osmoregulation in invertebrates.

osmoregulation in invertebrates- it is a processes by which any organisms maintains the fluid and salt balance of its body, which is important for proper functioning of organs .

1. ZOOLOGY PRESENTATION GDC COLLEGE REWA

2. OSMOREGULATION IN INVERTEBRATES

3. SYNOPSIS 1).INTRODUCTION. 2). DEFINITION. 3).CLASSIFICATION OF MEDIUM ON THE BASIS OF OSMOLARITY. 4).CLASSIFICATION OF ANIMALS ON THE BASIS OF THEIR ABILITY TO REGULATE OSMOTIC CONCENTRAT 5).OSMOREGULATION IN INVERTEBRATES. PROTOZOA. PORIFERA. COELENTERATA. PLATYHELMINTHES (FLATWORMS). NEMATODA (ROUNDWORMS). ANNELIDA. VII. ARTHOPODA. VIII. MOLLUSCA. IX. ECHINODERMATA. 6). CONCLUSION .

4. 1). INTRODUCTION- Most animals get water that is present in the food only, others drink it too, and is also formed during respiration. Water is essential for life, its loss called DEHYDRATION. However, the excess of water may dilute body fluid, and causes BLOOD PRESSURE and OEDEMA. Excess of water is a waste product and it is excreted in sweat, urine and feaces. Regulation of water and salt balance of the body is called OSMOREGULATION. Therefore,osmoregulation is an essential process to regulate the cellular metabolic activities.

5. 2). DEFINITION- It is a process that regulate the body’s salt and water content. It maintains the composition of body fluids at a steady state for efficient metabolism in the cells. Body fluids are of two types-1). Intracellular fluid. 2). Extracellular fluid. Intracellular fluid- fluid found within the cells. for example; cytoplasm. • Extracellular fluid - fluid found outside the cells for example; blood, lymph. • Osmoregulation involves water movement which follows solute by osmosis.

6. • OSMOSIS- It is a type of diffusion where the movement of water occurs from a dilute solution (hypotonic) to a strong solution (hypertonic) across a semi-permeable membrane. • OSMOLARITY - It is the total solute concentration expressed as moles of solute per liter of solution. Its unit of measurement is milli osmol per liter (mosmolLˉ¹). Osmolarity of fresh water is generally less then 50mosmolLˉ¹. 3) .CLASSIFICATION OF MEDIUM ON THE BASIS OF OSMOLARITY- There are three types of mediums- . ISOTONIC MEDIUM- A solution having concentration equal to that of the living cell is called isotonic medium. RBC’S placed in a isotonic medium neither swell up nor shrunk in shape. HYPOTONIC MEDIUM – A solution having LOW concentration than that of a living cell is called hypotonic medium.

7. • RBC’S placed in hypotonic medium gets swell up in shape . 3). HYPERTONIC MEDIUM- A solution having concentration higher then that of a living cell is called hypertonic medium. •RBC’S placed in a hypertonic medium gets shrunk in shape. figure showing RBC’S in different concentration mediums.

8. 4).CLASSIFICATION OF ANIMALS ON THE BASIS OF THEIR ABILITY TO REGULATE THEIR OSMOTIC CONCENTRATION- 1).OSMOREGULATION IN AQUATIC ANIMALS- There are four types of animals-1).Poikiloosmotic animals. 3). Osmoconformers 2).Homoiosmotic animals. 4). Osmoregulators. Poikiloosmotic animals- Animals in which internal osmotic concentration varies according to its external environment are called poikiloosmotic animals. for example; lower invertebrates, many annelids. It includes- Stenohaline Animals- Aq uatic animals which tolerate only a narrow range of salinities and are bound to constant salt content environment are called stenohaline. 2 ). Homoiosmotic Animals- Animals which maintain a constant osmotic concentration of body fluid in changing external salinity are called homoiosmotic animals. a). Euryhaline animals- Animals that can tolerate a wider range of osmotic concentration or tolerant to verities of salinities are euryhaline.ex- carcinus maenas , it can live in salt and brackish water .

9. OSMOCONFORMERS AND OSMORRGULATORS- 3 ). Osmoconformers - Animals in which the concentration of body fluid changes according to their external environment are osmotically labile(dependent), are belong to the category of osmoconformers. for example- all aquatic invertebrates. 4). Osmoregulators - Animals which are able to maintain their internal osmotic environment constant are osmotically stable(independent) are belong to the category of osmoregulators. For example- all vertebrates, except; myxine.

10. 6). OSMOREGULATION IN INVERTEBRATES- Osmoregulation in protozoan's- Osmoregulation in Amoeba- Osmoragulatory Organ- Contractile vacuole. Mechanism for osmoregulation- The protoplasm of amoeba proteus is of higher concentration then the freshwater of its environment. Due to the difference in concentration between the protoplasm and outer environment, water is actively secreted in to the contractile vacuoles by endo-osmosis through the vacuolar membrane. Tiny membrane bound water filled feeder vacuoles also get incorporated in to the contractile vacuole filling it with water. As water, continues to fill the vacuoles it increases in size.

