Osmoregulation in Fishes and Birds

Osmoregulation is the process of maintaining salt and water balance (osmotic balance) across membranes within the body. The fluids inside and surrounding cells are composed of water, electrolytes, and nonelectrolytes. An electrolyte is a compound that dissociates into ions when dissolved in water.

1. OSMOIONIC REGULATION IN FISHES AND BIRDS REXLIN THERES S 20-PZO-006

2. SYNOPSIS INTRODUCTION IMPORTANT TERMS-OSMOSIS, ISOTONIC,HYPOTONIC AND HYPERTONIC OSMOREGULATION IN FISHES OSMOREGULATION IN FRESH WATER FISHES OSMOREGULATION IN MARINE WATER FISHES OSMOREGULATION IN MIGRATORY FISHES OSMOREGULATION IN BIRDS OSMOREGULATION IN MARINE BIRDS OSMOREGULATION IN TERRESTRIAL BIRDS CONCLUSION VIDEO REFERENCE QUESTION BANK

3. The maintenance of an optimal concentration of water and salts in the tissue and body fluids of animals is called osmoregulation. The term was first coined by Hober (1902). INTRODUCTION

4. OSMOSIS Osmosis is the movement water molecules through a selectively permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of higher solute concentration),

5. ISOTONIC,HYPOTONIC AND HYPERTONIC Hypotonic animal –has a lower concentration salt than external environment Isotonic animal –has a similar concentration salt to the environment Hypertonic animal –has a higher concentration of salt compare to external environment

6. TYPES OF OSMOREGULATION Osmoconformers Osmoregulators . Osmoconformers are organisms that keep their internal fluids isotonic to their environment, that is, they maintain an internal salinity similar to their external environment Osmoregulators regulate the salt concentration by spending a high amount of energy . Organisms that maintain an internal osmolarity different from the medium in which they are immersed have been termed osmoregulators .

7. OSMOREGULATION IN FISHES In all fishes kidney is the main osmoregulatory organ. Gill membrane also helps in osmoregulation. OSMOREGULATION IN FRESH WATER FISHES These fishes are Hypertonic to the environment i.e. the salt concentration of body fluid is higher than environment PROBLEMS Water continuously diffuses into fish body fluid through skin and gill membrane(Endo osmosis) Ions (Na+&Cl-) diffuses out through skin and gill membranes

8. PHYSIOLOGICL ADAPTATION IN FRESHWATER FISHES Kidneys are adapted to excrete large amount of dilute urine –have large glomeruli These fishes do not drink water Active uptake of salts with the help of chloride secreting cells present in gill lamellae EXAMPLE: Fresh water Teleost

9. OSMOREGULATION IN MARINE WATER FISHES These fishes are Hypotonic to the environment i.e. their body fluid have less salt concentration in comparison to surrounding water PROBLEMS Water continuously diffuses out of fish body fluid through skin and gill membrane(Exo osmosis) Salt diffuses from surrounding sea water into fish body through skin and gill membrane

10. ADAPTATION INVOLVED IN MARINE BONYFISHES – EXAMPLE: Teleost Production of less quantity of concentrated urine because kidney has small or no glomeruli Drink large quantity of sea water(salt) Excretion of excess of salts with the help of chloride secreting cells present in gill lamellae ADAPTATION IN MARINE CARTILAGINOUS FISHES- EXAMPLE: Sharks and Rays These fishes have same amount of salt in their body fluid as marine bony fishes . But these fishes have the ability to accumulate large amount of urea .Their tissue are adapted to function at high concentration of urea. High concentration of urea makes the body fluids isotonic to seawater. Excess salt is excreted by rectal salt gland

11. SUMMARY

12. OSMOREGULATION IN MIGRATORY FISHES Catadromous fishes migrate from freshwater to seawater for spawning Example : eel(Anguilla bengalensis) Anadromous fishes migrate from seawater to freshwater for spawning Example: Salmon Such fishes have to regulate their blood tonicity in the two contrasting media. Therefore it maintains itself by Drinking water or not drinking water chloride secreting cells of the gills function both as secreting and absorbing unit

