Sharks are color blind
At the University of Queensland examined the eyes of the shark and came to the conclusion that those deprived of color vision.
The research object of scientists were 17 species of sharks. During microspectrophotometric analysis, it was found that 10 of them were no cones, intended for color vision, and their role was partially assumed the highly sensitive sticks. The remaining seven species that belong to three different families, had one type of sensing elements designed to detect wavelengths from 532 to 561 nm.
It is known that whales, dolphins and killer whales also stick with the cones of one type, which is able to recognize green color. Continue reading
In the waters of the Gulf of Thailand is inhabited by many species of jellyfish, most of them pose no danger to the bather. However, occasionally there occur and deadly members of this family — jellyfish. This jellyfish cylindrical body and a very long blue or blue tentacles (length of tentacles of some species of jellyfish reaches 4-5 meters). In August and October of 2015 near the Islands of Samui and Phangan were registered two fatal accidents with the girls who decided to go swimming at night and saw the presence in the water of this dangerous jellyfish.
If you are going to swim in the sea, pay attention to the coastal strip. If the sand contains up washed up jellyfish, so you should be doubly careful when bathing. As a rule, jellyfish that can sting you, quite visible in the water because of their dark or bright color (transparent jellyfish are not dangerous to the bather). But the situation may be complicated by the agitation of the sea, or opaque because of suspended sand in the water. It is especially dangerous to bathe in the dark. Continue reading