11. When it becomes fully expanded, it comes and lie in the gelated ectoplasm zone where the ectoplasmic pressure results in contraction and bursting. • Due to the force of contraction, the content of vacuoles that is, water, CO2,ammonia Are discharged to the outside . Contractile vacuole • mechanism of osmoregulation Osmoregulation in paramoecium- Osmoregulatory Organ- Two contractile vacuoles.(anterior and posterior). Mechanism for osmoregulation- An excess of water accumulate in the body because of continuous endo-osmosis,the concentration of body cytoplasm being higher then the external medium .

12. Some extra amount of water is taken in during the ingestion of food. • This extra amount of water is got rid off by contractile vacuole. • The contractile vacuole contract(systole) and expand(diastole) at regular intervals Assisted by contractility of myofibrils . •Now the water from cytoplasm is secreted in to some of the tubules of endoplasmic reticulum. From endoplasmic reticulum it flows down the nephridial tubules in to the feeder canals to accumulate in latters ampulla. This ampulla converge and discharge in to contractile vacuole . O smoregulation in paramecium .

13. when vacuole has grown to maximum size it contract and discharged through an excretory pore. The marine and parasitic protozoan’s don’t face this problem as their environment is isotonic to their cell contents. Therefore, they lack contractile vacuoles. II). OSMOREGULATION IN PORIFERA- The main excretory mater is ammonia. It leaves the cell by diffusion in to the water filling the canals and surrounding the sponge. From canal the waste matter is carried out by outgoing water current. Most sponges are marine, with no problem of surplus water in their cells. Few sponges live in hypotonic fresh water , for ex- spongilla , have contractile vacuole in most of their cells. This contractile vacuole functions in osmoregulation for individual cells. Water movement in sycon

14. III). OSMOREGULATION IN COELENTERATA- They also get rid off waste matter by simple diffusion through the cells. The waste matter entering the coelenteron leaves when its water is renewed. Most of the coelenterons too are marine. Marine ones, don't have osmoregulatory Problems. A few inhabit hypotonic fresh water. How fresh water coelenterates regulate The water content of cells is not clear, as There are no contractile vacuoles found In them. Water movement in hydra .

15. IV. Osmoregulation in platyhelminthes(flatworms)- Osmoregulatory organ- Flame cells. Like the contractile vacuole ,The chief role of flame cells is to perform osmoregulation. Mechanism of osmoregulation- They have flame cells with the bundles of vibratile cilia for excretion. For example-planaria, flukes and tapeworm. Flame cells receive the solutes and water from the surrounding tissue fluid by ultrafiltration. Then they discharged the solutes and water into the nephridial ducts. In the nephridial ducts the useful materials are reabsorbed from it and some waste substances are secreted in to it.

16. • The urine which is formed finally, is eliminated to the exterior by excretory pore. • In aquatic worms, the excretory product is ammonia . But, in parasitic worms, the excretory product is fatty acid. The fresh water flatworms have more flame cells then the marine ones. On the left hand side, there is a diagram- Showing the structure of a flame cell in fasciola hepatica, teania solium etc .

17. V. OSMOREGULATION IN NEMATODA(Roundworms )- 1). Osmoregulation in Ascaris- • Osmoregulatory organ- They have a system of intracellular canals and Cannaliculi opening out at the exterior pore. It has a H-shaped excretory system formed of two intracellular longitudnal excretory Canals interconnected by a transverse netwo -rk of canaliculi. This system plays a great role in water regula- - tion, then in excretion. Nitrogenous waste (ammonium ions) are Mainly lost by diffusion across the body- Wall.

18. VI. OSMOREGULATION IN ANNELIDA- OSMOREGULATORY ORGAN- They have many coiled tubular stuctures called metanephridia for osmoregulation and excretion. STRUCTURE OF METANEPHRIDIA- It typically consist of cilliated nephridial canal. This canal opens in to coelom by nephrostome. This canal opens outside or In to he gut by nephridiopore. MECHANISM OF OSMOREGULATION- Nephridia have rich blood supply,solute extract and water from blood by ultrafiltraton. The nephridia then discharge this filtrate in to the nephridial canal. In nephridial canal the useful material are reabsorbed from it, and some waste substances are secreted in to it. The final urine so formed is passed in to the gut or to the exterior by nephridiopore. Fluid expelled at the body surface consist of water, ammonia in the aquatic from and urea in land form and salt which have not been reabsorbed.

19. • Excretion through the gut is adaption for water conservation. • in the gut, water is absorbed in the blood. • This metanephridia bring about excretion and water and ion regulation in body . Types of nephridia in different classes of annelida- Class 1- polychaeta(nereis)- Type of nephridia- All nephridia opens out by a nephridiopore and thus are ectonephric. Class 2-oligochaeta(earthworm)- Types of nephridium- In earthworm, nephridia are micronephric. In earthworm, depending upon their position the Nephridia are of three types- Septal nephridia. Integumentary nephridia. Pharyngeal nephridia .

