Freshwater aquaria

The fish exhibited in freshwater aquariums come from four regions of the world: South America, northeastern Asia, Australia, and eastern Africa. Amazonia, the Gdynia Aquarium's newest exhibit, is located on the ground floor of the rotunda. The four huge biotope aquariums were created and stocked to mirror the natural environment of the Amazon River basin. The exceptional visual effects achieved in this exhibit are thanks to acrylic screens that give visitors the impression that they are at once under water and just above the water surface. Paludariums are tanks that incorporate both terrestrial and aquatic environments, and they present the animals and plants of South America.

The largest paludarium is home to two green anacondas and a school of colorful oscars. The anacondas were housed previously in a paludarium on the second floor, and before the opening of the new exhibit, they had to move house. The anaconda move was directed by one of the Aquarium's qualified specialists, and the whole escapade was photographed and filmed.
Anacondas are amphibious, and their natural habitats include wetlands and rivers. They prefer hunting at night just beneath the water surface, with only their head emerged as they lie in wait for their prey. Once they have caught their victims, they wind around them constricting them with their strong bodies.
The other tanks house the silver arowana and arapaima, which are among the world's largest freshwater predatory fish. Swimming right in front of the visitors' eyes, these fish are always at the ready to leap out of the water and seize their prey.
You will also see a school of red piranahs up close as they keep their keen eyes trained on their surroundings. These are known to be the most bloodthirsty of fish; just have a look at their sharp teeth.
The last open tanks is inhabited by the beautiful and dangerous river stingray and the sparkling freshwater silver dollar fish.
     

 

To see more freshwater creatures, go to the exhibit named Between Water and Land on the second floor. The tanks here are a combination of aquariums and terrariums, and they house a host of animals that live between the water and the land. While most of these animals are various species of reptiles, you'll also see some fish there.

The electric eel tank is a real attention grabber. Although these fish appear to be harmless, they can create an electrical charge of 300 to 600 volts at an intensity of 1 amp; in other words, enough electricity to kill a person! The organs that generate the electrical charge comprise several thousand electrocytes, and their structure is similar to the cell structure in batteries. When eels are stationary they don't generate any electricity, but when they swim they emit from 20 to 50 electric impulses per second. And this discharging energy is precisely what you will hear as you watch these amazing electric eels!

The exceptional African lungfish is certainly worth a look. This species inhabits muddy aquatic basins in tropical Africa. When weather conditions are poor during droughts, the lungfish burrows into the mud and goes into a state of aestivation, or hibernation. This fish is able to do this thanks to its additional lung that originated from a transformation in the swim bladder.

Another surprising subject is representative of amphibians - Ambystoma mexicanum. This species is found only in Mexico in the lake of Chalco and Xochimilco (2300 m). Its characteristic feature is neoteny, which means that during its lifetime it remains in the larval stage, however able to reproduce. As all larvae of amphibians, it has external gills. It has a great ability to regenerate lost body parts, like tail or parts of gills or legs. Especially the juveniles have huge regenerative abilities. This species is protected, inter alia, by CITES.


Another surprising fish living at the border of water and land is Mudskipper. It's an animal with an appearance mor like a frog than a fish. It occurs on the western shores of Africa overgrown with mangrove forests. The Mudskipper is a predatory fish and feeds on insects, worms and small fish. It has eyes like a retractable periscope and well developed pelvic fins, with which they can climb the mangroves.

The dwarf crocodile is probably the most attention-riveting specimen of amphibious reptile at the Gdynia Aquarium. This is the world's smallest crocodile, and it can be found in the wilds of western Africa. Its most unique feature is that its snout is as long as it is wide at its base, which is a characteristic that is not seen in other crocodile species. Its brown eye color is also different from the yellow-green of other crocodile species. This is also one of the few species of crocodiles that includes fruit in its otherwise traditional diet.

 

In addition to all these fascinating creatures, this exhibit is home to the extraordinary Chinese softshell turtle. Although innocent looking enough, this animal is really very dangerous. Similarly to the common snapping turtle, its jaws are strong enough to take off a person's hand! The paludariums are home to many other species including the Common snapping turtle or the Chinese turtle. Not only do these tanks allow you to see all these strange and wonderful creatures, they also provide a glimpse of the plants that are native to various regions of the world.
     
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