The arapaima, a gigantic carnivorous, air-breathing fish that lives in the rivers and swamps of the Amazon Basin, is so well equiped that even it's tongue has teeth!

The arapaima, a gigantic carnivorous, air-breathing fish that lives in the rivers and swamps of the Amazon Basin, is so well equiped that even it's tongue has teeth!... plus 3 other Interesting Animal Facts.

The heavily armoured scales of the fish enables it to live in piranha-infested lakes, where no other animals would survive. Ironically, since it does tend to live near the surface, it also means it's easy prey for human predators.

The tongue of this fish is thought to have medicinal qualities in South America. It is dried and combined with guarana bark, which is grated and mixed into water. Doses of this are given to kill intestinal worms. In addition, the arapaima's bony tongue is often used to scrape cylinders of dried guarana, an ingredient in some beverages, and the bony scales are used as nail files.

Pyura chilensis, a sea creature that lives on the rocky coast of Chile and Peru, could make that popular saying "You can't get blood out of a stone" seems like, well - false! These non-moving, sac-like marine invertebrate filter feeders which eats by sucking in seawater and filtering out microorganisms, look like rocks upon first glance until you cut them open to reveal a bright red flesh.

Credit: Arvid Puschnig

This 'animals' have clear blood and can also breed with itself.

In Chile, they are fished commercially, and the locals eat them raw or cooked with salad and rice because apparently they’re delicious even thought they contain high concentration of vanadium, up to 10 million times that of the surrounding seawater. Vanadium is a heavy metal considered toxic at any more than incidental levels. Just why and how these creatures are able to accumulate vanadium in such huge quantities remains unknown.

Bonobos mating, Jacksonville zoo, FL.
Pic source

Bonobos are the only non-human animals to have been observed engaging in all of the following sexual activities: face-to-face genital sex (though a pair of western gorillas has been photographed performing face-to-face genital sex), tongue kissing, and oral sex. Sexual activity generally plays a major role in bonobo society, being used as what some scientists perceive as a greeting, a means of forming social bonds, a means of conflict resolution, and postconflict reconciliation - in other words, sexual activity plays a role in every aspect of their lives.

They live in the Congos and are not in too many zoos for obvious reasons.  Their sexual behaviour is said to be too human-like for most of us to be comfortable with.

“We have a lot to learn from [bonobos], because they’re a very egalitarian society and they’re a very empathetic society. Sexual behavior is not confined to one aspect of their life that they set aside. It permeates their entire life.” - Susan Savage-Rumbaugh

Bonobos do not form permanent monogamous sexual relationships with individual partners. They also do not seem to discriminate in their sexual behavior by sex or age, with the possible exception of abstaining from sexual activity between mothers and their adult sons. When bonobos come upon a new food source or feeding ground, the increased excitement will usually lead to communal sexual activity, presumably decreasing tension and encouraging peaceful feeding

The Water Holding Frog or Litoria platycephala, has the unique ability to gain 50% of it's body weight in water and go into a sort of self-induced coma which therefore enables it to live where no other amphibian would dare to - the dry, sandy outbacks of Australia which gets less than 12 inches of rain a year. But how it uses this unique ability to survive in such arid conditions is even more fascinating.

After filling itself up with water during a wet season, the frog then burrows itself underground up to depths of over 1 meter (3 ft.)!  The frog then creates a burial-like chamber by shedding it's skin in one piece and cocooning itself inside of it as it prepares to go into a coma-like state until the next rainy season.  They have been known to live underground without food or water for up to 2 years or more! However, for additional nutrition and to save energy, the frog will eat this external skin.

Australian Aborigines discovered a means to take advantage of this by digging up one of these frogs and squeezing it, causing the frog to empty its bladder. This dilute urine--up to half a glassful--can be drunk. However, this will cause the death of the frog which will be unable to survive until the next rainy season without the water it had stored.