Ictio: Amazonian scale fish observations

Ictio records 128,887 valid observations of 121 species/groups of fish, in a total of 81,476 valid fishing events (Figure 1).

Figure 1 – As of June 30, 2025, Ictio has gathered a total of 128,887 valid fish observations in 81,476 lists (fishing events). This information was recorded in 152 (77%) of the 198 level 4 sub-basins of the Amazon.

Currently,  732 citizen scientists and registered organizations have shared information from the 152 level 4 sub-basins (BL4) of the Amazon (i.e., 77%). (More information on the basin classification used by Ictio can be found in Venticinque et al., 2016 – ‘New Geographic Information System (GIS) on rivers and basins for the conservation of aquatic ecosystems in the Amazon’).

The  ‘Madeira – upstream of Jamari’ sub-basin continues to lead in the number of records with 21,797 observations, followed by the ‘São Manoel – upstream Peixoto de Azevedo’ sub-basin (15,676 observations), in the Tapajós River basin, and the ‘Amazon/Solimões sub-basin- between Juruá and Negro’ (14,739 observations) (Figure 2).

Figure 2 – BL4 sub-basins with the most records in Ictio as of June 30, 2025.

Recorded species

Of the 121 species/groups of species recorded in Ictio, the jaraqui (Semaprochilodus insignis) is the most frequently recorded species (8,578 observations), followed by ‘Other fish’ (Fish sp.) with 8,468 observations and the bocachico (Prochilodus nigricans) with 7,581 observations (Figure 3).

Figure 3 – Species/groups of species with the most records in Ictio as of June 30, 2025.

The dorado catfish as a sentinel of Amazon Basin connectivity

The dorado catfish (Brachyplatystoma rousseauxii) makes the longest recorded migration among Amazonian fish, traveling nearly 11,000 kilometers round trip between its spawning areas at the foothills of the Andes and its growth area in the Amazon estuary, already in the Atlantic Ocean. For this reason, the dorado is recognized as an Amazonian icon and a sentinel of connectivity along the entire Amazon River and its main tributaries.

Given its importance, the conservation of the dorado, along with the piramutaba  (Brachyplatystoma vaillantii), another Amazonian catfish that makes  long-distance migrations, is essential for the Amazon Waters Alliance. In this context, the Alliance supports the development of a Regional Plan for the Conservation of Amazonian Catfish, which will be presented at the 15th Conference of the Parties of the Convention on Migratory Species (COP15 CMS) in Brazil in March 2026.

This Plan is being developed jointly with scientists and authorities from the countries where these species are found, who will meet in mid-September to advance its preparation.

Ictio currently records 4,651 dorado observations (Figure 4) and 622 piramutaba or manitoa observations.

Figure 4 –  Map of dorado (Brachyplatystoma rousseauxii)  occurrence or presence according to the records in Ictio.

This note is made possible thanks to the support of the Gordon and Betty Moore Foundation. The content is the responsibility of the Wildlife Conservation Society and does not necessarily reflect the views of the Moore Foundation.