The color of fish eggs and fish habitat and breeding spawning water environment has a certain connection. Breeding and spawning fish in the ocean, due to more dissolved oxygen in the flowing water, most of the carotenoids in the yolk oxidized to lutein, the eggs are light yellow or white. In the less oxygen-containing still-water ponds and lakes breeding spawning fish, because the carotenoids in the yolk are not fully oxidized to lutein, the eggs are orange-yellow.

Anyone who has observed fish eggs knows that they vary in shade, mostly between orange-red and yellow-white, with a few having other colors.

Why do fish eggs come in different colors?

According to scientists, fish yolk contains an orange-red carotenoid pigment, which easily oxidizes to yellow lutein, which is then reduced to carotenoids in the absence of oxygen. The inter-conversion between the two is related to the supply of oxygen. Some fish eggs are red and some are white, which is related to the environment of the water where the fish live and reproduce to spawn.

In the Yangtze River and other flowing water breeding spawning fish such as green, grass, bighead and silver carp, and in the ocean breeding spawning fish, due to the flowing water contains more dissolved oxygen, most of the carotenoids in the yolk oxidized to lutein, the eggs are light yellow or white, floating on the surface of the water.

In the less oxygen-containing still-water ponds, lakes breeding spawning fish such as carp, crucian carp, etc., because the carotenoids in the yolk have not been fully oxidized to lutein, the eggs are orange-yellow, adhering to the water plants.

The cannabis fish, which breed on the bottom of rivers with sluggish currents, have large pea-sized, orange-red eggs with lots of carotenoids in the yolk, which is apparently related to the fact that the carotenoids are not oxidized to lutein in the presence of even less oxygen in the water.

As for some fish eggs have other colors, such as catfish eggs green, may be slippery and thick secondary egg membrane in the water expansion of the color reflected; sturgeon eggs, the size of green beans, gray-black, may be the secondary egg membrane contains melanin. This egg membrane formed by the green or egg membrane contains pigment masked yolk originally pigment, so that the egg color and the surrounding environment background coordination, the eggs will not be easy to be found by other animals and fish, swallowed or destroyed. This has a protective coloration effect on the reproduction of the fish race.

Fish eggs are rich in protein, especially those with a distinctive color, often tempting appetite. Such as cannabis salmon and sturgeon eggs made of caviar, respectively, called red fish roe and black fish roe, is the table of delicacies and food, sold at home and abroad, quite popular.