13. OSMOREGULATION IN MARINE BIRDS Marine birds exhibit high rate of evaporation as they are not fully submerged in water Many drink sea water to compensate the water loss Birds that can adapt to a marine habitat, the need to excrete sodium chloride and generate free water far exceeds the capabilities of their kidneys. This requirement is met by secretion of a highly concentrated sodium chloride solution by paired supraorbital nasal salt glands connect with the nasal cavity

14. In birds that are fed a diet high in salt concentration, the glands increase in size and become even larger than normal. The salt gland generally remains inactive and starts secreting only in response to an osmotic stress The secreted fluid has a simple composition; it contains mostly sodium and chloride in rather concentration. EXAMPLES: Sea gulls, Cormorants, and Pelicans Location of salt gland in marine birds.

15. Skull of seabird has a pair of salt glands located over the eyes that excrete salty fluid from the nostrils which runs down grooves in the bill.

16. OSMOREGULATION IN TERRESTRIAL BIRDS The terrestrial habitat lacks both water and salts in the surrounding medium ,therefore, the terrestrial animals often face the problem of both water and salt losses. Water loss may be due to evaporation of water from the general body surface Salt loss may be due to excretion of concentrated urine

17. PHYSIOLOGICAL ADAPTATION IN TERRESTRIAL BIRDS For water conservation the body is covered by means of a water proof covering (FEATHERS) which prevents the evaporation of water from the body. Birds excrete a semisolid urine containing uric acid , thus minimizing water loss. Uric acid is quite insoluble in water, and it can be excreted without, the use of much water. Within the cloaca most of the water is reabsorbed and the waste is excreted in semisolid form.

18. HORMONAL CONTROL OF OSMOREGULATION VASSOPRESSINS -In birds , the hormone increases the permeability of the renal tubules to water and thus permits more water reabsorption and reduced urine production. PROLACTIN -In bony fishes prolactin from anterior pituitary enhances production of a dilute urine.

19. CONCLUSION Osmoregulation is an important process in animals as it allows organisms to maintain a balance between water and minerals at the cellular level despite changes in the external environment. Damage to the kidney through bacterial infection or other means is often deadly as these organs play an important role in mechanism of osmoregulation.

20. OSMOREGULATION IN FISHES

21. REFERENCES 1.http://epgp.inflibnet.ac.in/OsmoregulationinmarineairbreathinganimalsQuad1.pdf 2.https://www.shareyouressays.com/knowledge/short-notes-on-the-osmoregulation-in-terrestrial-animals/115194 3.https://www.petmd.com/fish/care/Osmoregulationdiffusion . 4.https://www.frontiersin.org/articles/10.3389/fphys.2010.00013/full BOOKS 1.Dr.P.S.Verma, B.S.Tyagi , V.K.Agarwal . Animal physiology 2.H.R.Singh,Neeraj Kumar. Animal physiology and biochemistry

22. QUESTIONS PART-A 1.Define osmosis 2.Differentiate Hypotonic, Hypertonic, and Isotonic 3.What is osmoregulation 4.What are the organs involved in osmoregulation in fishes and birds 5.Write down the problems faced by fresh water fishes 6. Explain the physiological adaptation in fresh water fish 7. Write down the problems faced by marine water fishes 8. Explain the physiological adaptation in marine water fish 9.Give examples of fresh water fish and marine water fish

23. 10. What are Catadromous fish? Give example 11. What are Anadromous fish? Give example 12.What is the function of supraorbital nasal salt glands 13. Write down the problems faced by terrestrial birds 14. Explain the physiological adaptation in terrestrial birds 15.Why osmoregulation is an important mechanism 16.What are osmoconformer 17.What are osmoregulatory 18.Name the hormone plays an important role in osmoregulation in fishes and birds

24. PART-B 1.Explain the mechanism of osmoregulation in fishes 2. Explain the mechanism of osmoregulation in birds PART-C 1.What is osmoregulation? Describe the physiological adaptation involved in osmoregulation in fishes and birds.