Adalberto J. Santos

Delimiting Areas of Endemism through Kernel Interpolation

We propose a new approach for identification of areas of endemism, the Geographical Interpolation of Endemism (GIE), based on kernel spatial interpolation. This method differs from others in being independent of grid cells. This new approach is based on estimating the overlap between the distribution of species through a kernel interpolation of centroids of species distribution and areas of influence defined from the distance between the centroid and the farthest point of occurrence of each species. We used this method to delimit areas of endemism of spiders from Brazil. To assess the effectiveness of GIE, we analyzed the same data using Parsimony Analysis of Endemism and NDM and compared the areas identified through each method. The analyses using GIE identified 101 areas of endemism of spiders in Brazil GIE demonstrated to be effective in identifying areas of endemism in multiple scales, with fuzzy edges and supported by more synendemic species than in the other methods. The areas of endemism identified with GIE were generally congruent with those identified for other taxonomic groups, suggesting that common processes can be responsible for the origin and maintenance of these biogeographic units.

Strong spatial structure, Pliocene diversification and cryptic diversity in the Neotropical dry forest spider Sicarius cariri

The Brazilian Caatinga is part of the seasonally dry tropical forests, a vegetation type disjunctly distributed throughout the Neotropics. It has been suggested that during Pleistocene glacial periods, these dry forests had a continuous distribution, so that these climatic shifts may have acted as important driving forces of the Caatinga biota diversification. To address how these events affected the distribution of a dry forest species, we chose Sicarius cariri, a spider endemic to the Caatinga, as a model. We studied the phylogeography of one mitochondrial and one nuclear gene and reconstructed the paleodistribution of the species using modelling algorithms. We found two allopatric and deeply divergent clades within S. cariri, suggesting that this species as currently recognized might consist of more than one independently evolving lineage. Sicarius cariri populations are highly structured, with low haplotype sharing among localities, high fixation index and isolation by distance. Models of paleodistribution, Bayesian reconstructions and coalescent simulations suggest that this species experienced a reduction in its population size during glacial periods, rather than the expansion expected by previous hypotheses on the paleodistribution of dry forest taxa. In addition to that, major splits of intraspecific lineages of S. cariri took place in the Pliocene. Taken together, these results indicate S. cariri has a complex diversification history dating back to the Tertiary, suggesting the history of dry forest taxa may be significantly older than previously thought.

A revision of the Neotropical species of the lynx spider genus Peucetia Thorell 1869 (Araneae: Oxyopidae)

The spider genus Peucetia includes 54 species of medium-sized and widely distributed spiders. The majority of its species occurs in the tropical regions, of which only the African fauna has been recently revised. In the Neotropical Region 26 species were described, of which 17 are here synonymyzed. Peucetia tranquillini Mello-Leitao 1922, P. rubrigastra Mello-Leitao 1929, P. meridionalis Mello-Leitao 1929, P. villosa Mello-Leitao 1929, and P. viridisternis Mello-Leitao 1945 are considered junior synonyms of P. flava Keyserling 1877. Eight names, Peucetia similis Keyserling 1877, P. amazonica Mello-Leitao 1929, P. heterochroma Mello-Leitao 1929, P. maculipedes Piza 1938, P. trivittata Mello-Leitao 1940, P. duplovittata Mello-Leitao 1941, and P. roseonigra Mello-Leitao 1943 and Tapinillus argentinus Mello-Leitao 1941 are considered junior synonyms of P. rubrolineata Keyserling 1877. Both senior species are extremelly common, occurring from Colombia to northern Argentina. Peucetia macroglossa Mello-Leitao 1929, recorded only from Central Brazilian Amazonia and Guyana is considered a senior synonym of P. melloleitaoi Caporiacco 1947. Two species occur from Southern USA to northern Colombia: Peucetia viridans (Hentz 1832) and P. longipalpis F. O. P.-Cambridge 1902. The former is recognized as a senior synonym of P. poeyi (Lucas 1857), P. bibranchiata F. O. P.- 1902 and P. rubricapilla Petrunkevitch 1925 and the later as a senior synonym of P. cauca Lourenco 1990. Peucetia viridis (Blackwall 1858), known from Africa, southern Spain and Middle East is newly recorded from the West Indies. One new species, Peucetia cayapa sp. n., is described and illustrated based on males and females from Ecuador and Peru. Peucetia caldensis Garcia-Neto 1989, from Brazil, is transferred to Tapinillus Simon 1898. The type specimens of three species, P. quadrilineata Simon 1891 and P. thalassina (C. L. Koch 1847) from Central America, and P. smaragdina Mello-Leitao 1941 from Colombia are probably lost. Since their original descriptions are not sufficiently clear for their recognition, they are considered nomina dubia.

