phylum chordata - amphibians & reptiles

25
Phylum Chordata Superclass Vertebrata Class Amphibia (salamanders, newts, frogs and toads)

Upload: sws

Post on 11-May-2015

5.539 views

Category:

Education


1 download

TRANSCRIPT

Page 1: Phylum Chordata - Amphibians & Reptiles

Phylum Chordata

Superclass VertebrataClass Amphibia

(salamanders, newts, frogs and toads)

Page 2: Phylum Chordata - Amphibians & Reptiles

Class Amphibia• These were first land vertebrate

• Endoskeleton (the rest being made of cartilage), complete gut, closed circulatory system.

• The skin is almost always moist and is water permeable. It lacks scales, and can be smooth (frogs) or bumpy (toads).

• Wide variety of shapes, sizes and colors, – some of the most poisonous vertebrates are amphibians

(arrow-point frogs).

There are approximately 3000 species in 3 orders:Gymnophiona (caecilians, legless amphibians) 160 spCaudata (salamanders, newts) 300 spAnura (frogs, toads) 2500 sp

Boophis viridis

Page 3: Phylum Chordata - Amphibians & Reptiles

• Viviparous – some give birth to live young• Oviparous (egg-laying) – some lay eggs

– will lay several hundred small, round eggs covered in a gelatinous mass.

• Eggs laid in water, either a pond or puddle or pool of water in a leaf.

• Some species carry the eggs in their belly, and hatch inside of the mother.

Page 4: Phylum Chordata - Amphibians & Reptiles

Life cycle

Metamorphosis!!!

Page 5: Phylum Chordata - Amphibians & Reptiles

• They all have three-chambered hearts

Page 6: Phylum Chordata - Amphibians & Reptiles

Respiratory System

Juvenile forms - gills, either internal or external, (for breathing underwater).

• Adult form - lungs. • + Water-permeable skin

which allows oxygen to diffuse through it, so they can "breathe" through their skin.

“Lungless” species found in a clear, cold-water stream on the island of Borneo in Indonesia

Page 7: Phylum Chordata - Amphibians & Reptiles

• There are separate sexes

• Some species can change gender depending on the circumstances.– Due to over farming and

pesticides, researchers are finding fewer males.

• Most vulnerable vertebrates due to reliance on the environment.

Page 8: Phylum Chordata - Amphibians & Reptiles

Caecilians• Inhabit the wet tropical regions of south

America, Africa and south east Asia.• Lack limbs but possess a retractable

sensory tentacle. • Have a burrowing lifestyle. • The skin of one African species is fat and

nutrient-rich, so the larvae peel this skin off the parent and eat it.

• Oviviparous

Page 9: Phylum Chordata - Amphibians & Reptiles

Salamanders

• Capable of regenerating lost limbs, as well as other body parts.

• Sticky tongue which adheres to the prey

• Defense– Tail autotomy to escape predators. The

tail will drop off and wriggle around for a little while.

– They can also produce a white milky substance that is poisonous

Page 10: Phylum Chordata - Amphibians & Reptiles

Texas Blind Salamander

Vestigial Eyes –

Left over, non-functional eyes

Page 11: Phylum Chordata - Amphibians & Reptiles

Axolotl

Mexican Walking Fish

Page 12: Phylum Chordata - Amphibians & Reptiles

Newts• Produce toxins in their skin as a

defense mechanism against predators.

• Taricha granulosa, “rough-skinned” newts of western North America are particularly toxic producing more than enough tetrodotoxin to kill an adult human.

• Some Native Americans of the Pacific Northwest used the toxin to poison their enemies.

However, the toxins are only dangerous if ingested.

Page 13: Phylum Chordata - Amphibians & Reptiles

Frogs

Poison dart frogs

Page 14: Phylum Chordata - Amphibians & Reptiles

Toads

Bufo Bufo –

the common toad

Page 15: Phylum Chordata - Amphibians & Reptiles

Phylum Chordata

Superclass Vertebrata

Class Reptilia

Crocodiles, alligators, lizards, snakes, turtles & tortoises

Page 16: Phylum Chordata - Amphibians & Reptiles

Class Reptilia• Air-breathing, ectothermic (cold-blooded) vertebrates• Having skin covered in scales, adaptation• Lay eggs with shells, adaptation

• Inhabit every continent with the exception of Antarctica. • Reptiles originated around 320-310 million years ago during

the Carboniferous period,

• Three main living orders:– Crocodilia (crocodiles, gavials, caimans, and alligators): 23 species– Squamata (lizards, snakes, and worm lizards): approximately 9,150

species– Testudines (turtles, terrapins and tortoises): over 300 species

Page 17: Phylum Chordata - Amphibians & Reptiles
Page 18: Phylum Chordata - Amphibians & Reptiles

• Species that lay eggs with shells.

• “Amniotes” – tetrapods that lay a terrestrially adapted egg.

Page 19: Phylum Chordata - Amphibians & Reptiles

Crocodilia

crocodiles

alligators

Page 20: Phylum Chordata - Amphibians & Reptiles

Squamata

Page 22: Phylum Chordata - Amphibians & Reptiles

Infrared Sensing - Thermoreception

http://www.youtube.com/watch?v=lySW2-eYilg

Page 23: Phylum Chordata - Amphibians & Reptiles
Page 24: Phylum Chordata - Amphibians & Reptiles

Testudines

Page 25: Phylum Chordata - Amphibians & Reptiles

• http://www.youtube.com/watch?v=vfYSg2S5ljs