Salmon is a river fish.
Female Pacific salmon lay eggs once in their lifetime, then
die a few days or weeks after ovulation, so they are known to be monogamous,
and their decomposing bodies nourish the delicate plants and animals that young
salmon will feed on after hatching for a period of one to three months. Months,
female Atlantic salmon females can ovulate more than once.
Female salmon lay between 2500-7000 eggs, depending on the
type of fish and size, and the color of eggs ranges from orange to red, and
fertilization takes place in the water where the male secrete the semen to
fertilize them, then the females cover the egg gravel to protect it.
Small salmon fish gradually develop through their ability to
live in salty ocean waters, they spend between one to three years in fresh
water, and then they start their migration as their body chemistry changes to
become more adapted to salt water, and they spend part of their migration time
in moderate waters. Salinity; until she gets used to regulating the osmotic
pressure of her body before she reaches the extremely salty ocean water.
The age of salmon fish ranges between two to seven years,
depending on the type, and the age of the salmon can be determined by the
number of growth rings on its scales using a microscope, and these rings are
similar to the growth rings that appear on the trunks of trees, and are
characterized by the growth rings formed during their years of living in Fresh
water is close and crowded, but the growth episodes that appear while living in
salt water are more distant from each other.
Small salmon fish feed on insects, snails, and other
crustaceans, while older fish feed on other fish. Salmon fish are exposed to
many threats to their lives, such as: predators, and changes in their habitat
due to the influence of human activity, such as: silt accumulation, low oxygen
concentration, high water temperature, and low water flow in rivers.
Salmon fish depend on the sense of smell to know the way
they migrated from the ocean to the river where they were born, and there is at
least one type of salmon, which is the Sukai salmon, that can infer its way of
migration by sensing the differences in the magnetic field of the earth.
إرسال تعليق