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Ameca River, Jalisco, Mexico

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Mexico, Jalisco, Jalisco

The Río Ameca had one of the most extraordinary fish faunas in the past, but unfortunately human weakness has sealed their fate. Although fish of various species still live there such as Banded allotoca, Ameca chub, Amatlan chub, there are also a few that have become extinct in their natural habitat, like for example Golden skiffia, Notropis amecae.

The river runs for some 230km in the west of Mexico, 23km from the capital, before flowing into the Bahia de Banderas on its way to the Pacific Ocean. There are a few trees along the banks, but it cannot be said that there are many driftwood in the river.

The substrate is mostly composed of fine sand, rounded gravel and pebbles. It is also home to many algae, which are a favourite food for the organisms that live in it.

Nowadays, people don’t take enough care of this beautiful place, unfortunately – you can see rubbish dumps in many places along the river banks.

Submitted by
Anikó Csanadi
Approved by
Juan M. Artigas Azas, Jairo Arroyave & Michael Köck
GPS
20.5822334, -103.8488846
Geographical region
Central America
Drainage Basin
Ameca River basin
River catchment
Bahía de Banderas
Water body type
River
Water body name
Ameca River
Water body part
Flood plain
Water body course
Middle course
Water body: tributary of
River
Tributary name
Ahuacatlán, Amatlán de Canas

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Clear water
Water transparency
Medium
Concentration of sediments
Medium
Water temperature
24 °C
Water flow/curent
Slow

Chemical parameters

pH
7.5
Conductivity
GH
18 mg/l
KH
18 mg/l
Dissolved Oxygen
80 %

Substrate in nature

Sand
Beige
Pebble/Gravel
Mixed
Stone
Mixed
Stone form
Roundish
Silt/Mud
Beige
Leaves
Few
Driftwood
Few
Submerged terrestrial vegetation
Yes

Aquatic Biotope

Date of collecting
Collecting area
Water depth
Air temperature
Sunlight

Environment

Environment
Affected by human activity
Affected by human activity
Agriculture
Agriculture
Massive
Surrounding area

The Ameca River is one of the most important rivers in Mexico. Both in agricultural and industrial terms, as well as for Nature conservation.

The higher areas are characterised by oak and pine trees, while the lower areas are a tropical dry broadleaf forest ecoregion. The northern and north-western parts are grasslands. The mangrove areas are home to a rich fauna, including crocodiles, wild boar, herons, gulls, kingfishers and green turtles. It is one of the most popular birdwatching sites.

Jalisco is home to 25% of the total plant population of Mexico. In warm climates it is mostly moss, orchids, citrus and cedar species, in temperate climates pines, ferns and birches, and in semi-arid climates grasses and willows.

Underwater landscape

The longest stretch of the river is dominated by seaweeds and grasses, such as Ceratophyllum species and Juncus species.

The river bed is largely composed of fine sand, rounded gravel and pebbles. There are very few trees along the banks of some of the scasses, so there is not much driftwood. In some places, the riverbed is covered with algae, which provides food for the fish and turtles that live there.

The river had a very diverse fish fauna, but unfortunately poor environmental regulations and human pollution have led to the extinction of many species.

Fishlist:

  • Ameca splendens (Goodeidae)
  • Allotoca goslinei (Goodeidae)
  • Algansea amecae (Cyprinidae)
  • Yuriria amatlana (Cyprinidae)
  • Notropis amecae (Cyprinidae)

Aquatic plants:

  • Najas guadalupensis (Hydrocharitaceae)
  • Ceratophyllum demersum (Ceratophyllaceae)
  • Pistia stratiotes (Araceae)
  • Pontederia crassipes (Pontederiaceae)
Threats to ecology

Unfortunately, the area around the river is very polluted and very close to many towns. Obviously, the river is also used by industry (for example silver mining) and agriculture.

More and more animal and plant species are being protected, but for some it is too late (Tequila splitfin, Finescale splitfin, Golden skiffia, Ameca shiner).

Fortunately, conservation organisations are joining the rescue and conservation effort and it is possible that in the future more species that were previously thought to be extinct will be reintroduced to their natural habitat.

This work is being carried out by enthusiastic aquarists,too, who are passionate about conservation and preserving these precious creatures for future generations, be they birds, mammals, amphibians or fish.

Riparian zone

Trees near the aquatic habitat
- Astronium graveolens (Anacardiaceae)
Trees near the aquatic habitat
- Swietenia humilis (Meliaceae)
Trees near the aquatic habitat
- Quercus subg. Quercus (Fagaceae)

Comment by the expert

Michael Köck: The Ameca river is composed of different affluents and stretches and many of the areas do not match the description. Additionally the fish list is rather incomplete and mentions an extinct in the wild species as extant. The Bibliography and Sitography is poor.

Juan M. Artigas Azas: The description covers generally the whole basin of the Ameca River and less specifically the areas where this species has inhabited, which are the headwaters of the river around the town of Teuchitlán. The list of species given stays short, with the information available. It is correct that the species is listed as Extinct in the Wild, so you may find encouraging to know that a small population of 40 specimens was reintroduced in the upper spring at El Rincon swimming place in Teuchitlán by biologist at the UMSNH (Universidad Michoacana de San Nicolás de Hidalgo at Morelia). I was able to photograph them in November 2018 (mexfish.info), in January of this year I could testify that they were still present in the small spring.

Jairo Arroyave: As pointed out by Michael, the fish list is incomplete, and the threats and description seem to be for the entire basin and not for the actual biotope locality. Also, being a long river, biotopes are going to be very variable and different depending on the section. That is barely discussed anywhere in the description of the BIN. Not clear which section of the basin the BIN is from. Also, there is a description of underwater landscape but no photos or video, at least that I could find. Only video of a flooding event from a car, not clear where from exactly. Very sparse bibliography.