The rivers (Rios) Sucuri, Bonito and Da Prata are among the clearest freshwater habitats in the world. No other place, except perhaps Africa’s Lake Malawi, offers such an incredible opportunity to observe our aquarium fish in their natural habitat. The Brazilian government has long recognized the unique region, and today many of the most striking natural wonders are protected areas or national parks.
The amazing water clarity is easily explained because the river originates from artesian wells and literally springs out of the ground. The water is so clear there that the the entire pool (which is more than 60 feet long) is visible under water. The pool is home to a small number of juveniles of the larger species of fish and some impressive schools of the smaller tetras. The shallow, clear water allows for a lush growth of plants of many species, particularly fantastic forests of Amazon sword plants (Echinodorus).
Brycon Hilari. Youtube
A Río Sucuri habitat tank with some rocks, small pieces of driftwood and many aquatic plants is relatively easy to recreate. It can include schools of the common serpae tetra (Hyphessobrycon callistus
The Real Deal
Within the natural habitats of this river, the popular serpae tetra is the most striking species in the shallows. The bright sun makes its intense red color visible, even from a great distance. The small tetras closely follow the larger, peaceful characins as they forage for food in the substrate. These larger characins include pacu (Collossoma macropomum), Leporinus frederici, Curimata curimata and Leporellus vittatus. Schools of up to several hundred smaller tetras will follow these larger gentle fish around to feed on the small crustaceans and other matter stirred up as they dig in the substrate. Smaller individuals of the large predators crowd the shallows, hunting the smaller fish, shrimp and small worms in the leaf litter.
The main channel is safe only for the largest fish. The large predators ensure that few fish less than 1 foot in length can be seen here. The largest, fastest fish is the dorado (Salminus maxillosus). At more than 40 inches, the largest individuals are, without doubt, the kings of this domain. At the surface, schools of Brycon hilari crowd to feed on insects and the fallen fruits and leaves of the trees above. Small troops of black pacu and Leporinus frederici are too large to be threatened by the predators, so they spend their time feeding off of aquatic plants and tree branches whose leaves touch the surface.
Aquarists cannot completely mimic the río Sucuri in a biotope aquarium; there is no way we could track down many of the aquatic plant species found there or adequately care for large fish such as the pacu and the dorado. We can bring a small slice of this Brazillian wonder into our homes by recreating parts of this South American habitat. Our home aquariums are suitable for smaller South American fish and several species of plants that are sold at our local fish stores. The río Sucuri — with its cool, clear water, abundant plants and dazzling fish — is a great source of inspiration when creating a lifelike biotope for our farm-raised aquarium fish.
Residents of Río Sucuri
- Curimata curimata
- Brycon hilari
- Leporinus frederici
- Tiger shovelnose (Pseudoplatysoma tigrinum)
- Black pacu (Collosoma macropomum)
- Dorado (Salminus maxillosus)
- Swamp eel (Symbranchus marmoratus)
- Crenicichla vittata
- Pike cichlid (Crenicichla aff. lepidota)
- Leporellus vittatus
- Leporinus striatus
- Cochliodon species
- Hypostomus species
- Barracuda (Acesterohynchus species)
- Darter tetra (Characidium fasciatum)
- Astyanax bimaculatus
- Hyphessobrycon sp.
- Serpae tetra (H. callistus)
- Hemigrammus species
- Apeirodon affinis
- Bristlenose catfish (Ancistrus dolichopterus)
- Aphyocharax paraguayensis
- Cichlasoma bimaculatum
Water in the Rio Sucuri is medium hard, and has a neutral or slightly alkaline pH. The river comes from artesian wells, literally springing out of the ground.