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This lateral line enables the fish to sense changes in water pressure and turbulence adjacent to its body. Using this information, schooling fish can adjust their distance from adjacent fish if they come too close or stray too far. [73] The visual system in fish is augmented by other sensing systems with comparable or complementary functions.
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 ...
Freshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands. [1] They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and ...
Conversely, freshwater has less osmolytes than the fish's internal fluids. Therefore, freshwater fishes must utilize their gill ionocytes to attain ions from their environment to maintain optimal blood osmolarity. [6] [10] In some primitive bony fishes and amphibians, the larvae bear external gills, branching off from the gill arches. [11]
Vision is an important sensory system for most species of fish. Fish eyes are similar to those of terrestrial vertebrates like birds and mammals, but have a more spherical lens. Their retinas generally have both rod cells and cone cells (for scotopic and photopic vision), and most species have colour vision.
Swim bladder. The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ that contributes to the ability of many bony fish (but not cartilaginous fish [1]) to control their buoyancy, and thus to stay at their current water depth without having to expend energy in swimming. [2] Also, the dorsal position of the swim ...
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks[a] (/ ˈmɒləsks /). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. [4] The number of additional fossil species is estimated between 60,000 and 100,000, [5] and the ...
An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms — aquatic life —that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. [1]