Biodiversity conservation gaps in the Brazilian protected areas

Although Brazil is a megadiverse country and thus a conservation priority, no study has yet quantified conservation gaps in the Brazilian protected areas (PAs) using extensive empirical data. Here, we evaluate the degree of biodiversity protection and knowledge within all the Brazilian PAs through a gap analysis of vertebrate, arthropod and angiosperm occurrences and phylogenetic data. Our results show that the knowledge on biodiversity in most Brazilian PAs remain scant as 71% of PAs have less than 0.01 species records per km2. Almost 55% of Brazilian species and about 40% of evolutionary lineages are not found in PAs, while most species have less than 30% of their geographic distribution within PAs. Moreover, the current PA network fails to protect the majority of endemic species. Most importantly, these results are similar for all taxonomic groups analysed here. The methods and results of our countrywide assessment are suggested to help design further inventories in order to map and secure the key biodiversity of the Brazilian PAs. In addition, our study illustrates the most common biodiversity knowledge shortfalls in the tropics.

Two New Cave-Dwelling Species of the Short-Tailed Whipscorpion Genus Rowlandius (Arachnida: Schizomida: Hubbardiidae) from Northeastern Brazil, with Comments on Male Dimorphism

Two new species of the arachnid order Schizomida, Rowlandius ubajara sp.nov. and Rowlandius potiguar sp.nov., are described based on both male and female specimens collected in caves from northeastern Brazil. Rowlandius ubajara is known only from the Ubajara Cave, in the state of Ceará; R. potiguar is recorded from 20 caves of the Apodi Limestone Group, in the state of Rio Grande do Norte. A remarkable dimorphism in male pedipalp length is described and analyzed in R. potiguar. The distribution of male pedipalp length is clearly bimodal in the species, but the two male morphs (homeomorphic and heteromorphic) present some overlap in the sizes of this structure. Moreover, males show a steeper allometry in pedipalp length than females, indicating that this trait is under a different selective regime in males and in females.

Aranhas (Araneae, Arachnida) do Estado de São Paulo, Brasil: diversidade, esforço amostral e estado do conhecimento

In this study we present a database of spiders described and registered from the Neotropical region between 1757 and 2008. Results are focused on the diversity of the group in the State of Sao Paulo, compared to other Brazilian states. Data was compiled from over 25,000 records, published in scientific papers dealing with Neotropical fauna. These records enabled the evaluation of the current distribution of the species, the definition of collection gaps and priority biomes, and even future areas of endemism for Brazil. A total of 875 species, distributed in 50 families, have been described from the State of Sao Paulo. A total of 11,280 species have been recorded from the Neotropical region (almost 1/3 of the species described worldwide). Brazil is the Neotropical country with the highest diversity (3,203 spp.), followed by Mexico (1,951 spp.) and Panama (1,325 spp.). Seven thousand five hundred species were recorded from South America and Brazil holds the highest diversity (3,203 spp., in 72 families), followed by Argentina (1,316 spp.), and Peru (1,066 spp.).

The Brazilian Goblin Spiders of the New Genus Predatoroonops (Araneae: Oonopidae)

Abstract The new endemic goblin spider genus Predatoroonops is erected for 17 new soft-bodied oonopid species from Brazil: Predatoroonops schwarzeneggeri, sp. nov., is the type species of the genus, P. poncho, sp. nov., P. billy, sp. nov., P. valverde, sp. nov., P. blain, sp. nov., P. maceliot, sp. nov., P. anna, sp. nov., P. rickhawkins, sp. nov., P. dutch, sp. nov., P. dillon, sp. nov., P. vallarta, sp. nov., P. phillips, sp. nov., P. yautja, sp. nov., P. peterharlli, sp. nov., P. mctiernani, sp. nov., P. chicano, sp. nov., and P. olddemon, sp. nov. Males of this new genus are easily diagnosed and separated from other Oonopinae genera by the extremely modified male chelicerae that frontally have median furrows and accentuated projections. The females can be recognized by the genitalia, which have a conspicuous posterior receptaculum, usually exposed between the epigastric folds. An auxiliary character for both sexes could be the presence of very long pairs of ventral spines with pronounced bases on the legs I and II tibiae and metatarsi. The genus is considered endemic and the species are recorded mainly from the Brazilian Atlantic Forest. An identification key is provided for all Predatoroonops species known to date.

