Chapter 13 – Vertebrate Animals 13.1 13.2 13.3 13.4 Vertebrate Animals w/Endoskeletons Amphibians and Reptiles Birds Mammal’s Environments 13.1 Vertebrates have Endoskeletons • Vertebrates = fish, frogs, snakes, birds, dogs, humans, etc. • Vertebrates = animals with backbones • Also have: muscles, digestive, respiratory, circulatory, and nervous system w/sensory organs • Endoskeleton = internal support system that grows along with the animal – Greater flexibility & more ways to move than an exoskeleton 13.1 Vertebrae • Vertebrates are named for specialized bones called vertebrae which are located in the middle of each animal’s central body segment (aka – a backbone or spine) • They support muscles and surround the spinal cord which connects the animal’s brain to its nerves • Gills are located inside gill slits; gills filter O2 out of water and release CO2 into water 13.1 Fish • Most vertebrates are fish which are the most diverse group. • Over 20,000 species of fish live in all aquatic environments (salt/fresh) • Have adaptations for water (gill slits & gills to breathe; streamlined bodies, etc) • Fish use muscles to move; have a swim bladder for depth control; lateral line to sense vibrations. • Able to taste, smell, hear, see, etc. underwater. 13.1 Types of FISH 1. Jawless Fish – lampreys, hagfish Simpler, slender, tubelike shape & digestive system w/o stomach; teeth, but no jaw; can bite, but not chew 2. Cartilaginous Fish – sharks, rays, skates Skeletons have no hard bone, mostly cartilage (=flexible tissue) 3. Bony Fish – tuna, flounder, eel, etc. Largest fish group (96%); also have scales (=overlapping bony structures); also - jaws, teeth, fins 13.1 Reproduction & Development • Most fish reproduce sexually • In some species females “select” males as mates • Female releases eggs; male swims over & releases sperm • Eggs are then left to hatch and develop on their own in most species. • Most fish eggs are surrounded by a soft case w/yolk inside. Sometimes fish eat eggs/young • Sometimes eggs develop inside the females body & young are born live. 13.2 Amphibians & Reptiles • Not on the final-exam! 13.3 Birds • Not on the final exam 13.4 Mammals • Not on the final exam