Riverbank area of the Río el Subin, Petèn, Guatemala

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Guatemala, Sayaxché, El Petén

Río El Subín is a stream in Guatemala. Río El Subín is situated north of Laguneta Mangal, and east of Laguneta El Casco. El Subín is a small river near Sayaxché in the Rio Usumacinta drainage. Río el Subín flows from northwest to southeast, and along it there are several small tributaries that have their outlet in it. El Subín flows approximately 76 km, and ends up in the larger Río de la Pasion.

This area is also very biologically diverse, and holds an abundance of plants, fish and birds. Río el Subín is mostly jungle with some open clearings. Some areas around the Sayaxché region have been cut down, but the upstream areas of Subín is still relatively intact.

Submitted by
David Nørholm
Approved by
Juan M. A. Azas & Jairo Arroyave
16.6368752, -90.1828613
Geographical region
Central America
Drainage Basin
Rio Usumacinta
River catchment
Rio de la Pasion
Water body type
Water body name
Rio El Subìn
Water body part
Water body course
Middle course
Water body: tributary of
Tributary name
Rio de la Pasion

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Clear water
Water transparency
Concentration of sediments
Water temperature
25 °C
Water flow/curent

Chemical parameters

Dissolved Oxygen
80 %

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


Affected by human activity
Affected by human activity
Surrounding area

The River flows through both jungle and open grassy areas. Río El Subín has a lot of human traffic and is used, for example, for both bathing and washing cloth. There are connecting faster flowing shallow rocky riffles which connect to pools which can be as deep as 4 meters. These pools can also contain lots of wood and the substrate is generally silted.

River width varies from 40 meters to only 5 meters. There are lots of aquatic plants near the river bank such as Myriophyllum and columns of Vallisneria, and also terrestrial overhanging grasses and trees. There can be quite dense plantation close to the riverbank in the jungle like areas.

In the wet season some trees can even be flooded by the river.

Underwater landscape

The Río el Subín is not the typical Central American river, since there’s actually some aquatic vegetation, although it might be sporadic in certain areas. Besides the aquatic plants El Subín seems like the typical river of the area with lots of round river rocks, fallen logs, driftwood, branches, roots and leaf litter. The Substrate is a mixture of sand silt with areas of leaf litter, especially through tree lined parts of the river. Along the tree lined river bank there is submerged driftwood and Xiphophorus alvarez lots of leaf litter.


  • Chuco intermedium
  • Thorichthys meeki
  • Petenia splendida
  • Oscura heterospila
  • Rheoheros lentiginosus
  • Thorichthys helleri
  • Trichromis salvini
  • Vieja melanurus
  • Thorichthys pasionis
  • Astyanax aeneus
  • Xiphophorus alvarez
  • Carlhubbsia stuarti
  • Belonesox belizanus
  • Xiphophorus signum
  • Gambusia luma
  • Gambusia sexradiata
  • Pseudoxiphophorus attenuatus
  • Poecilia mexicana

Aquatic plants:

  • Myriophyllum sp.
  • Nymphaea sp.
  • Ceratophyllum demersum
  • Vallisneria sp.
  • Hydrocharis laevigata
Threats to ecology

The Rio El Subín, and the area around the river, is threatened by human activity. The river has been used for bathing and washing of cloth in many years, which has both disturbed and harmed the flora and fauna along the river.

Agriculture is also located in the area, and in some places farm animals even live all the way down to the banks of the river. There is also industrial areas close to the river and deforestation is also a factor.

All this together gives the impression of a river challenged and threatened by human activity.

Riparian zone

Trees near the aquatic habitat
Many -

Comment by the expert

Juan M. A. Azas: Lovely, I have been at Rio Subin several times, and the description is accurate, I however found more silt than mentioned, a little warmer and deeper. But this could be dependent on the season. The variety of fish in Rio Subin is astounding, as the list shows However, I found Hyphessobrycon compressus and Phallichthys fairweatheri are missing from the list, although a few of the species mentioned in the list I have not seen there. The river has dried out several times in the past so the environment may be constantly changing.

Jairo Arroyave: Research on this aspect seems sufficient and satisfactory; the list of fish species appears thorough, as well as that for aquatic plants. Not sure if the video documenting the BIN is by the author or by a third party. The video seems to focus on one particular species and fails to document the entirerty of the biotope, including other species of fish. Besides Thorichthys pasionis I could barely see a species of Astyanax but no other fish species. Description of physicochemical parameters seems adequate. Use of bibliography also seems sufficient.