Biogeography of Amazon birds: rivers limit species composition, but not areas of endemism

Amazonian rivers are usually suggested as dispersal barriers, limiting biogeographic units. This is evident in a widely accepted Areas of Endemism (AoEs) hypothesis proposed for Amazonian birds. We empirically test this hypothesis based on quantitative analyses of species distribution. We compiled a database of bird species and subspecies distribution records, and used this dataset to identify AoEs through three different methods. Our results show that the currently accepted Amazonian AoEs are not consistent with areas identified, which were generally congruent among datasets and methods. Some Amazonian rivers represent limits of AoEs, but these areas are not congruent with those previously proposed. However, spatial variation in species composition is correlated with largest Amazonian rivers. Overall, the previously proposed Amazonian AoEs are not consistent with the evidence from bird distribution. However, the fact that major rivers coincide with breaks in species composition suggest they can act as dispersal barriers, though not necessarily for all bird taxa. This scenario indicates a more complex picture of the Amazonian bird distribution than previously imagined.

Effectiveness of sampling methods and further sampling for accessing spider diversity: a case study in a Brazilian Atlantic rainforest fragment

The current biodiversity crisis makes the quantification of the diversity and the description of organism distribution particularly pressing. Biological inventories are among the most effective ways to improve the knowledge about local biota, but they can be very time and money‐consuming. The determination of adequate sampling effort and the selection of cost‐effective collecting methods are critical issues. In this article, a spider diversity inventory in an Atlantic semi‐deciduous forest fragment in Brazil was used to compare the efficiency of three collecting methods in two different seasons in order to propose an optimised sampling protocol. The worthiness of increasing sampling effort in the target area and similar tropical ecosystems was estimated and evaluated in terms of its cost‐effectiveness. For a better sampling of the spider community, it is suggested that a proportion of 55, 29 and 16% of total sampling hours should be dedicated to nocturnal hand collecting (NHC), pitfall traps and beating trays, respectively, in the rainy season. If only one method can be applied, the most efficient in terms of species per sampling is the NHC. A completeness of 70% of the estimated spider species richness (as predicted by the Chao1 estimator) was observed in the complete inventory and increasing sampling effort in the studied area may be highly ineffective when the costs involved are considered. Other studies in similar tropical rainforest areas also presented completeness around 70%, which might be a threshold from which the sampling effort necessary to raise the observed species richness substantially starts to be ineffective.

A Revision of the Neotropical Goblin Spider Genus Neoxyphinus Birabén, 1953 (Araneae, Oonopidae)

ABSTRACT The Neotropical spider genus Neoxyphinus Birabén, 1953, is revised, comprising 10 species found from the West Indies to northern Argentina. The genus is characterized by a unique combination of characters, which include the presence of a set of low tubercles or large spikes on the posterior surface of carapace; male endites with an apical, retrolateral excavation bearing a subapical toothlike apophysis; palpal bulb strongly inflated; embolus compact, S-shaped, with large, round ejaculatory opening; epigynal atrium large, with angular lateral corners. The large, round ejaculatory duct may be a synapomorphy of the genus. The genus Hawkeswoodoonops Makhan and Ezzatpanah, 2011, is synonymized with Neoxyphinus and the two species included in that genus are considered as nomina dubia. The monotypic genus Decuana Dumitrescu and Georgescu, 1987, is also synonymized with Neoxyphinus and its type species, D. hispida Dumitrescu and Georgescu, 1987, is transferred to the genus and redescribed. Confirming a hypothesis raised in the literature, Dysderina termitophila Bristowe, 1938, is transferred to Neoxyphinus and recognized as the senior synonym of the type species N. ogloblini Birabén, 1953. Two other species are transferred from Dysderina to Neoxyphinus: D. keyserlingi Simon, 1907, here recognized as the senior synonym of D. rugosa Bristowe, 1938, and D. furtiva Chickering, 1968, of which the male is described for the first time. In addition to the redescription of N. termitophilus, n. comb., N. hispidus, n. comb., N. xyphinoides (Chamberlin and Ivie, 1942), N. keyserlingi, n. comb., and N. furtivus, n. comb., five new species are described: N. petrogoblin Abrahim and Ott, from the Amazon basin in Brazil, Colombia, Ecuador, and Peru; N. gregoblin Abrahim and Santos, from Venezuela; N. axe Abrahim and Brescovit, from Bahia, Brazil; N. boibumba Abrahim and Rheims, from Para, Brazil; and N. barreirosi Abrahim and Bonaldo, from Brazil, Colombia, Guyana, and Venezuela. With the exception of N. boibumba, known only from males, all new species are described from both sexes.