It also acts as a type of lubricant to reduce friction in the water allowing easier movement through the water. Swim Bladder The swim bladder is an organ found inside the fish. This organ is used to help the fish sink or float in the water. The bladder fills with air if it wishes to float, and reduces air when it wishes to sink. Without this bladder, the fish would have to constantly swim in order to not sink to the bottom.
Dissolved oxygen is absolutely essential for the survival of all aquatic organisms, and thus these two variables have a definite relationship with another. (5.2 Dissolved Oxygen) Total dissolved gas concentrations in water should not exceed 110 percent. Concentrations above this level can be harmful to aquatic life. Fish in waters containing excessive dissolved gases may suffer from "gas bubble disease". Aquatic invertebrates are also affected by gas bubble disease but at levels higher than those lethal to fish.
They pump blood into the foot, causing it to swell and to act as an anchor in mud or sand. Then, longitudinal muscles contract to shorten the foot and pull the animal forward. Osmoregulation: They are isosmotic. This means that they have the same level of osmotic pressure diffusing and the solvent flows through a semi porous membrane from a region of low solute concentration to a region of high solute concentration. Therefore, they can inhabit, adjust and sustain stability in their new environment when migrating.
Keratin, in abundance in this outer layer, waterproofs the body. Without it, handling household chemicals, swimming in a pool, or taking a shower (a necessary everyday activity) would be disastrous to the underlying cells of the body. Not only does keratin keep water out, it also keeps water in. Excessive evaporation or loss of body fluids would result in dehydration and eventual death. Body temperature The heat-regulating functions of the body are extremely important.
Whether the stomata opens or closes depends on changes in the turgor of the guard cells. When osmosis causes water to flow into the guard cells, their turgor increases and they expand. Due to the relatively inelastic inner wall, the guard cells bend and draw away from each other, so the pore opens. If the guard cells loose water the opposite happens and the pore closes. The guard cells lower their water potential to draw in water from the surrounding epidermal cells, by actively accumulating potassium ions.
Most animals need to stay at roughly the same temperature so heat is also exchanged. The larger the surface area to volume ratio is the easier it will be for the animals to perform these exchanges. Gas exchange surfaces have to main adaptations, large surface area and they are thin, they will both increase the rate of diffusion. Single celled organisms don’t require gas exchange systems because they can absorb and release gases by diffusion through there outer surface because they have a relatively large surface area. Large organisms require gas exchange systems to acquire all the oxygen they need, fish for example have special adaptations because there is less oxygen in the water than in the air.
We know this thanks to preservation of soft tissues found on some trilobite fossils. The same fossils are also found in freshwater environments, suggesting that some freshwater trilobites existed among saltwater trilobites. Up to the late Devonian Period they were very diverse, and likely there were trilobites that specialized in most every type of marine food source. Some definitely burrowed in the mud of the sea bed, likely eating anything they found there. Others would have been active predators and hunted other trilobites, worms, etc.
Octopuses are one of the most interesting sea creatures. Name octopus is derived from a Greek language and it means eight-footed. There are over 200 species of octopuses and all of them live in oceans around the world, usually near the coral reefs. Octopuses are invertebrates, which mean that they are boneless. Because of that, octopus loses its shape when it is pulled out of the Octopi have arms, not tentacles.
Microorganisms are classified by their optimum growth temperature. Microorganisms can be classified as psychrophiles, mesophiles, thermophiles, and hyperthermophiles, and each classification has its own set of special characteristics. If a microbes cell is in a solution in which the concentration of solutes is higher than that found in the cell, cellular water passes through the cytoplasmic membrane in the direction of the high solute concentration. During the loss of water, the cytoplasmic membrane collapses away from the cell wall, which is called plasmolysis. Extreme halophiles (sometimes called obligate halophiles) are organisms
A large majority of Earth’s biomass consists of plankton floating in the oceans. Phytoplankton can be divided into three groups of microscopic algae: Diatoms, Coccolithophores, and Dinoflagellates. Diatoms are a type of algae that are enclosed in a microscopic shell called a test. These tests are important because they accumulate on the ocean floor, which produces siliceous sedimentary rock that is used to make various household items. Coccolithophores are covered in coccoliths which are small calcareous plates made of calcium carbonate.