Marine Osmohomeostasis - Research Paper Example

Marine OsmoHomeostasis. Names Institution Affiliation. Abstract. Osmoregulation in marine life is paramount due to the hypertonic nature of the marine environment. The marine life possesses physiological advancements that enable them to maintain water and ionic balance in their bodies so that the can repulse the water loss to the environment. These adaptations are physiological, most of which are kidney and urine concentrations ability, water sources, feeding behaviors, renal responses, and hormonal regulations. The kidneys of marine animals re reniculate in structure that has more concentrating ability than terrestrial kidneys. Some marine life such as the pinniped and crustaceans can concentrate their urine above the seawater. These enable them to drink seawater without losing fresh water to the ocean. Water is mostly maintained by metabolic and dietary water, where ingestion helps to maintain the electrolyte homeostasis. The hormonal role of vasopressin is antidiuretic and remains inconclusive in marine life. Water and ionic balance are paramount and challenging especially to freshwater migratory species that visit saline environment for breeding. Homeostasis is a life-saving biological process in the marine environment failure to which the animals will lose ions and water to the environment disabling intracellular metabolism. Introduction. Water and ionic balance in the marine environment have been researched for decades to understand how marine animals survive and adapt marine life. Marine mammals are well adapted to these hyperosmotic environments (Holland, 1975). To achieve these physiological requirements, the physiological mechanisms intend to preserve water and avoid dehydration due to the osmotic potential created by the concentration differences. Water conservation in marine life is focused on water preservation while freshwater inhabitants, focuses on the conservation of electrolytes to maintain a hypertonic internal environment relative to the freshwater environment. Some marine animals have also adapted to prolonged fasting and sometimes undergo diapause in arid terrestrial environment. Water and ionic balance during diapause require more complex and robust ways of maintaining internal homeostasis. Occupying either extremely saline or adapting both saline and fresh water environment, and prolonged periods of fasting shows the dynamic scope of the osmoregulatory capacity of marine life mammals. Most marine animals are osmoconformers that are isotonic relative to seawater. This balance is a dynamic equilibrium with the environment marine environment. Osmoregulators gains electrolytes from the seawater due to higher diffusion gradient from high concentrates to lowly concentrated bodily fluids. These excessive sodium and chloride ions are transported back to the seawater against the concentration gradient. This process uses metabolic energy and linked proteins and the membrane that allows selective passage of unwanted anions and cations. Kidneys filter out the excess Ca2+, Mg2+ and SO42-. The marine osmoconformers regulate their solutes concentrations in their bid to homeostasis. Some organisms have specialized cells in the gills that actively accumulate chlorides and remove them successful from the body system (Madigan, Martinko, Parker, & Brock, 1997). Literature review. How do marine animals tackle high osmotic pressure in the marine environment? Extensive research has been conducted out to investigate the osmoregulatory mechanisms in the marine environment. Marine animals have specialized kidneys that allow them to inhabit areas of fluctuating concentrations. Members of order Cetaceans (dolphins and whales) have reniculate kidney, that is composed of lobes with discrete cortical tissues and single pyramid made of a single medullary pyramid as a single calyx (Bester, 1975; Vardy and Bryden, 1981). The kidneys of most marine animals support diving behavior. They have glycogen stores in proximal convoluted tubules. Have high vasa recta bundles and an elastic fiber that separates cortex and medulla (Pfeiffer, 1997). The kidneys of mammalian marine animals have anatomical advancements that enable them to concentrate urine than freshwater and terrestrial animals (Bester, 1975).There is a close correlation between the between medullary thickness and maximum osmolality (Vardy and Bryden, 1981). Cartilaginous fish such as rays and skates have plasma that s isosmotic to seawater. This high osmotic concentration relative to other vertebrates is achieved by higher levels of urea and trimethylamine oxide in the body fluids (TMAO). The TMAO stabilizes the proteins against the effects of urea. The blood of marine teleost’s are hypotonic to seawater, to replace the lost water; they drink seawater and actively secrete the electrolytes back to the system. Elasmobranchs and marine birds have a salt gland that secretes NaCl from their bodies. These animals are hypotonic, and this concentration gradient promotes ionic transfer to the body. The sharks have a rectal salt gland which actively secretes this excess salts. Marine birds have salt glands in their skulls while the fish have gills that filter excess salts from their bodies (Strogatz, 2001). Marine animals have ability to excrete highly concentrated urine with high