logging in or signing up Amphibians aSGuest76550 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 445 Category: Science & Tech.. License: Some Rights Reserved Like it (0) Dislike it (0) Added: November 25, 2010 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Amphibians : 02 Sept. 2010 Amphibians.ppt 1 Amphibians Class Amphibians : 02 Sept. 2010 Amphibians.ppt 2 Class Amphibians Old group of tetrapod (4-footed) vertebrates, older than reptiles. Origin in mid-Paleozoic Class Amphibians : 02 Sept. 2010 Amphibians.ppt 3 Class Amphibians Less well adapted to terrestrial environment Smooth skin, no scales (no keratin ?) External fertilization depend on water for mating; sperm and eggs released together into water No embryonic membranes, Egg must stay moist usually in water, rarely in moist soil Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 4 Amphibian Life Cycle Larvae (immature form, tadpoles) hatch in water, Gills for gas exchange. Tail Metamorphosis to adult form growth of limbs development of lungs and loss of gills loss of tail in frogs, toads Adult usually terrestrial, some exceptions Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 5 Amphibian Life Cycle Live in two habitats exploit two sets of resources Produce large numbers of eggs No parental care, tadpoles “on their own” Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 6 Amphibian Life Cycle Advantages Produce abundant offspring (less investment of matter, energy in each) At least a few likely to survive. Disadvantages Each egg/tadpole has small chance of survival wasteful dependent on water, few can live far from surface water Class Amphibians : 02 Sept. 2010 Amphibians.ppt 7 Class Amphibians Order Salamanders Primitive form with four equal legs Retain tail Class Amphibians : 02 Sept. 2010 Amphibians.ppt 8 Class Amphibians Order Frogs Tail lost in metamorphosis Hind legs enlarged, hopping or leaping locomotion Class Amphibians : 02 Sept. 2010 Amphibians.ppt 9 Class Amphibians Order Caecilians legless, burrowing (resemble earthworms, but with skull & backbone) tropical AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 10 AMPHIBIANS as Environmental Indicators Decline in frog, toad, and salamander populations reported, world wide. Is a worldwide decline real ? If so, what cause or causes of decline (hypotheses): AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 11 AMPHIBIANS as Environmental Indicators H1: Water pollution Industrial waste, toxins Acids, alkalai, PCBs, etc. Agricultural runoff pesticides, excess fertilizers Sewage AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 12 AMPHIBIANS as Environmental Indicators H2: Global warming (with changes in rainfall) ? cloud forest zones on tropical mountains moved up above mountains; loss of habitat. AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 13 AMPHIBIANS as Environmental Indicators H3: UV radiation from thinning of ozone layer More UV from sun reaching surface of Earth Amphibian embryos in shallow water killed by UV Genetic mutations make survivors less viable, less fecund. AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 14 AMPHIBIANS as Environmental Indicators H4: Parasites ? bird parasites use tadpoles/frogs as hosts for parasite larvae malformed frogs, extra or missing limbs, etc. malformed frogs easy prey for herons, cranes, etc. Birds, frogs, & parasites concentrated in shrinking wetland habitats AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 15 AMPHIBIANS as Environmental Indicators Combination of effects ? Water pollution, Global warming, UV radiation from thinning of ozone layer, and Parasites, etc. Common cause ? You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Amphibians aSGuest76550 Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 445 Category: Science & Tech.. License: Some Rights Reserved Like it (0) Dislike it (0) Added: November 25, 2010 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Amphibians : 02 Sept. 2010 Amphibians.ppt 1 Amphibians Class Amphibians : 02 Sept. 2010 Amphibians.ppt 2 Class Amphibians Old group of tetrapod (4-footed) vertebrates, older than reptiles. Origin in mid-Paleozoic Class Amphibians : 02 Sept. 2010 Amphibians.ppt 3 Class Amphibians Less well adapted to terrestrial environment Smooth skin, no scales (no keratin ?) External fertilization depend on water for mating; sperm and eggs released together into water No embryonic membranes, Egg must stay moist usually in water, rarely in moist soil Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 4 Amphibian Life Cycle Larvae (immature form, tadpoles) hatch in water, Gills for gas exchange. Tail Metamorphosis to adult form growth of limbs development of lungs and loss of gills loss of tail in frogs, toads Adult usually terrestrial, some exceptions Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 5 Amphibian Life Cycle Live in two habitats exploit two sets of resources Produce large numbers of eggs No parental care, tadpoles “on their own” Amphibian Life Cycle : 02 Sept. 2010 Amphibians.ppt 6 Amphibian Life Cycle Advantages Produce abundant offspring (less investment of matter, energy in each) At least a few likely to survive. Disadvantages Each egg/tadpole has small chance of survival wasteful dependent on water, few can live far from surface water Class Amphibians : 02 Sept. 2010 Amphibians.ppt 7 Class Amphibians Order Salamanders Primitive form with four equal legs Retain tail Class Amphibians : 02 Sept. 2010 Amphibians.ppt 8 Class Amphibians Order Frogs Tail lost in metamorphosis Hind legs enlarged, hopping or leaping locomotion Class Amphibians : 02 Sept. 2010 Amphibians.ppt 9 Class Amphibians Order Caecilians legless, burrowing (resemble earthworms, but with skull & backbone) tropical AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 10 AMPHIBIANS as Environmental Indicators Decline in frog, toad, and salamander populations reported, world wide. Is a worldwide decline real ? If so, what cause or causes of decline (hypotheses): AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 11 AMPHIBIANS as Environmental Indicators H1: Water pollution Industrial waste, toxins Acids, alkalai, PCBs, etc. Agricultural runoff pesticides, excess fertilizers Sewage AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 12 AMPHIBIANS as Environmental Indicators H2: Global warming (with changes in rainfall) ? cloud forest zones on tropical mountains moved up above mountains; loss of habitat. AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 13 AMPHIBIANS as Environmental Indicators H3: UV radiation from thinning of ozone layer More UV from sun reaching surface of Earth Amphibian embryos in shallow water killed by UV Genetic mutations make survivors less viable, less fecund. AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 14 AMPHIBIANS as Environmental Indicators H4: Parasites ? bird parasites use tadpoles/frogs as hosts for parasite larvae malformed frogs, extra or missing limbs, etc. malformed frogs easy prey for herons, cranes, etc. Birds, frogs, & parasites concentrated in shrinking wetland habitats AMPHIBIANS as Environmental Indicators : 02 Sept. 2010 Amphibians.ppt 15 AMPHIBIANS as Environmental Indicators Combination of effects ? Water pollution, Global warming, UV radiation from thinning of ozone layer, and Parasites, etc. Common cause ?