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Osmoregulation. The problem of osmolarity:. salt water 35 ppt. fresh water 0-5 ppt. The problem of osmolarity:. Hyper-osmotic. salt water 35 ppt. fresh water 0-5 ppt. FISHES. Hypo-osmotic. The problem of osmolarity:. Hyper-osmotic. salt water 35 ppt. fresh water 0-5 ppt. FISHES.
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The problem of osmolarity: salt water 35 ppt fresh water 0-5 ppt
The problem of osmolarity: Hyper-osmotic salt water 35 ppt fresh water 0-5 ppt FISHES Hypo-osmotic
The problem of osmolarity: Hyper-osmotic salt water 35 ppt fresh water 0-5 ppt FISHES Hypo-osmotic fishes are either: stenohaline - tolerant of limited range of osmolarity euryhaline - tolerant of wide range (where is this useful?)
How fish deal with being osmotic misfits 1. osmo-conformers (hagfishes) maintain isosmotic conditions
How fish deal with being osmotic misfits 1. osmo-conformers (hagfishes) maintain isosmotic conditions 2. salt supplementers (marine elasmobranches and coelacanths) high urea content and TMAO (trimethylamine oxide) low permeability to Na+, Cl- excrete excess Na+, Cl-
How fish deal with being osmotic misfits 1. osmo-conformers (hagfishes) 2. salt supplementers (marine elasmobranches and coelacanths) 3. hyposmotics (marine teleosts) tend to lose water, replace by drinking gill cells pump in water, not salts
How fish deal with being osmotic misfits 1. osmo-conformers (hagfishes) 2. salt supplementers (marine elasmobranches and coelacanths) 3. hyposmotics (marine teleosts) 4. hyperosmotics (freshwater fishes) excrete large volumes of water gill chloride cells pump in salts often euryhaline (striped bass, tilapia, drum)
fresh water salt water Diadromous fishes anadromous - Pacific salmon, lamprey, shad
fresh water salt water Diadromous fishes anadromous - Pacific salmon, lamprey, shad behavioral change (drinking) changes in kidney function metamorphosis – cued to photoperiod, lunar cycle
fresh water fresh water Diadromous fishes anadromous - Pacific salmon, lamprey, shad landlocked species (potamodromous) - reversion of salt-water tolerance
Diadromous fishes anadromous - Pacific salmon, lamprey, shad landlocked species (potamodromous) - reversion of salt-water tolerance catadromous - eels fresh water salt water Credit: ICES