Aquatic biota of different karst habitats in epigean and subterranean systems of Central Brazil – visibility versus relevance of taxa

Abstract

Citation: Simões LB, dos Santos Ferreira TC, Bichuette ME (2013) Aquatic biota of different karst habitats in epigean and subterranean systems of Central Brazil -visibility versus relevance of taxa. Subterranean Biology 11: 55-74. doi:10.3897/subtbiol.11.5981 AbstractThe karstic area of São Domingos, central Brazil, holds extensive drainage systems. In order to understand its biodiversity, various volumes of water were filtered with planktonic nets in stretches of subterranean and superficial rivers on five different occasions. We sampled four drips (152L), three calcite pools (368L), two subterranean rivers fed mainly by percolation water (6,395L), two subterranean rivers fed mainly by water coming from a sinkhole (4,175L) along different caves, one resurgence (158L), and four epigean rivers (101,690L). Physical and chemical variables were measured at some sites. Canonical Correlation Analysis was used to verify relationships between taxa and environment. The degree of similarity of the biota was assessed by cluster analysis (Sorensen, single linkage). There were records of exclusive taxa in epigean and subterranean samples, mainly in drips, which harbour the most unique fauna. The high richness of taxa presently recorded reveals the potential of the vadose zone biota in the tropical region, which was neglected in studies on Brazilian subterranean biodiversity. According to our results, the unsaturated zone tropical fauna may have different composition compared to that from temperate habitats. The studied communities were dominated by rotifers, while crustacean are predominant in the latter. The hypothesis can be clarified with the increase of long term studies and taxa identification at species level, besides the use of complementary sampling methods.

Richness and taxonomic distinctness of cave invertebrates from the northeastern state of Goiás, central Brazil: a vulnerable and singular area

“…São Domingos possess complex systems of surficial and subterranean drainage, with high potential of organic matter carriage and accumulation of debris in some caves. Based upon this, these caves present high richness of subterranean fauna, whether terrestrial or aquatic (Pinto-da-Rocha 1995, Rheims and Pelegatti-Franco 2003, Majer et al 2003, Simões et al 2013. Seven troglobitic species of fishes have been recorded so far, configuring a high diversity for this group (Bichuette 2003, Bichuette andTrajano 2003).…”

Dark diversity in the dark: a new approach to subterranean conservation

“…The region is within the Morphoclimatic Domain of Cerrado (Ab'Saber 1977), predominantly with cerrado, and under tropical seasonal climate, with wet summers and dry winters (Köppen's "AW") (Alvares et al 2014). A solid body of knowledge has been built about subterranean fauna from São Domingos, because the region is explored since the onset of biospeleology in Brazil, in the early eighties (Dessen et al 1980;Trajano and Gnaspini-Netto 1991, Pinto-da-Rocha 1995, Simões et al 2013Bichuette et al 2019). Most published faunistic lists of subterranean fauna suffer from difficulties related to taxonomic identification and description of species (Trajano and Bichuette 2010), which prevented us from calibrating the species pool using previously published faunal lists.…”

“…Even though São Domingos is protected by the boundaries of a State Conservation Unit (Terra Ronca State Park -PETER), the integrity of subterranean environments is still at risk because portions of the headwaters of all subterranean rivers are unprotected or in close proximity to anthropogenic threats, such as soybean plantations and pastures. Therefore, the area is still affected by land ownership problems and by anthropic activities outside the park resulting in sedimentation and groundwater pollution (Simões et al 2013).…”

An important site for conservation of bats in Brazil: Passa Três cave, São Domingos karst area, with an updated checklist for Distrito Federal (DF) and Goiás state

“…of 17,000 recorded caves (CECAV 2018) and a potential to 100,000 according to Auler et al (2001), and most of this heritage is under threat by mining and other huge economic purposes, such as hydro electrical projects. The São Domingos karst area, Goiás state, central Brazil, is characterized by the presence of huge cave systems crossed by allochthonous streams, with large amounts of organic matter available for cave organisms, supporting rich aquatic and terrestrial communities (e.g., Bichuette and Trajano 2003, Simões et al 2013, Bichuette et al 2015. It is the second most intensively surveyed Brazilian karst area after the Alto Ribeira, but so far no comprehensive study on the bat communities from these caves has been undertaken.…”