Are vertebrates protostomes or deuterotomes? What is one of the characteristics?
Dueterostomes
All have pharyngeal slits
Characteristics of chordates
1) Dorsal hollow nerve cord
2) Notochord (rigidity- rapid locomotion)
3) Muscular post-anal tail (present in humans during embryo development)
What are pharyngeal slits?
"Gill slits" - Located on surface of head - Ancestral trait in dueterostomes NOT IN ECHINODERMS - supported by arches
What is the function of pharyngeal slits?
How many gill slits do bony fishes have? What are they covered by?
Bony fishes have 4 pairs of gill slits
Covered by operculum
Gil filament structure and blood flow mechanisms
What is advantage of countercurrent exchange?
The flowing of blood and water in opposite directions ensures partial pressure gradients are maintained. It achieves maximum gas exchange.
Circulatory system of fish
4 characteristics of vertebrates (ie, skeleton, systems)
4 characteristics of vertebrates (ie, skeleton, systems)
What distinguishes chordates and vertebrates?
All vertebrates have a vertebral column while some chordates only have notochord
What is name for jawless fish? Fish with jaws?
Jawless fish are Agnathans
Fish with jaws are Gnathostomes
Two types of agnathans + characteristics
- Hagfish: Knot- tying, mucous production, osmotic concentration, used for leather
What type of skeleton do agnathans have? What are their other main characteristics?
cartilaginous skeleton
What are jaws?
Formed by fusion of gill arches
What are paired fins?
- enable active swimming
What is name for cartilaginous gnathostome fish and their characteristics?
Chondrichthyes (sharks, rays…)
What is name for bony fishes?
Osteichthyes
What are the two types of Osteichthyes?
- Lobe-finned (lungfish, Coelocanth) 2 ventral pockets formed off esophagus (SUPPLEMENTAL)
How did fish get stronger, and faster?
What is a coelocanth?
“living fossil”
Really old fish (chordate) thought to be extinct until recently
What are lung fish- how do they demonstrate the transition to land?
Lungfish are a type of fish- they would live in mud during droughts
Have two pouches that can be used “as lungs” when needed
What were the 4 advantages of moving to land?
What are the advantage of terrestrial respiration?
- Gases diffuse faster in air