Sidclay C. Dias

Seasonal variations in scorpion activities (Arachnida: Scorpiones) in an area of Caatinga vegetation in northeastern Brazil

Seasonal variations in scorpion activity were investigated during a 24 month period in an area of Caatinga (dryland) vegetation in the state of Paraiba, Brazil. The total number of scorpions captured was correlated with climatic variables and prey abundance. Scorpions were captured monthly using pitfall traps; their potential prey was captured using malaise, beating trays and pitfalls. A total of 104 scorpions were captured, representing four species: the bothriurids Bothriurus asper (Pocock, 1893) (n = 74; 71.2%) and B. rochai (Mello-Leitao, 1932) (n = 20; 19.2%), and the buthids Rhopalurus rochai (Borelli, 1910) (n = 4; 3.8%) and Tityus stigmurus (Thorell, 1876) (n = 1; 1.0%). The sex ratios (male:female) of the two most abundant species were 14:1 for B. asper and 7:1 for B. rochai. The abundance of scorpions captured was significantly correlated with precipitation, real evapotranspiration, and abundance of invertebrates (mainly insects). Scorpion activities, especially those of B. asper and B. rochai, may be closely related to their reproductive cycles. Reproduction apparently reaches its maximum when there is an abundance of food, which in the Caatinga is strongly associated with rainfall patterns.

Species richness and seasonality of spiders (Arachnida, Araneae) in an urban Atlantic Forest fragment in Northeastern Brazil

Species richness and forest seasonality of spiders in an urban fragment of Northeastern Brazil were investigated. Mata do Buraquinho is a remnant of Atlantic Rain Forest where no spider inventories have ever been made. Samplings during dry and wet seasons were carried out in order to establish if seasonality influences species richness and complementarily of the spider fauna. Pitfall traps, nocturnal collections, and beating tray samples were used to access a multi-guild spider fauna. Spider species were estimated using first order Jackknife method. Four hundred samples were obtained, resulting in 1681 adult spiders. A total of 166 species were recorded and 211 were estimated. No significant differences for species richness were observed between both periods, and the captured species were the same according to the complementarily coefficients. The fragmentation hypothesis as factor of biota impoverishment was not tested, but future investigations on this topic are suggested in the complex of forest remnants in João Pessoa.

A structured inventory of spiders (Arachnida, Araneae) in natural and artificial forest gaps at Porto Urucu, Western Brazilian Amazonia

A preliminary survey of the spider fauna in natural and artificial forest gap formations at “Porto Urucu”, a petroleum/natural gas production facility in the Urucu river basin, Coari, Amazonas, Brazil is presented. Sampling was conducted both occasionally and using a protocol composed of a suite of techniques: beating trays (32 samples), nocturnal manual samplings (48), sweeping nets (16), Winkler extractors (24), and pitfall traps (120). A total of 4201 spiders, belonging to 43 families and 393 morphospecies, were collected during the dry season, in July, 2003. Excluding the occasional samples, the observed richness was 357 species. In a performance test of seven species richness estimators, the Incidence Based Coverage Estimator (ICE) was the best fit estimator, with 639 estimated species. To evaluate differences in species richness associated with natural and artificial gaps, samples from between the center of the gaps up to 300 meters inside the adjacent forest matrix were compared through the inspection of the confidence intervals of individual-based rarefaction curves for each treatment. The observed species richness was significantly higher in natural gaps combined with adjacent forest than in the artificial gaps combined with adjacent forest. Moreover, a community similarity analysis between the fauna collected under both treatments demonstrated that there were considerable differences in species composition. The significantly higher abundance of Lycosidae in artificial gap forest is explained by the presence of herbaceous vegetation in the gaps themselves. Ctenidae was significantly more abundant in the natural gap forest, probable due to the increase of shelter availability provided by the fallen trees in the gaps themselves. Both families are identified as potential indicators of environmental change related to the establishment or recovery of artificial gaps in the study area.

Scorpionism in the rural zone of Teresina, State of Piauí: relate of envenomation cases

