110 likes | 145 Views
Explore the characteristics and groups of fishes and amphibians, including jawless fish, sharks, frogs, and salamanders in this educational guide. Discover fascinating facts and life cycles of these aquatic and semi-aquatic creatures.
E N D
Phylum: Chordata Vertebrates Fish and Amphibians
Vertebrate Characteristics • To be in the phylum Chordata you must have these four characteristics at some point in your development • 1. dorsal, hollow nerve cord (backbone) • 2. a notochord (most when embryos) • 3. pharyngeal pouches (turn into gills) • 4. tail that extends beyond the anus
Fishes • Fishes are aquatic vertebrates which have • Paired fins - movement • Scales – protection (can tell age of some fish by counting the rings) • Gills – exchanging oxygen and carbon dioxide
Groups of Fish • 1. Jawless Fish • no teeth or jaws • Keep notochord as adults • Many are parasites, no swim bladder • Examples – hagfish and lampreys
Groups of Fish • 2. Cartilaginous Fish • Skeleton made of cartilage • Tooth-like scales covering skin • 350 species – most are under 3 feet • Teeth are replaced when worn out – 20,000 in lifetime • Examples: sharks, rays, skates
Groups of Fish • 3. Bony Fish – called ray-finned fish • Very diverse group • Most have a swim bladder • Anadromous fish can move from salt to fresh water
Amphibians • Amphibian means double life –water and land • Larvae- use gills- live in water • Adults – use lungs – live on land • Moist skin • No scales • No claws • Tympanic membrane behind eye (ear)
Life cycle of Frogs Surinam Frog After the female lays her pea-sized eggs, the male places them on her back and pushes them into her spongy skin. The eggs incubate as mom's new skin slowly develops and covers them, keeping them safe and out of sight. They then hatch out of her back.
Groups of Amphibians 1. Salamanders • Long bodies and tails • Four legs • Carnivores • Live in moist woods • Some keep gills their entire lives
Groups of Amphibians • Frogs and Toads • Frogs – long legs for jumping and they are closely tied to water. • Toads – short legs and often live in moist woods or even deserts.
Groups of Amphibians • 3. Caecilians – legless animals that live in water or burrow in moist soil. Some feed on termites. Fish like scales in their skin.