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Inbreeding in fish is the mating of closely related individuals, leading to an increase in homozygosity. Repeated inbreeding generally leads to morphological abnormalities and a reduction in fitness in the offspring. In the wild, fish have a number of ways to avoid inbreeding, both before and after copulation.
Then take a small glass dish, fill it with water and move the dish back, and at subsequent meal times bring it nearer and nearer to him. Again in three or four days the small glass dish can be put on the tray alongside of his milk. The old fear has been driven out by training, unconditioning has taken place, and this unconditioning is permanent.
Because of this, there are generally more males available to mate at a given time, making females a limited resource. [4] [5] This leads males to evolve aggressive mating behaviors which can help them acquire mates. [5] Sexual coercion has been observed in many clades, including mammals, birds, insects, and fish. [6]
Their levels of aggression increase more when the rates of sneaking by rival males go up too. The sneaking males enter the nest and release their own sperm over the eggs of the breeding fish. The rival fish here are using alternative reproduction methods like parental, sneaker or satellite to avoid being hurt by breeding males. On the other ...
Chum salmon is a typical cold water fish that prefer water around 10 °C (50 °F). When water temperature is raised due to thermal pollution, chum salmon tends to dive into deep water for thermoregulation. This reduces the time chum salmon spent in surface water column and reduce the chance for chum salmon to approach natal river since the ...
The different mechanisms of outbreeding depression can operate at the same time. However, determining which mechanism is likely to occur in a particular population can be very difficult. There are three main mechanisms for generating outbreeding depression: Fixed chromosomal differences resulting in the partial or complete sterility of F 1 ...
Filefish spawn at bottom sites prepared and guarded by the males; both he and the female may guard the brood, or the male alone, depending on the species. The young filefish are pelagic; that is, they frequent open water. Sargassum provides a safe retreat for
A deep bodied, laterally compressed fish with a blunt snout. [1] [2] Spineless dorsal fin with the posterior ray developed into a long filament. [1] Usually silver overall, sometimes grey to greenish dorsally. [1] In Victoria it has been reported to develop a rusty red tinge especially around the mouth [2] which is thought to be related to ...