2. RESPIRATION n STRUCTURES; arch, filaments, rakers n WATER FLOW- in mouth & out operculum (gill cover) n COUNTER CURRENT SYSTEM FOR EFFICIENT OXYGEN UPTAKE

4. COUNTER CURRENT SYSTEM n Blood flows counter (opposite) n to the flow of water n Result= more Oxygen transferred to the blood

5. RESPIRATION/ GILLS (contd.) n GILLS with special glands to excrete n excess salt (salt water sp.) n VARIATIONS; n LUNGFISH= can gulp air into its gas bladder n Gill rakers used to filter plankton (anchovy and herring).

6. SWIM or GAS BLADDER n ;for NEUTRAL BOUYANCY n (neither floats or sinks) n Absent in bottom fish (Halibut) –and Pelagic fish (Tunas)

8. n In a fish at 7000 meters depth, the pressure need in the bladder would be 5 tons per square inch, or 700 atmoshperes. n What happens to a rockfish when caught and rapidly reeled to the surface?