osmotic potential than that of seawater (Bester, 1975; Costa, 1982; Maluf, 1989). This feature is also possible to fresh water inhabitants and is an indication that marine animals can retain this ability in fresh water. This increase in associated with increased plasma osmolality due to intake of ions. Marine animals do not concentrate urine levels of sodium and chloride to levels above seawater, and this is a clear indication that marine animals do not need to drink seawater to maintain their internal osmolality. Seals and sea lions have advanced ways of osmoregulation in their marine habitat. Seals can maintain their water balance by dietary water and metabolic water (Irving et al., 1935; Smith, 1936; Fetcher, 1939). Direct intake of seawater is of less importance and probably incidental during feeding. In some species such as Otariids, the water intake depends on ambient temperature as a means to counter thermal stress.In harp seals; ice consumption is common and drinks fresh water greedily when available. Drinking may not be significant, but incidental intake may contribute to electrolyte homeostasis. Diapause is a natural part of pinnipeds, but the time length varies among spices. The low turnover allows them to maintain water balance during a prolonged period of fasting. The oxidation and fats produce more metabolic water than any other form of oxidation (Ortiz et al., 1978; Castellini et al., 1987). Water needs to be preserved at higher levels during this fasting period to maintain water body contact. These are characterized by reduced protein catabolism and increases in urine osmolality, which collectively reduces water loss to the environment (Adams and Costa, 1993). Reduced glomerular filtration associated with high tubular resorption of water increases water conservation. Hormonal regulation of osmoregulation us mainly conveyed by angiotensin, atrial natriuretic peptide and vasopressin. Angiotensin stimulates release of aldosterone from adrenal glands, which induces Na+ resorption at the distal end of the tubule resulting to decreased excretion of Na+. Aldosterone and angiotensin have water retention qualities, but the most potent antidiuretic hormone is vasopressin that initiates the formation of aquaporin in the collection ducts (Murdaugh et al., 1961a). During periods of apnea and forced diving, the glomerular filtration rate is reduced while filtration fraction rate remained constant. The behavior is also associated with reduced decrease in urine flow and excreted sodium and chloride (Bradley et al., 1954; Lawrence et al., 1956). Apnea and anoxia have comparable effects on renal hemodynamics in these animals. There is cessation of urine flow and glomerular filtration, which is caused by arterial constriction response. Glomerular filtration reduction corresponds well with decreases in blood flow to the kidneys. The reduction in glomerular filtration rate is a result of regional shunting of blood flow to the away from the kidney. The shunting is an adaptive advantage from the view of decreasing oxygen use by kidneys and increase the delivery of oxygenated blood to other tissues (Ausubel et al., 2002). Water immersions results to diuresis caused by increases in thoracic and arterial pressure (Epstein, 1992). The connection between the cardiovascular system and kidney is known as Henry-Gaur reflex. Pinnipeds spend more time submerged in water, and this could be disadvantageous as result of increased urinary water loss. Pressure impacts of water immersion were simulated in seals by negative pressure breathing meaning indicating Henry-Gaur reflex is absent in seals. These are adaptations to the mammals living in the marine environment(Madigan et al., 1997). Methodologies. A study to investigate the minimum and maximum osmotic pressure threshold that marine animals withstand. The study aims to investigate the maximum threshold of osmotic concentration that marine animals can withstand using their anatomical and physiological adaptations to the marine environment. Marine animals have physiological, anatomical, and behavioral strategies to counter the high osmotic potential in seawater and preserve its bodily water to avoid shrinkage of somatic cells. These adaptations are elaborated in the last century of biological studies and research on marine life. Marine ecosystem has many challenges for the marine life due to ever-fluctuating concentrations of marine life. The fresh water from terrestrial ecosystem, winds, tides, and waves all affect the overall concentration of this marine life. Fresh water from inland rivers dilutes reduces the osmotic potential of the seawater in the nearing seawater compared to the seawater in the in the far most parts of the sea. Marine animals have physiological and anatomical adaptations to high osmotic potential in seawater, but the existence of isotonic or hypotonic environment would be a challenge to avoid cell busting. The marine animals must have physiological adaptations that would allow them to survive under these variations and avoid water intake from hypotonic or isotonic environment that would be lethal to the marine animals (Harvey & Pagel, 1991). The study aims to test marine animals with different concentrations of the water environment and study the minimum and maximum threshold of concentration that marine