Lecture 8 DA Flashcards
What are 6 characteristics of subphylum vertebra?
Hollow dorsal nerve cord, extends into the brain anteriorly.
Internal skeletal cranium protects brain.
Notochord terminates at the cranium’s base.
Head, trunk and post anal tail.
Well developed ventral heart.
Have pharyngeal slits.
What is a feature of advanced clades in subphylum vertebra?
Notochord is replaced by cartilaginous or bony vertebral column.
What does the notochord evolve into? What about paired fins and gills?
Notochord - vertebral column
Paired fins - limbs
Gills - lungs
What are fish?
Aquatic vertebra with gills.
What can be a fish?
Anything that isn’t a fish.
If appendages are present on fish, what are they usually?
Fins.
What is the skin of fish like?
Covered in scales.
What is the most diverse group of vertebrates?
Fish (jawed specifically).
What do fish dominate?
Fauna of aquatic environments.
What did tetrapods evolve from exactly?
Sarcopterygii - the rhipidistians.
What did all fish descend from?
Unknown free swimming protochordate.
What are agnatha?
Jawless fish.
What kind of body and skeleton do agnatha have?
Cylindrical body with cartilaginous skeleton.
What is the tail of agnatha like? Is it symmetrical?
Heterocercal tail, not symmetrical.
Do agnatha have paired fins? What about ventral fins? What are their fins in general like?
No paired fins, or ventral fins. Fins have a broad base.
What are the two classes of agnatha, and their common names?
Myxini - hagfish
Petromyzontida - lamprey
What is the water environment of myxini?
Entirely marine.
What do myxini feed on?
Dead or dying fish.
How are myxini adapted to feeding?
Attach to food using keratinised plates. Tear food using rapss. Ties a knot in its body for leverage.
Do myxini produce slime?
Yes.
Do myxini have larva?
No, large eggs, but no larva.
Do myxini have osmoregulation?
No.
What is the water environment of petromyzontida?
Marine or freshwater.
Where do all petromyzontida spawn?
Freshwater streams.
Do petromyzontida have a larval stage?
Yes, called ammocoete larva.
What is the difference between the parasitic and non parasitic petromyzontida?
Parasitic - attach to fish via suckers.
Non-parasitic - do not eat after becoming adults, spawn then die.
What are the most diverse groups of vertebra?
Jawed fish.
What are the two classes of jawed fish, and are they cartilaginous or bony?
Chondrichthyes - cartilaginous
Osteichthyes - bony
What are the subclasses of chondrichthyes and common names?
Elasmobranchii - sharks/skates
Holocephali - chimaera/ratfish
What are most chondrichthyes?
Most are marine predators.
Do chondrichthyes have paired fins? What are their scales like?
Yes. They have placoid scales.
Do chondrichthyes have an operculum?
No.
Where are the special sensory organs of chondrichthyes located?
Dorsal part of the head.
Do chondrichthyes have a lateral line system?
Yes.
How do rays/skates prevent clogged gills?
Have large spiracles to prevent clogging.
What are the spines and tails of rays/skates like?
Have saw toothed spines and whiplike tail.
Are there electric rays?
Yes, they can have electric organs on the side of their head.
What are the tails of sharks like?
Asymmetrical heterocercal tail.
What happens to the vertebral column of sharks towards the tail?
Turns upwards and extends into the dorsal lobes of the tail.
What are the teeth of sharks like?
They have a replaceable row of teeth.
What are the jaws and teeth of subclass holocephali (chimaera) like?
No teeth, jaws have flat plates.
What are the spines of subclass holocephali (chimaera) like?
Erectine dorsal spine, can be poisonous.
What are the two classes of osteichthyes?
Sarcopterygii
Actinopterygii
Do osteichthyes have an operculum?
Yes.
Do osteichthyes have a swim bladder? What is the purpose of a swim bladder?
Yes they do. It is used for buoyancy.
What is the swim bladder associated with?
The digestive system, sometimes for oxygen uptake in some species.
What are sarcopterygii?
Lobe finned fish - lungfish.
What are the fins of sarcopterygii like?
Strong, muscular lobe like fins.
What gave rise to tetrapods?
Sarcoptergyii.
What are the 2 subclasses of actinopterygii? Are the teleosts or non teleosts?
Chondrostei - cartilaginous, non-teleosts.
Neopterygii - bony, both teleost and non-teleost.
What is the most diverse class of fish?
Neopterygii.
What is the swim bladder an offshoot of in teleost ray finned fish?
GIT tract.
What is the area before a fish’s fin called?
Peduncle.
How do teleost ray finned fish swim? What are the shapes of their fins?
Sickle shaped fins. Swim by thrusting tail fin. More efficient.