Lab 8 - Early Chordates & Fishes Flashcards
What are the two subphylum of early chordates?
Urochordata and Cephalochordata
What are the two superclasses of fish?
Agnatha and gnathostomata
What subphylum are fish in?
Vertebrata
What are the fish classes that are extinct?
Ostracoderms and placoderms
What are the classes of agnatha?
Myxini and petromyzontida
What are the classes of gnathostomata?
Chondrichthyes, actinopterygii, and sacropterygii
What are the characteristics of the superclass agnatha?
Jawless fish
Do gnathostomata have jaws or nah?
Yes
What kind of fish are chondrichthyes and give examples.
Cartilaginous fishes (sharks, skates, rays)
What kind of fish are actinopterygii and give some examples.
Bony fishes (most other fishes, not sharks/skates/rays)
What kind of fish are sacropterygii and give some examples.
Lobe-finned fishes (sister to all tetrapods)
What are fish?
A polyphyletic group of mostly aquatic organism
Fish evolution - what supporting structures did fish evolve?
Paired appendages
What level of organization do fish have?
organ-system level
How many germ layers do fish have?
3 - triploblastic
Are fish deuterostomes or protostomes?
deuterostomes
What kind of symmetry do fish have?
bilateral
What kind of body cavity do fish have?
Coelom
What kind of support system do fish have?
living endoskeleton - skeleton grows with them
What are shark and ray skeletons made of?
cartilage
What type of fish have a bony skeleton?
Ray-finned fish
What upgrade do fish have for respiration?
Counter-current gas exchange
How do fish reproduce?
Sexually, although some reproduce asexually
What are the three reproductive strategies?
Oviparity, ovoviviparity, and viviparity
What is oviparity?
The eggs are laid
What is ovoviviparity?
internal fertilization , embryo receives nutrients from egg, born live
What is viviparity?
internal fertilization, embryo receives nutrients directly from the mother, born live
What kind of egg do fish produce?
Anamniotic egg
What is an anamniotic egg?
Laid in water, permeable, gas exchange
What kind of sensory structures do fish have?
Central nervous system, otoliths, lateral lines, eyes, olfactory system (nares)
What do otoliths do for fish?
For hearing
What do lateral lines do for fish?
Detect vibrations in the water
What kind of digestion do fish have?
Complete
What help fish with locomotion?
Paired fins, specialized organs for buoyancy fins, specialized organs for buoyancy
What do fish use paired fins for?
Stability and movement
What do fish use swim bladders for?
Buoyancy
How do sharks regulate buoyancy?
with their livers
What do fish excrete?
ammonia (needs to be diluted with lots of water - highly toxic but doesn’t require a lot to energy to produce)
What organisms are found in the subphylum cephalochordata?
Lancelets
How do cephalochordata respire?
Gills
What is apart of a cephalochordata’s nervous system?
dorsal, hollow nerve cord
What kind of support does a cephalochordata have?
endoskeleton
What kind of support does a cephalochordata have?
endoskeleton
How do cephalochordata reproduce?
external fertilization - dioecious
How do cephalochordata get food?
Filter feeding
What kind of heart does a cephalochordata have?
Ventral heart
Do cephalochordata have all five chordata characteristics?
yes
What kind of organisms are found in subphylum urochordata?
Tunicates
Are urochordata motile or sessile?
sessile
What is apart of a urochordata’s nervous system?
dorsal, hollow nerve cord
What kind of support does a urochordata have?
nonliving ‘skeleton’ that contains cellulose
How do urochordata reproduce?
internal and external fertilization, dioecious
How do urochordata digest?
filter feeding
What kind of circulation do urochordata have?
open
How do urochordata respire?
gills
Do urochordata have all five chordate characteristics?
larva do, adults lack a tail, dorsal hollow nerve cord, and notochord
What are the five characteristics of chordates?
Dorsal, hollow nerve cord; post-anal tail; notochord; pharyngeal gill slits; endostyle
What are some structures unique to fish that allow them to live in aquatic environments/
gills w/ counter-current exchange; swim bladders; protrusible jaws; a fine-tuned excretory system
How does counter-current exchange work?
blood flow goes against the H2O flow