animals can withstand. Procedure. Marine animals will be subjected hypotonic, isotonic, and hypertonic Na+ and Cl- solutions that will represent the variations that are commonly experienced in marine ecosystems. The survival rate of these animals shall be examined. These will give us an insight of how marine animals can survive the osmotic fluctuations especially for seasonal breeders that travels near fresh water inlets, which are hypotonic relative to their body fluids. The seasonal breeders have behavioral adaptations that allow them to survive the fluctuations that reduce water intake to the body that would lead to cell bursting. The animals shall be divided into seven groups with variations in the osmotic potential represent the variations in the sea. The first group will have the lowest concentration; the fourth group will be the basis of the comparison, and the seventh group will have the highest concentration. The first group will have half the seawater concentration while the seventh group will have twice the osmotic potential of seawater. The animals will remain in the water for 75 hours with close monitoring to establish any behavioral impact to the animals because of the environmental variation. Samples. The marine animals shall be selected from deep sea and interior parts of the sea. These parts of the sea do not often have many variations in water composition. These animals will be ideal to study the osmotic potential stress among marine animals in the dynamic ecosystem. The each group will have ten animals with five different species that will allow comparative analysis. Seventy animals will be trapped from these for the study. The selection will only focus on adults with complete anatomical features, and that are necessary for osmoregulation. Instruments. Marine animals will require sophisticated equipment’s that will enable the capture of these experimental subjects from their natural habitats and their deep sea. Capturing a specific species requires thorough knowledge of the behaviors and habitat preference in the marine ecosystem. These will make it easier for the sample collectors to locate them successfully capture the species of this scientific research. Automated boats will be required for sea navigation and sample collection as well as nets to capture these animals. The nets used should have specifications that target an adult animal only by allowing the young ones to the pass. The aquarium boxes shall be used to handle the animals during the study to allow manipulation of the water environment corresponding the seawater variations. Na+ and Cl- concentrations will be used as the parameters for variation in the seawater osmotic potential. The aquarium will be fitted with automatic thermoregulatory device to ensure temperature parameter is maintained the seawater. All other parameters will be maintained as the seawater to ensure that only the concentration varies. These are to ensure that all observations made from the experiment results from the electrolyte variation of the environment. References. Ausubel, F. M., Brent, R., Kingston, R. E., Moore, D. D., Seidman, J. G., Smith, J. A., & Struhl, K. (2002). Short protocols in molecular biology: a compendium of methods from current protocols in molecular biology (Vol. 2). Wiley New York.  Harvey, P. H., & Pagel, M. D. (1991). The comparative method in evolutionary biology (Vol. 239). Oxford university press Oxford. Holland, J. H. (1975). Adaptation in natural and artificial systems: An introductory analysis with applications to biology, control, and artificial intelligence. U Michigan Press. Madigan, M. T., Martinko, J. M., Parker, J., & Brock, T. D. (1997). Biology of microorganisms (Vol. 985). prentice hall Upper Saddle River, NJ. Retrieved from Strogatz, S. H. (2001). Nonlinear dynamics and chaos: with applications to physics, biology and chemistry. Perseus publishing. Retrieved from Bester, M. N. (1975). The functional morphology of the kidney of the Cape fur seal, Arctoπcephalus pusillus (Schreber). Modoqua Ser. II 4, 69–92. Castellini, M. A., Costa, D. P. and Huntley, A. C. (1987). Fatty acid metabolism in fasting northern elephant seal pups. J. Comp. Physiol. B 157, 445–449. Costa, D. P. (1982). Energy, nitrogen, electrolyte flux and sea water drinking in the sea otter Enhydra lutris. Physiol. Zool. 55, 35–44. Epstein, M. (1992) Renal effects of head-out water immersion in humans: a 15-year update. Physiol. Rev. 72, 563–621 Fetcher, E. S.Jr (1939). The water balance in marine mammals. Q. Rev. Biol. 14, 451–459. Irvine, A. B., Neal, R. C., Cardeilhac, R. T., Popp, J. A., Whiter, F. H. and Jenkins, R. C. (1980). Clinical observations on captive and free-ranging West Indian manatees, Trichechus manatus. Aquat. Mammal. 8, 2–10. Maluf, N. S. R. (1989). Renal anatomy of the manatee, Trichechus manatus (Linnaeus). Am. J. Anat. 184, 269–286. Murdaugh, H. V., Jr, Schmidt-Nielsen, B., Wood, J. W. and Mitchell, W. L. (1961b). Cessation of renal function during diving in the trained seal (Phoca vitulina). J. Cell. Comp. Physiol. 58, 261–265. Ortiz, C. L., Costa, D. and Le Boeuf, B. J. (197). Water and energy flux in elephant seal pups fasting under natural conditions. Physiol. Zool. 51, 166–178. Smith, H. W. (1936). The composition of urine in the seal. J. Cell. Comp. Physiol. 7, 465–474. Read More

