Light sensitivity of fish
The researchers published two scientific fields interesting results. Scientists have discovered one of the directions of the presence of light-sensitive cells in different areas of the skin and in the so-called “third eye”.
Other scientists studying biorhythms, revealed the presence in fish of the biological clock, due to which the fish are well oriented in time, their error is not more than 10Minutes per day.
But the first group of scientists studying light-sensitive cells that did not respond to the question “What are they for the fish?” It should be noted that such cells were found in organisms, such as worms. They found the rudiments of the organ of vision. They are found in the retina of the human eye, but their purpose was also no explanation.
A second group of researchers is not explained by what specifically triggered the biological clock fish. Everything will fall into place, if you imagine that with these light-sensitive cells and start the biological clock of living organisms, or they themselves, and are these hours.
It is believed that the reaction of the luminous flux – the main function of this body. It also plays an important role in determining the duration of the daily changing of illumination depending on the position of the Earth relative to the Sun regions.
The biological clock of living organisms work on their own, they are focused on specific uniformly applicable external sources, which should have the constancy of action and strong rhythm.
Of the known factors is such a spendthrift being only three: light, temperature and gravity. In this particular case, the light-sensitive cells respond to light. Fish must perceive light output regardless of weather and light conditions.
To do this they needed, and the entire surface of the body, “the third eye”, not only the eyes, which in the conditions of their existence would be beyond the power to perform this function. The body reacts to the light sensitivity of the light changes the climate, the light intensity.
It starts or suppresses the activity of individual physiological systems of fish, their biorhythms. His primary duty – to bring all the life processes of fish in accordance with the calendar, the timely activation and deactivation of certain internal processes, rational for seasonal behavior.
Naturally, this body works closely with the other senses, and, above all, vision and thermo receptors. To set your biological clock, fish, like most living organisms, using periodic light signals (dawn, sunset), which allow them to synchronize their internal rhythms with the rhythms of the surrounding environment.
As these signals, called synchronizers, or time sensors used alternation of day and night. The presence of the body of fish is confirmed by many examples of fishing practices. For example, in late winter – early spring, when the warm water still does not flow under the ice, and the day has increased significantly, the fish begin to be active – acting light factor, vision here is not significant, as the temperature factor.
What practical applications could be our knowledge of the work of this body? With it, the fish clearly commensurate with their behavior given the nature of their routine for the duration of their existence.
We, apparently, it’s time to move on to more precise measurements of the time of their routine. For example, today we say that biting large carp begins and ends before sunrise. The time will come and we shall say that the bite of the same carp begins 30 minutes and ends 10 minutes before sunrise.
Or, adult pike eats a 2-allotment rhythm. Preferably from 3 to 8 and 17 to 20 day lunar calendar. Or that growing fish, the main subject of our catch, eat in a 90-minute rhythm. Time in the above examples of course approximate.