''Phreatobius sanguijuela'' is a South American

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of heptapterid catfish that lives in underground waters. This species was first discovered in a hand-dug well located within the Paragúa River drainage, a tributary of the Guaporé (Iténez) River in

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

. Later it was discovered just across the border in several wells near

São Francisco do Guaporé São Francisco do Guaporé is a municipality located in the Brazilian state of Rondônia. Its population was 20,681 (2020) and its area is 10,960 km². The municipality contains 9% of the Serra dos Reis State Park. It contains 86% of the ...

in the

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

ian state of

Rondônia Rondônia () is one of the 26 states of Brazil, located in the northern subdivision of the country (central-western part). To the west is a short border with the state of Acre, to the north is the state of Amazonas, in the east is Mato Grosso, ...

. This species is threatened by

environmental degradation Environmental degradation is the deterioration of the environment (biophysical), environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; an ...

due to

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

, water extraction for drinking and

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...

, mineral extraction, and associated erosion. It is often killed when accidentally caught from wells because of a superficial resemblance to

leech Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodie ...

es. This small fish reaches a maximum

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of . ''P. sanguijuela'' differs from '' P. cisternarum'' in a number of ways, but the main differences are the absence of eyes (which are present in ''P. cisternarum'').

References

Catfish of South America Fish described in 2007 Cave fish Fish of Bolivia Freshwater fish of Brazil Heptapteridae {{catfish-stub