L13: Phylum Chordata - Fishes Flashcards
Identify major fish groups Understand why "fishes" are not a natural taxonomic group Describe features of fishes that are adaptive to aquatic environments Describe the lateral line system
What features aid fish in swimming in a dense environment of water
Swim bladder
Paired fins
Slime as lubricant (reduces friction when moving through water)
Less robust skeleton (no need to fight against gravity)
What is a swim bladder? Describe how it works
Like a balloon
Aids in bouyancy
Ovale removes gas from swim bladder
Gas glands adds gas from the blood to the swim bladder
In relation to the swim bladder..
Describe physoclistous condition
Present in most modern fishes
Swim bladder is disconnected from digestive system and gas enters via the blood
In relation to the swim bladder..
Describe physostomous condition
Regulation of air in the swim bladder by swallowing air
Duct that connects digestive tract to swim bladder
How many chambers are in a fish heart?
4
The efferent brachial arteries take ____ blood to _____
oxygenated; Other organs
The afferent brachial arteries take ____ blood to __
De-oxygenated; The heart/lungs
What is the operculum?
Bony plate that protects gill tissues
Can open and close
Some fish have unpaired fins - what are they
Dorsal fins
Caudal fin (tail fin)
Anal fin (only in some)
Describe Ganoid fish scales
Mainly in primitive fish & sturgeons
Heavy and thick
What are the two bony ridge scales found in modern fishes?
Cycloid
Ctenoid
Ctenoid scales have spine-like structures near the “tip” of the cone, what are they for?
To help attach the scale to the fish
Describe Placoid scales
Hard
Look like a tooth
Planted in the dermis and projected out of the epidermis
What is the lateral line system?
Series of canals that are used to detect low-frequency vibrations in the water
What is the function of neuromasts in the lateral line system
Neuromasts consist of little sensory cells with a hairline structure that projects into the canal that senses vibrations through the displacement of hte cupula
T/F: The lateral line canal has direct contact with water outside the fish
True
Describe Class Mxini
Hagfish
Jawless
Vertebrae lacking
Notochord present in adults
No paired fins
No larval stage
Lots of slime secretion
Describe class Petromyzontida
Lampreys
Jawless, sucker-like mouth with rasping structures
No paired fins
Rudimentary vertebrae
Ammocoete larval form
Some predatory, some filter feeders
Describe class Ostracodermi
Jawless
Many with no paired fins
Heavily armoured head
Extinct
Describe class Placodermi
Early jawed fish
Armoured head/trunk
Paired fins
Extinct
Describe class Chondrichthyes
Sharks/rays
Jaws present
Paired fins
Cartilaginous exoskeleton
Placoid scales
Teeth in jaws
Describe class Sarcopterygii
Lobes at base of fins
Have lungs and modified circulatory system
Two of the three groups extinct
Describe class Actinopterygii
Modern day fishes
Body endoskeleton
Operculum
Swim bladder
Scales of various types
