Diversity Of Fish And Amphibians

Diversity of Fish and Amphibians Jeremiah was a bullfrog…..Joy to the fishes in the deep blue sea……

Vertebrates
Phylum Chordata-named for a structure that is found in all chordate embryos

Characteristics of Vertebrates
Notochord
Hollow nerve cord along the dorsal (back) side
Pharyngeal slits
Tail that extends beyond the anus.

4 Characteristics of Vertebrates
Notochord-flexible rod that extends through much of the length of the body
Hollow nerve chord-develops into the brain and the spinal chord, non-chordates have either no nerve chord or a solid nerve cord along the ventral side (front)

Characteristics of Vertebrates
Pharyngeal gill slits- some keep them and use them for gills and when they aren’t used, they develop into jaw support, hearing and other functions

Two Groups of Invertebrate Chordates
Tunicates or sea squirts are marine animals that are sessile and filter seawater through their pharyngeal slits.
Adults only have 1 of the 4 chordate features but the larva have all 4 features.
Lancelets are blade-like chordates that resemble tunicate larva and have all four characteristics.

Tunicates

Lancelets

Vocab
Vertebrae-enclosed nerve cord, composes the backbone
Endoskeleton-skeleton inside the body, come are made of bone or cartilage, it has living cells that grow and get larger unlike arthropod skeletons that are molted.

Vertebrates
Almost all vertebrates have a hinged jaw which enable the vertebrate to capture and eat prey.
Hagfish and lampreys are most closely related to ancestral vertebrates because they are aquatic and lack hinged jaws and paired limbs.
Hagfish are further primitive because they lack a vertebrae but are supported by an adult version of a notochord.
Hinged jaws are believed to involved from skeletal supports of pharyngeal gill slits.

Class Agnatha (Jawless Fishes) Lamprey

Class Agnatha (Jawless Fishes) Hagfish

Tetrapods
Tetrapods-4 footed, 2 sets of paired limbs for support, some tetrapods have no limbs but evolved from limbed ancestors

Class Chrondrichthyes
Nearly all sharks live I marine habitats except the bull shark which can live in freshwater.
Fins are not very movable so sharks aren’t very maneuverable.
Continual swimming is necessary to keep from sinking but sometimes they rest on the sea floor and use their jaw muscles to pump water over their gills.
Sharks also have a sensitive lateral line system which is a row of sensory organs running along the side of their body.
Sharks can also detect electric fields and track prey this way.
Sharks also have skin made of denticles which are like small teeth.

Class Chondricthyes (cartilaginous fishes) sharks

Rays and Skates
Rays and skates are closely sharks but are adapted to a very different lifestyle.
Rays and skates are bottom dwellers that feed on the ocean floor or cruise the open ocean feeding on plankton.
Front fins are enlarged and help the animal “fly” through the water like a bird.
Many rays have poisonous barbs on their tails for defense.
The largest rays are the manta rays.

Class Chondricthyes Rays

Class Chondricthyes Skates

Class Chondricthyes The chimera, a living fossil!

Bony Fishes
Bony fish are divided into 3 classes.
All bony fish have a relatively stiff skeleton reinforced by hard calcium compounds.
On each side of the head of bony fish, a protective flap called the operculum covers a chamber housing the gills and allows water to pump even though the fish isn’t moving.
Bony fish also have a lateral line system and flattened stiff scales to cover the skin and glands to secrete a slimy mucus to help fish glide easily through the water.

Bony fish
There are two key features bony fish have.
Bony fish have air sacs and a 2 chambered heart.
A swim bladder is an air sac that functions in making the fish more buoyant and aids in hearing.
The 2 chambered heart is not very efficient but works for fish because they have a slow metabolism.
It is a single circuit pathway for blood flow that delivers oxygen to tissues very slowly.

Strange fish from the ray-finned fish family

Ray-finned fish
There are more than 20,000 species of these fish.
They are named for the thin flexible fins supported by bony rays or spines and these fish also have a swim bladder.

Lobe-finned fish: The coelacanth

Lobe-finned fishes
Have muscular fins supported by stout bones and are not common today and are known mainly from the fossil record.
The only surviving group is the coelacanths of Madagascar and Indonesia. (Once believed to be extinct.)

Lungfish

Lungfish
Lungfishes are found on continents in the southern hemisphere.
The air bladder functions as a lung so it can breathe out of water.
Lungfish also have gills to take oxygen from water.
Current research indicates the lungfish may be closely related to tetrapods.

Origin of Tetrapods
Amphibians are tetrapods and were the first vertebrates with adaptations for living on land.
The earliest tetrapods lived in shallow, aquatic habitats about 400-350 million years ago during the Devonian period.
Acanthostega was an early tetrapod that had limbs like those found in reptiles and mammals including humans.

The Origin of Tetrapods
Amphibians live part of their life cycle in water and part on land.
The larval stage is in water while the adult stage is terrestrial.
Many adults have lungs, smooth moist skin and lack scales.
Tadpoles are legless larva that have gills, a lateral line system and a long finned tail like fish.
There is great diversity and some amphibians have poison glands that aid in defense.
An amphibian heart has a 3 chambered which is more efficient than a 2 chambered heart of a fish.

Frogs and Toads (Order Anura)
4,200 known species
Bulging eyes
Pair of external eardrum called a typanum
Webbed feet
No tail
Strong hind legs
Smooth moist skin
Loud mating calls
Toad is a term generally used for frogs that have rough skin and live in terrestrial environments

Frogs and Toads

Salamanders and Newts (Order Urodela)
500 species
Have a tail
Closely related to each other
Bodies are long and slender
Resembled early tetrapods
Some terrestrial species do not have lungs but exchange oxygen and carbon dioxide through their skin and mouth lining

Salamanders and Newts

Salamanders and Newts American Hellbender Japanese Giant Salamander

Caecilians (Order Apoda)
150 species
Legless
Nearly blind
Inhabit burrows
Evolved from a legged ancestor
A few South American species have adapted to freshwater ponds and streams

Caecilians

Chordates Vertebrate Invertebrate 4 characteristics Tunicates Lancelets larva notochord Hollow nerve cord dorsal side Pharyngeal slits Tail that extend beyond the anus

Fish Class Chondrichthyes Bony fish Skeleton hardened With calcium

Class Chondrichthyes Sharks and rays Cartilaginous skeleton

Bony fish Ray-finned fish Lobe-finned fish Lungfish Class Actinopterygii Class Actinista Class Dipnoi Most fish types coelocanths Ancestors to tetrapods Can breathe air

Amphibians Order Anura Order Urodela Order Apoda

Order Anura Frogs Toads jump walk Moist skin Rough, dry skin Partially aquatic Usually terrestrial Poison glands

Order Urodela salamanders Newts terrestrial aquatic tail tail Sometimes have External gills

Order Apoda caecilians legless tropical

Diversity Of Fish And Amphibians

by Tia Hohler on Nov 30, 2008

Accessibility

Categories

Tags

Upload Details

Usage Rights

3 Embeds 13

Statistics

Diversity Of Fish And Amphibians — Presentation Transcript

http://www.slideshare.net	7
http://www.allzoon.com	5
http://webcache.googleusercontent.com	1