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Scientific expedition in isolated Amazon region revealed a new genus of freshwater crab found in high-altitude forest on Pico da Neblina. Rare record reinforces the importance of environmental preservation and the role of the Yanomami in protecting species still unknown to science.
Researchers identified a new genus and a new species of freshwater crab in Pico da Neblina National Park, Amazonas, after a scientific expedition conducted in 2022 in the Serra do Imeri, one of the most isolated and preserved areas of the Brazilian Amazon.
Named Okothelphusa trefauti, the crustacean was located at approximately 1,730 meters of altitude, in a stream surrounded by high-altitude forest, an environment considered strategic for research on rare species and evolutionary processes still little known.
During the collection of biological material, researchers linked to the Museum of Zoology of the University of São Paulo found only three specimens of the animal, one male and two females, a scenario that highlights the rarity of the species and the difficulty of access to the region.
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With approximately 2.3 million hectares, Pico da Neblina National Park overlaps with the Yanomami Indigenous Land and is managed by the Chico Mendes Institute for Biodiversity Conservation, ICMBio, in partnership with the indigenous peoples who live in the region.
New genus of crab found in high-altitude forest
The denomination of the new genus combines “Oko”, a word related to crab in the Yanomami language, with the term “thelphusa”, used in the scientific classification of freshwater crabs found in different mountainous regions of South America.
While the genus refers to the indigenous language, the species name honors the herpetologist Miguel Trefaut Rodrigues, responsible for leading the scientific expedition that explored difficult-to-access areas within the Serra do Imeri.
In addition to expanding the catalog of Brazilian fauna, the research described an unprecedented genus of the family Pseudothelphusidae, a group known for bringing together freshwater crabs adapted to humid and mountainous environments spread across the South American continent.
The description was published in the scientific journal Zootaxa, in an article signed by Marcos Tavares and Célio Magalhães.
The analysis of the material showed distinct morphological characteristics in relation to other known crabs.
The male specimen was decisive for identification, because male reproductive structures help specialists differentiate species and genera in this group of crustaceans.
Before confirmation, researchers evaluated the possibility of the animal belonging to the genus Microthelphusa, used in similar classifications.
Further studies, however, indicated its own lineage, which led to the creation of Okothelphusa and the revision of related species described in Venezuelan territory.
Pico da Neblina’s biodiversity still challenges science
Among mountains covered by forest and areas of extremely restricted access, the region where the crab was found is among the least scientifically explored territories in the entire Brazilian Amazon.
While isolation makes expeditions difficult, it also favors the emergence of species with very limited distribution, especially on mountain tops, high-altitude forests, and streams separated by natural barriers.
According to the park chief, Cassiano Gatto, local biodiversity is still far from being fully known.
“We still don’t know all the existing biodiversity.
Each new expedition discovers new and unique life forms and, due to the large size of the park, we believe we will find much more,” he stated.
In the higher areas of the unit, the proportion of plants and animals that do not occur anywhere else on the planet can reach 30% of the total species, according to the park management’s assessment.
Poorly fertile soils, intense variations in humidity, and extreme temperatures help shape this particular fauna and flora.
This set of conditions also makes the environment more vulnerable.
Species that live in restricted areas, with low dispersal capacity, tend to suffer more from climate change, habitat degradation, and external pressures, because they do not easily find other suitable places to survive.
Rare species has terrestrial habits and low dispersal
With predominantly terrestrial habits, the Okothelphusa trefauti lives in humid areas near watercourses, moving through waterlogged environments that offer favorable conditions for feeding and reproduction.
As with other members of the Pseudothelphusidae family, the species does not have a free larval stage, a characteristic that reduces its dispersal capacity and increases the chances of isolated populations developing.
This direct development helps explain why similar species can be restricted to small areas, sometimes limited to a single mountain range or mountain.
In regions like the Serra do Imeri, this pattern makes every new scientific survey relevant for understanding the evolutionary history of Amazonian fauna.
The discovery occurred while researchers were collecting tadpoles, which shows how expeditions focused on one group of animals can reveal organisms from other, still unknown groups.
In remote areas, this type of finding usually depends on authorizations, complex logistics, and dialogue with local communities.
Yanomami knowledge helps preserve the Amazon
Within the Pico da Neblina National Park, ICMBio advocates for the integration of scientific research and traditional Yanomami knowledge as a strategy to expand biodiversity monitoring in still little-studied areas.
In addition to direct participation in activities carried out in the territory, indigenous people also collaborate with information on natural cycles, movements, and traditional use of resources present in the forest.
For the Yanomami, the forest is called Urihi, an expression associated with the mother-forest.
This way of understanding the territory brings together knowledge about natural cycles, species, movements, and resource management, elements that can strengthen conservation actions when articulated respectfully with science.
Cassiano Gatto states that the park still has little-studied areas, such as the high-altitude forests.
According to him, the participation of Yanomami partners will be important to record fauna and flora in the coming years and expand monitoring capacity in an extensive and restricted-access region.
Illegal mining and climate change threaten protected region
Despite its ecological relevance, the conservation unit faces threats associated with illegal mining and rising temperatures.
These factors increase the risk to sensitive environments formed over thousands of years and to species that have not yet been fully described by science.
The identification of Okothelphusa trefauti reinforces the role of Pico da Neblina National Park as a strategic area for research, conservation, and territorial protection.
The record also highlights the importance of joint action between ICMBio, researchers, and the Yanomami people in preserving a still partially unknown Amazonian biodiversity.
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