Clearwater part, Rio Orinoco, Venezuela

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Venezuela, Bolivarian Republic of, Anzoátegui, Ciudad Orinoco

The Rio Orinoco, is one of the longest rivers in South America, stretching over 2.000km from its source in the Venezuelan Andes to its mouth in the Atlantic Ocean. The Rio Orinoco is a major waterway that flows through a vast and diverse landscape, providing vital resources for the region’s people and wildlife.

The river is home to a vast diversity of fish species, with estimates ranging from around 400 to over 1.000 species, making it one of the most fish-rich rivers in the world. The exact number of fish species in the river is difficult to determine due to the vastness and complexity of the ecosystem, as well as the ongoing discovery of new species.
Along the banks of the Rio Orinoco, the landscape is characterized by dense forests, savannas, and wetlands. This diverse habitat supports a wide range of wildlife.

Indigenous communities, including the Warao people, have relied on the river’s resources for generations, using it for fishing and more.

Submitted by
Benny Barthel
Approved by
Roberto E. Reis, Pablo C. Lehmann and Flávio Lima
8.1750736, -63.6625252
Geographical region
South America
Drainage Basin
Río Orinoco
River catchment
Llanos area
Water body type
Water body name
Rio Orinoco
Water body part
Flood plain
Water body course
Middle course
Water body: tributary of
Tributary name

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Clear water
Water transparency
Concentration of sediments
Water temperature
26-29 °C
Water flow/curent

Chemical parameters

Dissolved Oxygen

Substrate in nature

Stone form
Submerged terrestrial vegetation

Aquatic Biotope

Date of collecting
Collecting area
River bank
Water depth
Air temperature
28 °C
Full sun


Human settlements
Human settlements
Urban area
Surrounding area

The Orinoco River begins its journey high in the mountains of the Sierra Parima, where it gathers strength from the melting snow and rainfall. It then descends through dense tropical rainforests, carving a path through the rugged terrain of Bolivar. The river’s course is marked by breathtaking waterfalls, including the renowned Angel Falls, the tallest waterfall in the world.

The river’s waters flow through vast stretches of pristine wilderness, offering a sanctuary for an incredible array of plant and animal species. The Orinoco Basin is a biodiversity hotspot, housing countless species of fish, birds, reptiles, and mammals. Jaguars, river dolphins, and giant otters are just a few of the remarkable creatures that call this region home.

Underwater landscape

The underwater landscape of the Rio Orinoco is a hidden world of mesmerizing beauty and remarkable diversity. As the river flows through Bolivar, Venezuela, it carries with it a wealth of life and geological wonders beneath its surface.

Submerging into the depths of the Orinoco reveals a captivating panorama of underwater habitats. The river’s currents create a dynamic environment, shaping various aquatic ecosystems. Sandy riverbanks, submerged forests, and rocky outcrops provide shelter and niches for an abundance of aquatic flora and fauna.

Fish list:

  • Pterophyllum altum (Cichlidae)
  • Crenicichla sp. (Cichlidae)
  • Paracheirodon axelrodi (Characidae)
  • Hypancistrus sp. L201 (Loricariidae)
  • Corydoras habrosus (Callichthyidae)
  • Paracheirodon simulans (Characidae)
Threats to ecology

The ecology of the Rio Orinoco is a marvel of biodiversity and intricate ecological relationships. As one of the largest rivers in South America, it supports a rich array of plant and animal species, contributing to the region’s remarkable natural heritage.

The Orinoco River and its surrounding ecosystems form an intricate web of life. The river’s watershed encompasses a vast range of habitats, including tropical rainforests, wetlands, savannas, and floodplains. Each of these habitats supports unique flora and fauna, adapted to their specific conditions.

Riparian zone

Trees near the aquatic habitat
Many -


  • Independent Publishing - Fishes of the Orinoco in the Wild by Mikolji, I.
    ISBN 1838538836

Comment by the expert

Roberto E. Reis: Description of the location is superficial, little mention to surroundings and no mention to threats to ecology. One photo and link to one commercial video by other author. Six fish species listed out of hundreds, no inverts or plants. Description of the aquatic habitat, riparian zone, and underwater landscape much helped by the video. Bibliography/Sitography weak.

Flávio Lima: The participant used mainy the excellent videos by Oliver Lucanus on aquarium habitats of clearwater rivers from the Orinoco basin.

Pablo C. Lehmann: Excellent graphic material (videos and photos) showing the natural biotope, including correct information on the species present, with accurate comments on the environment and aquatic diversity present. It also includes comments and observations of substrate and other non-abiotic parameters. The video provided only fails to include the scientific names of the species in italics. The research on the aquatic biotope of the Rio Orinoco is informative and generally well-structured. It provides a good understanding of the river’s ecological significance and its diverse aquatic life. It is just not possible to clearly identify threats to the ecology or biotopes of the Orinoco River.