Melothria scabra is a species of cucurbitaceous vine grown for its edible fruit, known as cucamelon. Cucamelons are about the size of grapes and taste like cucumbers, they are notable for their sour aftertaste that comes from the skin.

The M. scabra plant is native to Mexico and Central America, where it is called sandíita (little watermelon). It is believed to have been a domesticated crop before western contact began.

If you happen to get your hands on these tiny melons, apparently they are terrific in stir-fries; they can be pickled just like French gherkins, eaten raw in salads or put up like Polish dill pickles. They also can be chopped and added to salsas for extra texture and flavor. ...

The poison dart frog is the common name given to the most poisonous animals on Earth.

Native to Central and South America, these species of frogs (family: Dendrobatidae) produce several lethal toxins that are capable of killing a human or other large animal with just 2 micrograms (μg). In other words, one drop of their venom could be powerful enough to kill 8000 people.

The most toxic of poison dart frog species is Phyllobates terribilis. Unlike snakes, dart frogs do not synthesize their poisons, but sequester the chemicals they consume from arthropod prey, such as ants, centipedes and mites. This is why in captivity, they produce far less poison than wild frogs due to their change in diet. What makes these frogs immune to their own poison i ...

The coconut crab (Birgus latro) is a species of terrestrial hermit crabs that's known for the largest land-living arthropod in the world, weighing up to 4.1 kg (9.0 lb). It is found on islands across the Indian Ocean and parts of the Pacific Ocean, mirroring the distribution of the coconut palm. Like other hermit crabs, juvenile coconut crabs use empty gastropod shells for protection, but the adults develop a tough exoskeleton on their abdomen and stop carrying a shell.

Coconut crabs have evolved organs known as branchiostegal lungs, which are used instead of the vestigial gills for breathing. They cannot swim, and will drown if immersed in water for long. They have also developed an acute sense of smell, which has evolved convergently with ...

The Mexican tetra (Astyanax mexicanus) is a blind, freshwater cave fish native to central and eastern parts of Mexico. Growing to a maximum total length of 12 cm (4.7 in), this species is notable for having no eyes or pigment; it has a pinkish-white color to its body (resembling an albino).

The Mexican tetra spends most of its time in midlevel water above the rocky and sandy bottoms of pools and backwaters of creeks and rivers of its native environment. Coming from a subtropical climate, it prefers water with 6.5–8 pH and a temperature range of 20 to 25 °C (68 to 77 °F). In the winter, some populations migrates to warmer waters. Its natural diet consists of crustaceans, insects, and annelids.

Given their peaceful nature, this species is popu ...

Some mammals, such as camels, polar bears, and seals, have full nictitating membranes. That is the transparent or translucent third eyelid that can be drawn across the eye for protection and to moisten it while maintaining visibility.

In humans, the plica semilunaris (also known as the semilunar fold) and its associated muscles are thought to be homologous to the nictitating membranes seen in other animals. In most primate species, a plica semilunaris is present, but a fully developed nictitating membranes still exists in lemurs and lorisiform primates.

Unlike the upper and lower eyelids, the nictitating membrane moves horizontally across the eyeball (shown below). In some diving animals, such as beavers and manatees, it moves across the e ...

Birds are very clever animals. They exhibit a wide range of smart behaviors, including good memories, extensive communication, planning for the future, and remembering the past. Some birds can solve problems, and others are capable of adapting to new environments and conditions.

Experts often think of intelligence in terms of creative abilities used to solve problems. Some scientists believe that tool-using birds show such abilities. The woodpecker finch (first from left) of the Galapagos Islands, for example, has learned to use a cactus spine or small twig as a probe to remove carpenter bee larvae from their tunnels. The Egyptian vulture (second from left) uses rocks to break open ostrich eggs. Gulls learn to drop clams and turtles onto roc ...

Did you know that the Moon's rotation is locked to its orbit around Earth by a bulge of material under the Moon's surface? This material is denser than the rest of the Moon's surface material, and Earth's gravity pulls on it especially strongly. The side of the Moon containing the bulge always faces Earth. We call it the near side and we call the other side, which we never see from Earth, the far side. People often mistakenly use the term "dark side" when referring to the far side of the Moon, forgetting that the far side is fully illuminated by the Sun whenever we see a new moon from Earth.

If we were to look from high above the Earth-Moon system, we would see the Moon rotate once per month with respect to the stars. This is its sidereal ro ...