The reason why sea turtles cry
With the development of science, the mystery of the tears of sea turtles has been revealed. It turns out that sea turtles excrete excess salt from the body in this way to achieve the balance of salt in the body.
Sea turtles mainly live in the sea, surrounded by salty and bitter sea water. The food they often eat is small fish, shrimp, crabs, jellyfish and seaweed living in the sea environment. These foods contain a lot of salt. Sea turtles can accumulate large amounts of salt in their bodies by drinking sea water and eating food. Too much salt accumulating in the body is harmful to the body, and the kidneys of sea turtles have very poor concentration ability, so the amount of salt that can be excreted is very limited. Fortunately, they have an organ called “salt gland”, which is responsible for expelling excess salt from the body to achieve the balance of body salt. Since the salt glands of sea turtles are located at the back of the eyes, which originally belonged to the lacrimal glands, when the salt glands are expelling excess salt from the body, they look like they are weeping.
Turtles live in the sea most of their lives. They only come to the coast when they perform certain life activities, such as laying eggs. Then we can observe them up close. This may be why we often think that sea turtles are after laying eggs. It’s because of “tears”.
In fact, seabirds that feed on marine organisms also need to excrete salt, but this organ is in the nasal cavity. Of course, because seabirds do not drink sea water, we cannot see that they often have runny noses.
The morphological characteristics of sea turtles
Carapace is olive green or brown when living, mixed with yellow-white radiation patterns. The plastron is yellow. The head and limbs are tan. Specimen SMNH785007 is a young turtle that has just hatched. The carapace is brown-black, with 3 ribs, obvious ribs, lighter color and weaker side ribs. The plastron is yellow-white, with a distinct longitudinal edge on each side of the belly; the umbilical hole is located in the central part of the seam between the abdominal shield and femoral shield.
Life habits of sea turtles
Live in the ocean for life. Feeds on fish, cephalopods, crustaceans and seaweed. The breeding season is from April to October. Female and male turtles often mate on reefs or coastal waters. The mating time is as long as 3-4 hours. After mating, female turtles climb on the beach at night to dig pits to lay eggs. A large pit with the same depth as the body height, lay down in the pit, and then dig an “egg pit” with a diameter of 20cm and a depth of about 50cm with the alternating movement of the hind limbs. After the eggs are laid, cover the egg pit with sand and leave the beach to return to the sea. It can lay eggs 23 times a year, 91-157 eggs per year, up to 238 eggs. Egg white, spherical, leathery and soft, egg diameter 35-58mm. The hatching period is 30 to 90 days, usually 45 to 60 days. The young turtles crawl back to live in the sea after they emerge from their shells. The coasts of Huidong in Guangdong Province and the Paracel Islands in Hainan are sea turtle spawning breeding grounds.