salinity Flashcards
Osmoregulation
Maintain fluid and electrolyte levels by regulation of osmotic P of fluids
Excretion
Getting rid of metabolic wastes
Osmoconformers regulation
Isosmotic with seawater
Body volume changes.
Burrow to avoid fast and large changes in temperature and salinity.
May regulate ionic comp of body fluids
conformers Intracellular regulation
Cells isosmotic to body
Organic molecules in cells maintain body fluid
Organic molecules used as regulators
AA glycine regulated by protein degradation and synthesis. Concentration increases with salinity stress.
Isosmotic conformers
High conc urea in coelacanth. Urea build up prevents toxic salt concentrations.
Elasmobranch’s remove salt by secretion.
hypo osmotic conformers
Teleosts 1/4 to 1/3 sea water concentration.
Lose water so must drink.
Excess NaCl out gills, Cl- actively transported out and Na+ follows.
small vol of isotonic urine, kidneys excrete divalent ions.
Intestines remove ions and water.
At sea drink excrete salt out gills and produce little urine, in fresh water it is opposite.
Marine vertebrates salt regulation
Hyperosmotic urine, remove excess salt from food and seawater/
Invertebrate exretion
Low level invertebrates, diffusion to remove N
Higher, tubular filtration, selective reabsorption, secretion and excretion
Crustacea excretion
Antennal gland, bulb like sac. Coelomsac joins labyrinth, narrow canal joins to bladder.
Structures, osmotically active. Urine 1st form in coelomsac through bladder at base of 2nd antenna
Rotifer Excretory systems
Protonephridia in rotifers. Tubule system through body.
Cilia draw fluid in, excess fluid out skin.
Solutes reabsorbed and dilute urine.
Mollusc and annelid excretion
Simple tubular system.
Internal openings collect coelomic fluid. When cilia present on opening beat.
Metanaphridia, excretory and osmoregulation function.
Excrete water, salts, ions and N by urea
