Fish do tend to sink to the bottom of the water if they stop swimming but most often the fish may only sink a bit when they stop swimming and then begin swimming again so they come back up.
Fish do not die when they stop swimming but when fish die they do sink but then will eventually float back to the surface of the water.
Your average fish can breathe perfectly fine, however, both in motion and at rest, so long as the water is oxygenated sufficiently.
They will not die if they stop swimming.
Simply being in oxygenated water is enough for fish to breathe and survive.
Fish do see in color.
In low light or at night, colors matter less, because fish then rely more on the rod cells in their eyes, which detect contrast and movement but not color.
White, offering the greatest contrast, might well be the color of choice in such situations.
The science says a multi-colored line that blends into the background should be harder for fish to see and track.
While red and green blend well in many situations, blue blends best in offshore waters.
In many cases fish color vision is probably comparable to that of humans.
So you can justify purchasing Uncle Joe's Bass Slayers in all thirty-two available colors!
Like those of humans, fish retinas possess both cones for color vision as well as rods for black and white vision.
A fish is typically pregnant for around 60 days.
Usually, the fish gestation period lasts for 60 days. However, they can fertilize the eggs multiple times, because they store the sperm from the male for months.
Guppies 21-35 days; Platies 24-35 days; Swordtails 28 days; Mollies 50-70 days.
As you can see it can vary considerably, and this depends on the age and size of the fish.
Female fish need to produce so many eggs because of the reproductive strategy in these species results in the highest number surviving to adulthood.
Rather, the rate of predation on fish eggs is high because they produce such a lot of eggs.
Fish first appeared during the Cambrian Explosion Era around 530 million years ago.
The first fish were primitive jawless forms (agnathans) which appeared in the Early Cambrian, but remained generally rare until the Silurian and Devonian when they underwent a rapid evolution.
The Cambrian explosion, Cambrian radiation, Cambrian diversification, or The Biological Big Bang refers to an interval of time approximately 541 million years ago in the Cambrian Period when practically all major animal phyla started appearing in the fossil record.
Cambrian explosion, the unparalleled emergence of organisms between 541 million and approximately 530 million years ago at the beginning of the Cambrian Period.
The event was characterized by the appearance of many of the major phyla (between 20 and 35) that make up modern animal life.
The Cambrian Period marks an important point in the history of life on Earth; it is the time when most of the major groups of animals first appear in the fossil record.
This event is sometimes called the "Cambrian Explosion," because of the relatively short time over which this diversity of forms appears.
Today, scientists have several theories to explain the phenomenon.
One theory is that life may have been able to evolve quickly because the Earth had changed so much that it created enough new niches that species could rapidly fill them.
Given the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion.
It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla.
The event was accompanied by major diversification in other groups of organisms as well.