FC: FISHES | Jose Eduardo Villarreal
1: Introduction | Fishes are aquatic vertebrates most fishes have paired fins, scales and gills.
2: Jawless fish
3: Sharks and Their Relatives | Bony Fishes
4: Jawless-agnatha | -They have no true jaw or teeth -skeletons made up of fibers and cartilage -lack a vertebrae -filter feeders as larvae and parasites -worm-like bodies and 4 or 6 tentacles around their mouth
5: Sharks and Their Relatives-Chondrichthyes | -contains sharks, rays, skates and few uncommon fishes like sawfishes and chimaeras -skeletons entirely of cartilage -scales make up skin and they have large curved tails, torpedo shaped bodies and pointed snouts -they have thousands of teeth and they go through 20,000 teeth in its lifetime -most sharks don't attack people -skates and rays feed on bottom dwelling using their mouth as vacuums
6: Bony Fishes Osteichthyes | -skeletons are made up of hard, calcified tissue called bones -almost all bony fishes belong to a huge group called ray-fined fishes -only 7 living species of bony fishes are not classified as ray-finned -they are classified under lobe-finned which is a subclass -lungfishes live in fresh water while coelacanth live in salt water -bones are joint like arms and legs of land vertebrates
8: Ecology | Most fishes live their lives in fresh water or saltwater. Those who can not live in salt water s because their kidneys can not maintain internal water balance in this environment. Ocean fishes can not tolerate water with low concentration of salt. Some species can move from salt to fresh water and from fresh to saltwater. There are some fishes that are born in fresh water but migrate to salt water to live and then go back to reproduce.