There are over 2000 different species of fish in Amazon Rainforest waters. Amazon Rainforest fish are the main source of protein for local Amazon communities and also a main source of revenue. It is almost impossible to visit the Amazon region and not see or hear about fish in some form. The Amazon is home to one of the largest fresh water fish on Earth, the impressively sized Arapaima gigas.
In the dark waters of the Amazon, it helps to see the world in a different way. Electric eels are really knifefish that live in South American waters. They can generate an electrical output of around 600 volts and are consequently regarded as dangerous. The shock is an adaptation to both find food in the water and to defend the fish from predators, which does seem a little overkill. The electrical cells are being studied for their possible use in powering medical implants & small devices. Electric fish also use their shock in mating competitions competing with rival males. Females then choose the male that can generate the highest amount of electricity. When you’re an electric fish, it’s a matter of who has the biggest output.
Oscars are a medium sized fish in the cichlid family. Oscars are found throughout the Amazon basin and the photograph above was taken from a tributary of the Amazon River know as the Rio Tahuayo near Iquitos in northern Peru. If you look closely, you can see a colorful spot just in front of the fish’s tail called an eye spot. Many Amazon insects and animals have this type of marking and what it communicates is still being researched.
On oscars, the eye spot’s size and color closely resembles the fish’s own eye. An idea is that the spots protect the fish from eye-biting animals by making them attack a less important part of the body. Another theory, which has been tested when faced with piranha, is that the spots protect the fish from fin-biting species by confusing predators into thinking the fish has two heads. Another function is to communicate the fish’s health to rivals of the same species and potential mates.
Needle fish are one of the many examples of Amazon Rainforest fish that have many close relatives in ocean waters. Amazon needle fish generally have a greener and murkier coloration to help blend in with Amazon waters as an adaptation to their relatively new environment (from an evolutionary perspective). A predatory fish, they feed on aquatic insects when small and small fish when adult.
Freshwater stingray are something to watch out for when walking in Amazon waters. They prefer shallow areas and are commonly encountered by Amazonian locals. They pack a painful punch if you happen to pose a threat by accidentally stepping near them while you cool your feet from a forest hike. They can grow to over a meter in length, and to give you a clue over how painful their sting actually is, they are known by Amazon locals by their other name, wish-you-were-dead-fish.
Vampire fish are aptly named after their massive fangs at the front of their bottom jaw giving them a scary appearance. They use their teeth to impale other fish as they hunt in the Amazon River and its tributaries.
Arowana fish have a large muscular tail. They use this to jump out of the water in a dramatic display as they attack prey on the water’s surface. Arowanas are carnivorous and feed of manageable prey depending on the fish’s size. Prey range from insects to birds. Arowanas have a primitive lung, which helps them deal with oxygen poor water meaning that they can come to the surface to gulp air.