Strategies of Buoyancy in Teleosts Flashcards
1
Q
What are the 3 strategies teleosts use to achieve buoyancy?
A
- retention of low density compounds
- reduced skeletal-muscular system
- swimbladder
2
Q
What fish have retention of low density compounds rarely seen in? Why?
A
- freshwater (not deep and oligotrophic)
3
Q
Why is retention to low density compounds only in some marine fish?
A
- deeper/benthic (on bottom)
4
Q
Deeper fish = ___ pressure on gas bladder. what do they rely on?
A
-more
- low density compounds
5
Q
What fish have reduced skeletal-muscular system? Why?
A
- deep sea (<1000m)
- oligotrophic + gas bladder inflation under high pressure (expensive)
6
Q
Having no gas bladders is a ____ condition in teleosts
A
- derived (SG = 1.1)
7
Q
What comes along with reduced skeletal-muscular system in teleosts?
A
- enlarged, dilute, fluid filled cranial cavities (50% osmolarity of body fluids)
- density less than SW
8
Q
Do fish use gas bladder to swim?
A
- no
9
Q
What is the composition of gas bladders?
A
- 79% N2
- 21% O2
10
Q
What did the gas bladder arise from?
A
- ancestral lung (gas exchange) in early jawed vertebrates
11
Q
What do fish use gas bladders for?
A
- to achieve neutral buoyancy
12
Q
What fish achieve neutral buoyancy? why?
A
- pelagic fish in water column
- energetically efficient
