Search results
Results from the WOW.Com Content Network
Fish vision shows adaptation to their visual environment, for example deep sea fishes have eyes suited to the dark environment. Fish and other aquatic animals live in a different light environment than terrestrial species. Water absorbs light so that with increasing depth the amount of light available decreases quickly.
Organisms at high altitude. An Alpine chough in flight at 3,901 m (12,799 ft) Organisms can live at high altitude, either on land, in water, or while flying. Decreased oxygen availability and decreased temperature make life at such altitudes challenging, though many species have been successfully adapted via considerable physiological changes.
Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many ways, especially the difference in levels of osmolarity. To survive in fresh water, fish need a range of ...
Ray finned species, with spiny fins, are rare among deep sea fishes, which suggests that deep sea fish are ancient and so well adapted to their environment that invasions by more modern fishes have been unsuccessful. [18] The few ray fins that do exist are mainly in the Beryciformes and Lampriformes, which also are ancient forms. Most deep sea ...
But even so, there can be unusual adaptations. Four-eyed fish have eyes raised above the top of the head and divided in two different parts, so that they can see below and above the water surface at the same time. Four-eyed fish actually have only two eyes, but their eyes are specially adapted for their surface-dwelling lifestyle.
By the Upper Devonian period, the fin-limb transition as well as other skeletal changes such as gill arch reduction, opercular series loss, mid-line fin loss, and scale reduction were already completed in many aquatic organisms. [ 3] As aquatic tetrapods began their transition to land, several skeletal changes are thought to have occurred to ...
Secondarily aquatic tetrapods. Several groups of tetrapods have undergone secondary aquatic adaptation, an evolutionary transition from being purely terrestrial to living at least part of the time in water. These animals are called "secondarily aquatic" because although their ancestors lived on land for hundreds of millions of years, they all ...
Aquatic respiration. Sea slugs respire through a gill (or ctenidium) Aquatic respiration is the process whereby an aquatic organism exchanges respiratory gases with water, obtaining oxygen from oxygen dissolved in water and excreting carbon dioxide and some other metabolic waste products into the water.