20. 1 ). Septal nephridia- These nephridia are attached on septa. • These are enteronephric as these open into the gut . 2). Integumentary Nephridium - These nephridia are attached on the inner side of integument(skin). Like septal nephridia these are also enteronephric. 3) . Pharyngeal Nephridia- These are present in three pairs of groups of nephridia. Location- one pair in each of 4 th ,5 th and 6 th body segment. unlike septal and integumentary nephridia, these are ectonephric. • Annelid nephridia bring about excretion as well as water and ion regulation. In earth worms, excretory fluid keep the skin moist for cutaneous respiration .

21. 3). Class-Hirudinaria(leech))- Osmoregulatory organ- 17 pairs of small coiled tubes,nephridia. Location- one pair in each segment from 6 th to 22 nd . Types of nephridia- there are two types of nephridia. 1). Testicular Nephridia. 2). Pre-testicular Nephridia . 1). Testicular nephridia- Location- posterior 11 pairs of nephridia,lying one pair in each segment from 12 th to 22 nd are termed as testicular nephridia. Due to the presence of a pair of testis sacs in each of these segments, these nephridia are named as testicular nephridia. A typical nephridium is a horse shoe-shaped structure traversed by a complicated system of canals.

22. It consist of 6 parts- 1. Main lobe. 2. Vesicles and vesicle duct. 3. Apical lobe. 4. Inner lobe. 5. Initial lobe, and 6. Ciliated organ. 2. Pre- testicular Nephridia- Location- 1 st 6 pairs of nephridia are termed as pre-testicular. since, these are located in segments 6 th to 11, without testis sacs themselves but in front of those containing testis sacs, therefore they are termed as pre-testicular lobe. they resemble to the testicular nephridia in all respects, except that their initial lobe end loosely in general connective tissue on their side of ventral nerve cord. There are no testis sacs,pre-nephrostomial ampulla and cilliated organ in their segments.

23. VII. OSMOREGULATION IN ARTHOPODA- • Types of osmoregulatory organs in different classes of arthopoda- 1). Class 1-Insecta(cockroach)- Osmoregulatory organ - Malphigian tubules. Location- float freely in the haemocoel . In cockroach,very fine,un branched,yellowish, Blind malphigian tubules are present. These tubules open in to the alimentary canal at The junction of midgut and hindgut. Each tubule is lined by cuboidal epithelium of Glandular cells. Malphigian tubules are capable of peristalsis to Move the waste matter though them. Structure and function of malphigian tubules- it has two regions, distal and proximal parts.

24. its distal part secretes inorganic ions, uric acid, by active transportation and Water by the diffusion from haemolymph. This region is alkaline, from here, extracted matter moves in solution called Primary urine, towards ileum. Now, in its proximal part,CO2 passes from haemolymph into its lumen. This makes the content acidic, and this in turn makes the uric acid to precipitate. Water, ions and useful materials are reabsorbed, changing the primary urine Into final urine. By the gentle tubule contractions,the precipitate is carried out into the gut. More reabsorption takes place in the hind gut. almost solid uric acid is finally eliminated with feaces. Excretion through the gut is an adaptation to conserve water. It is necessary as cockroach does not drink water. The ability of malphigian tubule to control the salt and ion concrntration is not much. Terrestrial insects excrete uric acid, the aquatic ones excrete ammonia.

25. 2). Class-Crustacea(Prawn )- Osmoregulatory organ- They have a pair of antennary or green glands and a median renal sac for osmoregulation and excretion. Location- lie at the base of antenna and opens out. It is formed of an end sac, a labyrinth and a bladder. These draw the water having dissolved substances from the haemolymph in to their end sac by ultrafiltration. Most salts are absorbed while remaining flows into bladder. Excretory fluid comes here via lateral ducts from the renal sac that lies over stomach. Waste fluid is passed via renal aperture.

26. 3). Class-Arachnida(scorpion and Spider)- Osmoregulatory Organ- They have malphigian tubule or coxal glands,or both for excretion. Spiders excrete guanine and are said to be guanotelic. VII. Osmoregulation in Mollusca(unio )- Osmoregulatory organ- One or two pair of kidney for excretion and osmoregulation. Mechanism of osmoregulation- The kidneys open in to the pericardium(coelom) at one end by renopericardial aperture(nephrostome). At the other end it opens into the mantle cavity by nephridiopore. The auricular wall form pericardial fluid by ultrafiltration across it.

27. In kidney, the primary urine is modified to final urine by selective reabsorption and secretion. Final urine is passed into the mantle cavity via the nepridiopore. In aquatic form waste matter is ammonia. In land form it is uric acid. VIII . OSMOREGULATION IN ECHINODERMATA(STAR FISH)- Osmoregulatory organ- They lack special excretory and osmoregulatory organs. The nitrogenous waste materials,cheifly ammonia are lost by diffusion through the thin walls of gills(dermal branches) and tube feet(podia). 7). CONCLUSION- From the above description, it is clear that there is a very crucial relationship of water and salt concentration between an organism and its external environment, by which it maintains the homeostasis of the body and regulate all the cellular metabolic activities.

28. THANKYOU SUBMITTED BY- ANKITA RICHHARIYA . MSC 1 ST SEM . (ZOOLOGY ).