Search results
Results from the WOW.Com Content Network
Fish born in different regions will show clear differences here. Studies of the commercial fishing industry in the United States show that the population of bluefin tuna in the North Atlantic is made up of fish hailing from both coasts. While the fish may live in close proximity out in the Atlantic, they return to their natal region to spawn.
Salmon are typically anadromous: they hatch in the shallow gravel beds of freshwater headstreams and spend their juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea fish, then return to their freshwater birthplace to reproduce. However, populations of several species are restricted to fresh ...
Juvenile fish are marketed as food. Whitebait is a marketing term for the fry of fish, typically between 25 and 50 millimetres long. Such juvenile fish often travel together in schools along the coast, and move into estuaries and sometimes up rivers where they can be easily caught with fine meshed fishing nets.
A grizzly bear ambushing a jumping salmon during an annual salmon run. A salmon run is an annual fish migration event where many salmonid species, which are typically hatched in fresh water and live most of their adult life downstream in the ocean, swim back against the stream to the upper reaches of rivers to spawn on the gravel beds of small creeks.
Coelacanth eggs are large, with only a thin layer of membrane to protect them. Embryos hatch within the female and eventually are born alive, which is a rarity in fish. This was only discovered when the American Museum of Natural History dissected its first coelacanth specimen in 1975 and found it pregnant with five embryos. [69]
The surfperch, genus Embiotoca, is a saltwater fish with a gestation period of three to six months. [13] This lengthy period of pregnancy gives the family its scientific name from the Greek "embios" meaning "persistent" and "tokos" meaning "birth". The table below shows the gestation period and number of young born for some selected fish.
In ovoviviparous fish the eggs develop inside the mother's body after internal fertilisation but receive little or no nourishment directly from the mother, depending instead on a food reserve inside the egg, the yolk. [10] Each embryo develops in its own egg. Familiar examples of ovoviviparous fish include guppies, angel sharks, and coelacanths.
The fertilized eggs float close to the surface, carried by the currents, and hatch in 15 days. Before hatching the eggs sink to the bottom. Before hatching the eggs sink to the bottom. For the next four to six months baby flounders float in the open ocean , sometimes hundreds of miles from the place the eggs were released and hatched.