Transcript Chapter 40 Fish

Fish
Kindgom Animalia
Phylum Chordata
Subphylum Vertebrata
Characteristics of all Vertebrates
All vertebrates have the following:
• Vertebrae surrounds dorsal nerve cords
• Cranium/skull
• Endoskeleton made of bone or cartilage
All vertebrates have bilateral symmetry, endoskeletons,
closed circulatory system, nervous system w/complex
brain & sensory organs and efficient respiratory
systems.
Three Types of Fertilization
• Oviparous - to lay eggs w/external
fertilization w/no parental care after birth
• Ovoviviparous-to lay eggs w/internal
fertilization w/nourishment from yolk not
mother.
• Viviparous-to bear live young w/internal
fertilization w/nourishment from mother
after birth.
Characteristics of Fish
• Use gills to breath
• Two-chambered heart
• Reproduce sexually either oviparous or some species
viviparous.
• External fertilization is called spawning.
• Paired fins for balance, swimming, and steering.
• Highly develop sensory system – lateral line system
used to detect movement and vibrations in the water.
• Scales – thin bony plates formed from skin.
• Separated vertebrate for flexiblity
• Swim bladder – internal sac below backbone used for
buoyancy.
Class Agnatha
• Lampreys & Hagfish which are jawless,
have eel-like bodies, no scales, cartilage
skeleton & unpaired fins
• Hagfish are bottom dwellers eating dead or
dying fish, ties body into knots & secretes a
bad taste to predators.
• Lampreys are both free-living & parasites,
scrape holes in the sides of other fish.
http://www.gen.umn.edu/research/fish/fishes/I_castaneus.jpg
Class Osteichthyes
• Bony fish - eels, perch, trout, salmon,
guppies, lungfish, coelacanth, herring
• Lateral Line – a distinct line that runs down
side of most fish.
• Characteristics
– skeleton made of bone
– lungs or gills & swim bladder
– scales - cover & protect body
Two types of Osteichthyes
• Lobe-finned fishfleshy fins
• seven species
– six are lungfish
– one is coelacanth,
thought to be extinct
http://www.seychelles.net/divesey/images/Coelacanth.jpg
Two types of Osteichthyes
• Ray finned fish - bony
fins called rays
• 5 types of fins-see
picture
• Operculum - gill
covering
• Oviparous-large
number of eggs
“spawning”
http://www.biologycorner.com/resources/fish_fins.gif
Inner Workings of Bony fish
• Digestive tract - mouth-pharynx-esophagusstomach-intestines-absorption-anus
• Closed circulatory system w/2 chambered heart
• Gills for gas exchange & swim bladder for
buoyancy.
• Use of kidneys to filter blood excrete urine
• Brain w/spinal cord
– cerebrum-sensory information
– cerebullum-motor output
– medulla oblongata-involuntary body functions
Class Chondrichthyes
• Cartilaginous fishsharks, rays, skates
• Most are carnivores,
some scavengers
• Endoskeleton of
cartilage
• Skin covered w/placoid
scales feels like
sandpaper
• Mostly viviparous
Class Chondrichthyes
• Sharks have 6-20 rows of
teeth
• Use well developed sense
of smell
• Well developed lateral line
• Largest brain for their size
• Extremely sensitive to
electrical fields
Amphibians
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Amphibia
Class Amphibia
• In Greek, amphibian
means “double life”.
• This class includes
frogs, toads,
salamanders,
caecilians
http://allaboutfrogs.org/gallery/photos/images/thumbs/lilfrg1.jpg
Common Characteristics of Class
Amphibia
•
•
•
•
•
Two part life -aquatic larva / terrestrial adult
Moist skin w/no scales
Webbed, clawless feet (if feet are present)
Gills, lungs & skin used for respiration
No shells on eggs w/external fertilization, must
have moisture for eggs.
• Two part function of the skin is for respiration &
protection
• Ectothermic- gets heat from the environment
Amphibian Systems
• Adult amphibians have a two-loop
circulatory system w/a 3-chambered heart.
Tadpoles have a single-loop w/a 2chambered heart.
• Kidneys are used to excrete nitrogen waste.
• Food passage: pharynx-esophagus-stomachliver-gall bladder-intestines-cloaca
• The intestines are held together by the
mesentery.
Amphibian Senses
• Well developed nervous system
– Cerebullum- muscular coordination
– Cerebrum – behavior & learning
– Medulla oblongata – involuntary organ
functions
• Nictitating membrane is a transparent eye
covering
• Tympanic membrane is the eardrum.
Order Anura
• Includes frogs & toads found virtually worldwide
• Toads have rough, bumpy skin & live near water
• Frogs have smooth, moist skin & live in or near
water
• The larvae are tadpoles for both. They go through
metamorphosis to change.
• Oviparous w/external fertilization
• Carnivores as adults, herbivores as larvae
http://allaboutfrogs.org/gallery/photos/redeyes/giantr.gif
http://allaboutfrogs.org/gallery/photos/images/castro.jpg
Order Caudata
• Salamanders –elongated bodies, long tails,
moist skin.
• Internal fertilization
• Keep tail as adult and are carnivores in both
parts of their life cycle
• Mudpuppies & axolotl never lose gills &
remain in water entire life.
http://www.mister-toad.com/photos/salamander/Amaculatummetamorph.jpg
Order Apoda
• Caecilians – legless
amphibians that
resemble snakes
• Live in tropical
regions
• All have internal
fertilization
• Small eyes and are
often blind.
Photo by Bernhard Schuster of Germany