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Rio Nanay, Loreto, Peru

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Peru, Loreto, Iquitos

 

Rio Nanay is a Peruvian river in the Loreto region of northeastern Peru. It is 315km long and is a tributary of the Amazon River, with an area of 17.600km². The Nanay River is a slow-moving river that traverses flat, low-lying land, having a winding course that forms dense marshes and lagoons, and abundant fish resources, including many species of well-known ornamental fish. It is 3.5km from Iquitos, the largest town in the Peruvian Amazon.

The Nanay is a black water river stained by the tannins of the surrounding secondary forests, with trees such as ceticos, cataguas and chontas lining its banks. During the rainy season, the river overflows its banks, flooding the nearby forest, causing these trees to collapse and fall into the water. This tangle of fallen branches and roots creates a habitat for a large number of smaller fish. The soil is sandy, white in color and there are no stones.

Submitted by
Emil Visan
Approved by
Roberto E. Reis, Pablo C. Lehmann and Flávio Lima
GPS
-3.9123828, -73.6625290
Geographical region
South America
Drainage Basin
Rio Amazonas
River catchment
Nanay Rio
Water body type
Rio
Water body name
Nanay
Water body part
Meander
Water body course
Middle course
Water body: tributary of
Rio
Tributary name
Amazonas

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Black water
Water transparency
Medium
Concentration of sediments
Medium
Water temperature
26-28 °C
Water flow/curent
Slow

Chemical parameters

pH
6.0
Conductivity
25
GH
KH
Dissolved Oxygen

Substrate in nature

Sand
White
Pebble/Gravel
None
Stone
None
Stone form
Silt/Mud
Reddish
Leaves
Many
Driftwood
Many
Submerged terrestrial vegetation
Yes

Aquatic Biotope

Date of collecting
Collecting area
Water depth
Air temperature
Sunlight

Environment

Surrounding area

The rainy season starts in September/October, which causes an increase in water level, then it falls again in May/June. There are no conventional seasons (Spring, Summer, Autumn, Winter). In other words, the river determines the season.

During the rainy season, the river overflows its banks, flooding the nearby forest, causing these trees to collapse and fall into the water. This tangle of fallen branches and roots creates a habitat for a large number of smaller fish. The soil is sandy, white in color and there are no stones.

Underwater landscape

Vegetation in the river is negligible, more variety of plants can be met in the oxbow, where the river current is low or not at all. Plants that we can meet there are Pontederia crassipes, Pistia stratiotes, Hydrocotyle leucocephala and various species of Echinodorus parviflorus, Echinodorus orizontalis, Echinodorus grisebachii.

The sandy bed is covered with leaves and dead wood. The edges are thickly overgrown with the roots of coastal trees and are ideal for small fish such Apistogramma, Corydoras, Pterophyllum scalare, Symphysodon aequifasciatus and many species of Characidae.

Fish:

  • Acestrorhynchus falcirostris (Acestrorhynchidae)
  • Acestrorhynchus microlepis (Acestrorhynchidae)
  • Brycon pesu (Bryconidae)
  • Chalceus erythrurus (Chalceidae)
  • Chalceus macrolepidotus (Chalceidae)
  • Characidium fasciatum (Crenuchidae)
  • Charax gibbosus (Characidae)
  • Hemigrammus unilineatus (Characidae)
  • Hemigrammus ocellifer (Characidae)
  • Hyphessobrycon bentosi (Characidae)
  • Hemigrammus pulcher (Characidae)
  • Hyphessobrycon erytrostigma (Characidae)
  • Hyphessobrycon serpae (Characidae)
  • Hyphessobrycon loretoensis (Characidae)
  • Metynnis hypsauchen (Serrasalmidae)
  • Moenkhausia oligolepis (Characidae)
  • Myleus rubripinnis (Serrasalmidae)
  • Myleus schomburgki (Serrasalmidae)
  • Mylossoma duriventris (Serrasalmidae)
  • Mylossoma aureum (Serrasalmidae)
  • Petitella georgiae (Characidae)
  • Serrasalmus rhombeus (Mylossoma aureum)
  • Triportheus elongatus (Triportheidae)
  • Triportheus albus (Triportheidae)
  • Carnegiella schereri (Gasteropelecidae)
  • Carnegiella strigata (Gasteropelecidae)
  • Gasteropelecus sternicla (Gasteropelecidae)
  • Apistogramma bitaeniata (Cichlidae)
  • Apistogramma cacatuoides (Cichlidae)
  • Aequidens tetramerus (Cichlidae)
  • Biotodoma cupido (Cichlidae)
  • Cichla monoculus (Cichlidae)
  • Cichlasoma amazonarum (Cichlidae)
  • Crenicichla anthrurus (Cichlidae)
  • Crenicara puntulatum (Cichlidae)
  • Heros severum (Cichlidae)
  • Mesonauta festivus (Cichlidae)
  • Pterophyllum scalare (Cichlidae)
  • Satanoperca jurupari (Cichlidae)
  • Corydoras sychri (Callichthyidae)
  • Dianema longibarbis (Callichthyidae)
  • Corydoras agassizi (Callichthyidae)

Aquatic vegetation:

  • Echinodorus parviflorus (Alismataceae)
  • Echinodorus horizontalis (Alismataceae)
  • Echinodorus grisebachii (Alismataceae)
  • Salvinia natans (Salviniaceae)
  • Pontederia crassipes (Pontederiaceae)
  • Pistia stratiotes (Araceae)
  • Hydrocotyle leucocephala (Araliaceae)

In the meanders in the lit riparian places, many plants from the Cyperus family grow, among them Cyperus giganteus (Giant papyrus).

Threats to ecology

Deforestation of land for palm plantations and pollution from human activities on the land, such as the use of fertilizers and herbicides.