The earth has been around for a very long time and since the earliest days of life on our planet, there has been a scramble to fill various ecological niches.
There are those that have adapted to survive in the depths of the ocean, those that make their living on the highest mountain tops, but among the strangest of the living creatures of the world are those that live in the waterways of rivers.
This is not because rivers are somehow a completely different entity than the rest of the geographic or environmental landscapes on our planet, but they are some of the oddest.
A torrent of fresh, shallow water, moving through the landscape, will always make for some amazing and strange creatures.
To start this list, we start with one of the most impressive and most terrifying hunters in the world: the Green Anaconda.
This snake is definitely the heaviest and the second-longest snake in the world, beaten out by the Reticulated Python of Southeast Asia.
Although it isn’t the longest, it is impossible to determine how long it can actually get, due to the murky Amazon waters in which it makes its home hiding many individuals of the species.
While it does not consume large prey regularly, it will take down almost anything in its territory, including peccaries (a type of large pig) and tapirs.
The only animal that is somewhat safe is the Jaguar, due to their powerful physique and bite.
It will wrap its huge body around the victim and strangle them to death, before consuming the body whole.
This powerful predator has become a cultural icon and has inspired movies and folklore with just its presence alone.
Another famous resident of the world’s waterways, Electric eels are not actually true eels, they are in fact more closely related to Catfish, which – from their looks – actually makes sense.
Their electrical capabilities are no joke either, with the eel using three different organs on the body that can emit electrical discharges at varying voltages: a low voltage discharge for electrolocation and high voltage discharges to stun prey and defend themselves.
In fact, study of the electric eel’s electric organs led to the development of the first electric battery.
The discharge and voltage of the electric eel’s attack is similar to a stun gun or a light tasing, which is enough to stop a human in their tracks for a few moments.
Since the electric eel hunts much smaller prey, this would be an incredibly powerful weapon that probably kills or completely immobilizes the animals it hunts.
Strangely enough, the electric eel is also an air breather, but it doesn’t have lungs, like the bichir fish.
Instead, it will gulp down air every 10 to 12 minutes and the oxygen will be absorbed directly into the bloodstream.
Moving away from powerful and terrifying carnivores and moving on to just powerful carnivores, we have the otter.
Otters reside in most of the world’s fresh waterways and provide the bulk of the mammalian carnivore presence to those living there.
They have long, slim bodies and fairly short limbs, with powerful webbed feet and an ability to hold their breath for long periods.
All these make the otter an incredibly powerful swimmer, and they are hard to spot once they are in the water.
Otter’s primarily eat crustaceans and amphibians, but have been known to take any small prey, like fish, that enters their range.
The problem for otters is that most of their food is not calorie rich and, due to having self-warming bodies while swimming in cold waters, they must constantly find food in order to survive.
Often, an otter will have to eat between 15% to 20% of their own body weight each day to survive.
Otters can be solitary creatures or live in close-knit familial groups, but the solitary ones often have territory overlapping with other ‘friendly otters’.
For example, a male Eurasian otter’s territory may overlap with a female Eurasian otter’s territory, because she isn’t a threat to him, and so they may interact on occasion.
While some rivers may have a resident super predator, like the Anaconda, most waterways in the world give way to the royalty of the rivers: Crocodiles.
The members of the Crocodilian family are the closest living relatives of birds, which makes them as old or older than the dinosaurs themselves.
They are truly enormous reptiles with the smallest – the dwarf crocodile – being between 5 and 6 feet and the largest – the saltwater crocodile – growing up to 20 feet and weighing close to 2000 pounds.
These animals have incredible senses, even hearing, which is unusual for a reptile, and have perfected their hunting strategies.
Sometimes they will wait, conserving energy with their head floating above the surface. They can wait for days, weeks, even years at a time for prey to show.
When they do settle in to drink from the river, as large bovines that they hunt tend to do, a crocodile will strike, clamping down on their neck with the most powerful bite force that we currently know of before dragging them into the water and drowning them.
The animal and method of hunting may change per species of crocodile, maybe they will pursue their prey or dig them out from their hiding hole, but the bite is always consistent.
For those they can’t drown, they will either tear apart or swallow them whole.
Surprisingly, considering the brutal ways they kill, these reptiles are actually the most social of all reptiles.
They will not form groups, but they will congregate in the same area, either to feed, bask, or mate.
They will even rear their young, which is highly unusual for reptiles, and they have the most advanced social calls of reptiles.
Animals that live in rivers can display some strange and wonderful characteristics, but all of them are important for their continued existence in one of earth’s most unusual habitats.