These excessive sodium and chloride ions are transported back to the seawater against the concentration gradient. This process uses metabolic energy and linked proteins and the membrane that allows selective passage of unwanted anions and cations. Kidneys filter out the excess Ca2+, Mg2+ and SO42-. The marine osmoconformers regulate their solutes concentrations in their bid to homeostasis. Some organisms have specialized cells in the gills that actively accumulate chlorides and remove them successful from the body system (Madigan, Martinko, Parker, & Brock, 1997).

Literature review. How do marine animals tackle high osmotic pressure in the marine environment? Extensive research has been conducted out to investigate the osmoregulatory mechanisms in the marine environment. Marine animals have specialized kidneys that allow them to inhabit areas of fluctuating concentrations. Members of order Cetaceans (dolphins and whales) have reniculate kidney, that is composed of lobes with discrete cortical tissues and single pyramid made of a single medullary pyramid as a single calyx (Bester, 1975; Vardy and Bryden, 1981).

The kidneys of most marine animals support diving behavior. They have glycogen stores in proximal convoluted tubules. Have high vasa recta bundles and an elastic fiber that separates cortex and medulla (Pfeiffer, 1997). The kidneys of mammalian marine animals have anatomical advancements that enable them to concentrate urine than freshwater and terrestrial animals (Bester, 1975).There is a close correlation between the between medullary thickness and maximum osmolality (Vardy and Bryden, 1981).

Cartilaginous fish such as rays and skates have plasma that s isosmotic to seawater. This high osmotic concentration relative to other vertebrates is achieved by higher levels of urea and trimethylamine oxide in the body fluids (TMAO). The TMAO stabilizes the proteins against the effects of urea. The blood of marine teleost’s are hypotonic to seawater, to replace the lost water; they drink seawater and actively secrete the electrolytes back to the system. Elasmobranchs and marine birds have a salt gland that secretes NaCl from their bodies.

These animals are hypotonic, and this concentration gradient promotes ionic transfer to the body. The sharks have a rectal salt gland which actively secretes this excess salts. Marine birds have salt glands in their skulls while the fish have gills that filter excess salts from their bodies (Strogatz, 2001). Marine animals have ability to excrete highly concentrated urine with high osmotic potential than that of seawater (Bester, 1975; Costa, 1982; Maluf, 1989). This feature is also possible to fresh water inhabitants and is an indication that marine animals can retain this ability in fresh water.

This increase in associated with increased plasma osmolality due to intake of ions. Marine animals do not concentrate urine levels of sodium and chloride to levels above seawater, and this is a clear indication that marine animals do not need to drink seawater to maintain their internal osmolality. Seals and sea lions have advanced ways of osmoregulation in their marine habitat. Seals can maintain their water balance by dietary water and metabolic water (Irving et al., 1935; Smith, 1936; Fetcher, 1939).

Direct intake of seawater is of less importance and probably incidental during feeding. In some species such as Otariids, the water intake depends on ambient temperature as a means to counter thermal stress.In harp seals; ice consumption is common and drinks fresh water greedily when available. Drinking may not be significant, but incidental intake may contribute to electrolyte homeostasis. Diapause is a natural part of pinnipeds, but the time length varies among spices. The low turnover allows them to maintain water balance during a prolonged period of fasting.

The oxidation and fats produce more metabolic water than any other form of oxidation (Ortiz et al., 1978; Castellini et al., 1987). Water needs to be preserved at higher levels during this fasting period to maintain water body contact.

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