeared about 410 MYA First fish with both jaws are movable

Acanthodians Acanthodians evolved into Class: Osteichthyes. Osteichthyes “Bony Fish”

Osteichthyes By Mr. “Cherry Jelly” Chapman

Osteichthyes There are approximately 25,000 species of bony fishes worldwide. If all of the living species in all of the other vertebrate classes were added up, the sum total would be less than the number of bony fishes.

Fish Characteristics All bony fish have: Bony skeleton 2 chamber heart Cold blooded Some type of scales Lateral line

Bony Fish Primitive bony fishes had/have heavy scales, their paired fins are far apart on the body. Air bladders functioned as lungs.

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Fish are divided into 2 groups: Fish with spines in their fins are called Ray-finned fish. Fish w/o spines are called Lobed-finned fish.

Scales Scales – thin bony plates that overlap each other and provide protection. Glands on the scales produce a slimy mucus, which protects them from bacteria.

Types of Scales There are four types of scales: 1. Placoid – type of scales on sharks 2. Ganoid – scales are connected to each other (like armor). Ex. Is a Gar

Scales 3. Cycloid – have smooth surfaces and edges. 4. Ctenoid – are like cycloid scales, but have sharp/rough edges that stick out.

Assignment In groups of 2, you need to find two species of fish and provide the following information: Family name The common name and scientific name. Picture of the fish Where it natural lives, types of food it eats, how big it gets, description of fish (coloration). What type of aquarium would it live in (size and other fish). Two interesting facts about the fish.

Resources In the book from pages 345-372 http://www.aquariumfish.net Go to Google.com and type the name of the fish (scientific name will work best).