Search results
Results from the WOW.Com Content Network
A fish ladder, also known as a fishway, fish pass, fish steps, or fish cannon, is a structure on or around artificial and natural barriers (such as dams, locks and waterfalls) to facilitate diadromous fishes' natural migration as well as movements of potamodromous species. [1] Most fishways enable fish to pass around the barriers by swimming ...
A fish hatchery is a place for artificial breeding, hatching, and rearing through the early life stages of animals—finfish and shellfish in particular. [1] Hatcheries produce larval and juvenile fish, shellfish, and crustaceans, primarily to support the aquaculture industry where they are transferred to on-growing systems, such as fish farms ...
A fish (pl.: fish or fishes) is an aquatic, anamniotic, gill-bearing vertebrate animal with swimming fins and a hard skull, but lacking limbs with digits.Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as well as the extinct placoderms and acanthodians.
In archeological literature, the name Boylston Street Fishweir refers to ancient fishing structures first discovered in 1913, buried 29 to 40 feet (8.8 to 12.2 m) below Boylston Street in Boston, Massachusetts. Reports written in 1942 [1] and 1949 [2] describe what was thought to be remains of one large fishweir, 2,500 years old, made of up to ...
Bubble nests, also called foam nests, are created by some fish and frog species as floating masses of bubbles blown with an oral secretion, saliva bubbles, and occasionally aquatic plants. Fish that build and guard bubble nests are known as aphrophils. [1] Aphrophils include gouramis (including Betta species) and the synbranchid eel Monopterus ...
Fish gill. Gill arches bearing gills in a pike. Gills allow fish to breathe underwater. Respiratory mechanism in bony fish. The fish draws oxygen-rich water in through the mouth (left). It then pumps it over gills so oxygen enters the bloodstream, and allows oxygen-depleted water to exit through the gill slits (right) Fish gills are organs that ...
Thomas Aldwell ignored this requirement. Fish Commissioner Leslie Darwin offered to waive that requirement if Aldwell built a fish hatchery adjoining Elwha Dam. Although Aldwell initially balked at this proposal, he did build a fish hatchery that began operation in 1915. [7] The hatchery was a fiasco. Its managers were unable to successfully ...
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 ...