Navegando por Assunto "Subterranean biology"

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Texto publicado em jornal
Anophtalmic and epigean?Description of an intriguing new species of Hyalella (Amphipoda, Hyalellidae) from Brazil
(Magnolia Press, 2018) BASTOS-PEREIRA, RAFAELA; OLIVEIRA, MARCUS PAULO ALVES DE; FERREIRA, RODRIGO L.
The absence of eyes in Hyalella (Hyalellidae, Amphipoda) is typical of obligate groundwater-dwelling species. However, a new intriguing blind amphipod of this genus was found in epigean streams from the Iron Quadrangle (state of Minas Gerais, Brazil). Hyalella troglofugia sp nov. presents antenna 1 shorter than antenna 2, gnathopod 1 propodus inner face with four setae, gnathopod 2 propodus posterior margin longer than palm, dactylus slightly longer than palm, pereopod 5 shorter than others and uropod 3 shorter than telson. The absence of eyes and presence of reduced U3 and pereopods of H. troglofugia sp nov. may suggest that such species also inhabits interstitial subterranean spaces. Moreover, the presence of the new species on streams associated to distinct hydrological zones indicates that this species may be present in dif-ferent types of subterranean habitats of the region. We hypothesize that at least part of the population of this species may have left the subterranean environment looking for food and when out of this habitat it preferentially inhabits high water flow stretches of the stream in function of predation avoidance.
Artigo
Do different relevance attributes indicate the same conservation priorities? A case study in caves of southeastern Brazil
(2021-09) Souza, Maysa F. V. R.; Alvarenga, Denizar A.; Souza-Silva, Marconi; Ferreira, Rodrigo L.
In the last decade, the scientific community brought to the debate gaps that slow down the advance of knowledge regarding global biodiversity. More recently, this discussion has reached subterranean environments, where these gaps are even more dramatic due to the relict and vulnerable nature of their species. In this context, we tested ecological metrics related to some of these gaps, checking if the biological relevance of the caves would change depending on ecological attributes related to each metric. The study was carried out in caves from southeastern Brazil, located in a region presenting a high richness of troglobitic species restricted to a narrow geographical extent. Thus, we verified: (a) the cave invertebrate communities’ vulnerability with the Vulnerability Index and the Importance Value for Cave Conservation; (b) the distribution and endemicity of the troglobitic species with the Endemicity Index; (c) the phylogenetic diversity of the troglobitic species considering the average taxonomic distinction (∆+), their richness and evenness. We observed a considerable change in the ordering of the caves’ biological relevance according to each tested attribute (index). We discussed how each of these metrics and their attributes indirectly relate to: (a) the preservation and maintenance of the phylogenetic diversity of subterranean communities; (b) the spatial restrictions of different groups, where the greater their restrictions, the greater their vulnerability; (c) the preservation of caves with high biological relevance considering these different attributes together. Thus, we recommend the use of different metrics so that different ecological attributes can be considered, supporting actions that aim to preserve caves in highly altered regions. Finally, we find that the most biologically important cave in the region is not protected (Gruta da Morena Cave). We warn that this cave needs to be contemplated by a conservation unit in the region urgently.
Artigo
Global distribution of microwhip scorpions (Arachnida: Palpigradi)
(2021-01-29) Mammola, Stefano; Souza, Maysa Fernanda Villela Rezende; Isaia, Marco; Ferreira, Rodrigo Lopes
Aim Historically, research on global distribution patterns has mostly concentrated on conspicuous organisms and thus a large proportion of biodiversity on Earth remains unmapped. We examined the global distribution of palpigrades, a poorly studied group of low dispersive arachnids specialized to subterranean life. We asked what are the ecological factors driving their distributions, and to what extent sampling bias may influence the observed patterns. Location Global. Taxon Palpigrades (Arachnida: Palpigradi) in the genus Eukoenenia. Methods We assembled a database of over 1000 localities and referring to 57 soil- and 69 cave-adapted palpigrades. We tested for differences in range sizes of soil- and cave-adapted species. We used variance partitioning analysis to explore the contribution of climate, nutrient availability and geology in driving observed distributions. Finally, we verified the potential correlation between the number of occurrence records and the number of palpigrades' researchers. Results Europe and Brazil emerged as centres of diversification of cave-adapted palpigrades. Conversely, the diversity of soil-adapted species was distributed over a broader geographical expanse, mainly in the Southern Hemisphere. Both cave and soil species had narrow distribution ranges, with a median value of 0.01 km2; only a few parthenogenetic species were distributed over multiple continents. The distribution of cave- and soil-adapted palpigrades was primarily explained by climatic conditions, and secondarily by nutrient and habitat availability. In the Alps, the distribution of cave-adapted species also bears the signature of historical events related to glaciation cycles. We observed, however, a pronounced people-species correlation, suggesting that the observed patterns are not generalizable to poorly explored areas. Main conclusions Our study highlights enormous gaps in current knowledge about the biogeography of palpigrades. Even if the information is largely incomplete and biased, we show how data can be harnessed to draw a preliminary picture of the global distribution patterns of palpigrades. Thus, we offer a jumping-off point for future studies on the macroecology and conservation of poorly known organisms.
Texto publicado em jornal
Multi-instar descriptions of cave dwelling Erythraeidae (Trombidiformes: Parasitengona) employing an integrative approach
(2021-09) Souza, Maysa F. V. R.; Alvarenga, Denizar A.; Souza-Silva, Marconi; Ferreira, Rodrigo L.
In the last decade, the scientific community brought to the debate gaps that slow down the advance of knowledge regarding global biodiversity. More recently, this discussion has reached subterranean environments, where these gaps are even more dramatic due to the relict and vulnerable nature of their species. In this context, we tested ecological metrics related to some of these gaps, checking if the biological relevance of the caves would change depending on ecological attributes related to each metric. The study was carried out in caves from southeastern Brazil, located in a region presenting a high richness of troglobitic species restricted to a narrow geographical extent. Thus, we verified: (a) the cave invertebrate communities’ vulnerability with the Vulnerability Index and the Importance Value for Cave Conservation; (b) the distribution and endemicity of the troglobitic species with the Endemicity Index; (c) the phylogenetic diversity of the troglobitic species considering the average taxonomic distinction (∆+), their richness and evenness. We observed a considerable change in the ordering of the caves’ biological relevance according to each tested attribute (index). We discussed how each of these metrics and their attributes indirectly relate to: (a) the preservation and maintenance of the phylogenetic diversity of subterranean communities; (b) the spatial restrictions of different groups, where the greater their restrictions, the greater their vulnerability; (c) the preservation of caves with high biological relevance considering these different attributes together. Thus, we recommend the use of different metrics so that different ecological attributes can be considered, supporting actions that aim to preserve caves in highly altered regions. Finally, we find that the most biologically important cave in the region is not protected (Gruta da Morena Cave). We warn that this cave needs to be contemplated by a conservation unit in the region urgently.