The first thing that catches your attention as you step into our new Americas zone (map here) is the lush greenery – something that may seem out of place in an aquarium. But this is what makes our brand new Central and South American Freshwater Habitat stand out from the other habitats.
As you look down past the waterline, you may wonder why the water is so brown and ‘dirty’.
Truth is, the water is clean. The brown colouration is due to the presence of tannin – an organic compound derived from the brown leaves and driftwood intentionally placed in the habitat. This is to replicate the natural rainforest environment where dead leaves and branches fall into rivers and streams flowing by, thereby making the water brown.
Tannin causes the pH of the water to decrease (more acidic), and ‘softens’ the water as well, due to lower concentration of calcium carbonate. This is characteristic of a blackwater habitat, which is most often found in the rainforests of South America.
The habitat is devided into two sections. On the left, you’ll see our living fossils: the garfish. Among them are the Platinum Alligator Gar (Atractosteus spatula), also called the Snow Whites of our aquarium. These fish are leucistic – a condition in which there is a partial loss of pigmentation which leads to pale skin but does not affect the eyes. This is very different from albinism which is the complete loss of pigmentation, resulting in pale skin and red eyes.
The Platinum Alligator Gars are in stark contrast to the common Alligator Gar (Atractosteus spatula) which are of a dark brown shade. Also sharing this habitat are their close relatives, the Florida Longnose Gar (Lepisosteus osseus) and the Spotted Gar (Lepisosteus oculatus). Compared to the Alligator Gars, these two species are smaller, have shorter snouts with long pointed teeth, and ganoid scales (typical of gars) which form an interlocking protective armour akin to medieval chainmail.
Over on the right side of this freshwater habitat, you’ll see a snapshot of an Amazon River habitat. The Amazon River in South America is the largest river in the world by amount of water discharged into the sea per second. It is also the world’s longest, running through Brazil, Peru and Columbia.
The Amazon River is home to more than 5,600 species of fish. In our very own South American River habitat, we have two types of unique circular shaped cichlids that are extremely social in nature – Heckel Discus (Symphysodon discus) and Brown Discus (Symphysodon aequifaciatus).
They form groups consisting of dozens of individuals, but once a pair starts to breed, they move away from the group to protect their young from cannibalism by the other adults. The parents begin to produce a large amount of mucus on their bodies to feed their babies, taking turns to provide food for their fry.
Sharing the habitat with them are the graceful Altum Angelfish (Pterophyllum altum) and Santa Isabella Angelfish (Pterophyllum scalare variant), which contrast starkly with the discus’ circular shape.
Before the angelfish begin to breed, they carry out a head dance as part of their courtship behaviour. Once the pair has been established, they choose a flat surface and clean it for around 24 hours before laying their eggs on it. Spawning may take up to 2 hours, during which the female will lay her eggs on the cleaned surface, with the male behind her, brushing the eggs to fertilise them. Angelfish are very dedicated parents who will defend their fertilised eggs aggressively until the babies have hatched.
Also part of the Americas zone is the Poison Arrow Frogs habitat which is just two steps away.
Here, you’ll find the tiniest and most lethal residents of our aquarium. These Poison Arrow Frogs sport bright, colourful and eye-catching patterns that serve as a warning to any potential predators that they are poisonous.
In their native habitat, they consume spiders, ants and millipedes that contain chemical compounds known as alkaloids. These alkaloids are used by the frogs to produce the poison that they then secrete onto their colourful skin! However under human care, they are fed wingless fruit flies and crickets that do not contain alkaloids, and as such they do not produce toxins.
When you’re at the Central and South American Freshwater Habitat, do spend some time to take in the sights and sounds of this immersive zone. Just close your eyes and listen to the trickling of running water and chirping of birds, and you will feel as if you’re in the heart of the tropical rainforest!