The tuatara, a reptile found in New Zealand, has a partial third eye, also known as a parietal eye, on top of its head. This eye has a retina, lens, cornea and nerves, but it isn't used for sight.
Scales grow over the third eye of the tuatara in its first six months. This prevents the eye from being used as a sight organ, but it is still light sensitive. The purpose of the third eye isn't well understood, but it may help the tuatara to regulate its body temperature, absorb ultraviolet radiation for vitamin D synthesis and regulate its circadian rhythm.Learn More
Most extinctions can be prevented by implementing conservation strategies such as legal remedies, preserving natural plant and wildlife habitats and using synthetic medicines not derived from plant and animal products. Preventing extinction requires an understanding of its root causes, which include natural events and human activity. Although extinctions from natural causes cannot be prevented, human behavior may be modified to give flora and fauna worldwide a greater chance of survival.Full Answer >
There are over 180 species of earthworms in the United States and Canada, but only 60 of these are native to the area. Settlers brought many of the species to improve the soil, although earthworms are not always beneficial to plants.Full Answer >
Sand dollars are actually the skeletons of marine echinoderms and take their off-white, chalky form after the animal dies. They are closely related to flat sea urchins, starfish and sea cucumbers. When alive, they are covered in short, fine spines and range in color from yellow to blue and purple.Full Answer >
Remora and sharks have a commensalism relationship which, according to the Encyclopedia Britannica, is a relationship between two species in which one benefits from the other without either being harmed. Commonly called a suckerfish, the remora is a pelagic marine fish that attaches to the shark and feeds on it. Unlike parasitic species, the remora does not penetrate the flesh of the shark or otherwise cause it damage.Full Answer >