bony fish Flashcards
what classes belong to the superclass agnatha (jawless fish)
1) cephalaspidomorphi = lamprey
2) myxini = hagfish
what classes belong to the superclass ostichthyes
1) sarcoptergii - lobe- finned fish
2) actinoptergii - ray-finned fish
how do most telosts feed
suction feeding
outline the evolution of the jaw
the premaxilla at the front of the jaw moved down as well as the maxilla allowing forward movement of the jaw without moving the body, decreasing pressure so water is taken in
what organ allows for neutral buoyancy in fish
1) swim bladders
- means lower cost of transportation opening up new niches
what are some advantages of using gas as a buoyancy aid
- 800 times less dense than lipid; much less is required for neutral buoyancy
- the quantity of gas can be adjusted quickly so able to compensate for short term changes
what are the two types of swim bladders
1) physotomatous fish = penumatic duct between swim bladder and gut open throughout life
2) physoclistous fish = pneumatic duct closes early in development so digestive tract not connected
what is the ideal shape from continuous swimming
fusifrom (spiral shaped)
what happens to the swim bladder on decent vs ascent
D = swim bladder compresses so fish becomes negatively buoyant so need more gas in the bladder to remain neutrality
A= swim bladder expands so becomes positively buoyant so needs to expel gas from gas bladder
what are some adaptations for buoyancy in deep-sea fish
lightly ossified skeleton
few, if any scales
reduced musculature (important if weak bones)
loss of swim bladder entirely
outline teleost reproduction
- most are broad cast spawners
- unquie to aquatic animals
- high fecundity of small eggs
define attrition
far more zygotes produced than will ever reach maturity- mortality rates over 99.99%
how do fish filter feed
often with large, toothless mouths with long gill rakers which select food by particle size
what are the three classes of fish most used in aquaculture
1) clupeiformes
2) scombridae
3) gadiformes