1. Laboratório de Aracnologia, Museu Paraense Emílio Goeldi, Laboratório de Aracnologia, Belém, PA. 2. Laboratório de Zoologia, Departamento de Zoologia, Universidade Federal do Piauí, Teresina, PI. Endereço para corrrespondência: Sr. Leonardo Sousa Carvalho. Laboratório de Aracnologia/Museu Paraense Emílio Goeldi. Campus de Pesquisa. Av. Perimetral 1901, Caixa Postal 399, 66017-970 Belém, PA. e-mail: leosc_fla@yahoo.com.br Recebido em:16/01/2007 Aceito em: 23/05/2007 No Brasil, o acidente escorpiônico constitui um problema atual de saúde pública, não só pela alta incidência em determinadas regiões, como pela sua potencialidade em ocasionar quadros graves, às vezes fatais, principalmente em crianças . No Estado do Piauí, nenhum caso de escorpionismo havia sido relatado até o momento. Realizamos uma entrevista com dois moradores da zona rural de Teresina que sofreram acidentes com escorpiões a fim de sabermos a espécie causadora e as manifestações do envenenamento. A identificação dos escorpiões foi feita comparando-se as descrições fornecidas pelos moradores com chaves de identificação propostas 3 . O primeiro acidente ocorreu com uma mulher de 54 anos no dia 14 de fevereiro de 2004. A paciente foi encaminhada ao hospital com dor local de forte intensidade, agitação, sialorréia, taquicardia, visão embaçada, lacrimejando, espasmos musculares e hipotensão arterial. Ficou em observação no hospital, onde não havia soro anti-escorpiônico, por dois dias. Uma coleta na área da ocorrência do acidente levou à captura de sete espécimes, todos Rhopalurus agamemnon (C.L. Koch, 1839). O segundo acidente ocorreu com um jovem de 18 anos no dia três de outubro de 2004. O paciente, atingido no 2o quirodáctilo, foi socorrido precocemente e apresentava-se com dor local intensa, sialorréia, sonolência e dor irradiada no ombro direito. Ficou em observação no hospital por 24 horas após receber soro anti-escorpiônico. Não levou o escorpião para identificação, mas o descreveu com características similares a Rhopalurus agamemnon. Os dois pacientes foram atendidos precocemente, lavaram o local da picada, não fizeram incisões ou torniquetes e não tomaram medicamento sem prescrição médica. Rhopalurus agamemnon, é um animal que se distribui pelos Estados do Piauí, Goiás, Bahia, Ceará, Mato Grosso e Pernambuco . É caracterizado pelo grande tamanho, podendo chegar a 110mm de comprimento total, e possui coloração de modo geral marrom, pernas amareladas, pedipalpos com tons marrons/amarelados, segmentos metassomais I a III amarelos/marrons, IV e V mais escuros ou quase negros. São, geralmente, encontrados em vegetações abertas 3 . Há espécimes registrados para Piracuruca, Castelo do Piauí, União, Teresina, José de Freitas e São Raimundo Nonato, no Estado do Piauí.

Climatic Variables Do Not Directly Predict Spider Richness and Abundance in Semiarid Caatinga Vegetation, Brazil

ABSTRACT Spiders are abundant in tropical ecosystems and exert predatory pressure on a wide variety of invertebrate populations and also serve as prey for many others organisms, being part of complex interrelationships influenced directly and indirectly by a myriad of factors. We examined the influence of biotic (i.e., prey availability) and abiotic (i.e., temperature, precipitation, relative humidity, real evapotranspiration) factors on species richness and abundance during a two-year period in the semiarid Caatinga vegetation in northeastern Brazil. Data were analyzed through partial autocorrelation functions, cross correlations, and a path analysis. A total of 2522 spiders were collected with beating tray, pitfall traps, and malaise traps, comprising 91 species and 34 families. Spider abundance peaked in the rainy season. Our results suggest that total invertebrate abundance has a direct influence on spider richness and abundance, whereas the effects of precipitation were mainly indirectly related to most spider assemblage parameters. The increase in vegetation cover with the rainy season in the Caatinga provides more breeding and foraging sites for spiders and stimulates their activities. Additionally, rainfall in arid and semiarid ecosystems stimulated the activity and reproduction of many herbivore and detritivore invertebrates dependent on plant biomass and necromass consumption, leading to an increase in spider prey availability.

On the female of Metagonia taruma (Araneae: Pholcidae), ecology of the pholcid spiders in the Urucu River Basin, Amazonas, Brazil and new records from Brazilian Amazonia

In this study we describe the unknown female of Metagonia taruma Huber, 2000, which was discovered after sampling in two forest gap types at Porto Urucu (Urucu River Basin, Coari, Amazonas, Brazil), and also provide information on the community ecology and natural history of the sampled species. The female of M. taruma is similar to that of M. samiria (Huber, 2000) by having an epigynum with a slightly projecting broad scape with a distal pocket; it differs by the larger pore plates. We collected twelve Pholcidae species at Porto Urucu and M. taruma was the most frequent and abundant. The populations of Carapoia ocaina Huber, 2000 and Mesabolivar aurantiacus (Mello-Leitao, 1930) present homogeneous sex ratios, while M. taruma and Mesabolivar sp. were female biased. Only two species (M. taruma and Mesabolivar sp. ) exhibited differences in abundance in each forest gap type, being higher at the poorly regenerated gaps. Thus, the use of Pholcidae species as ecological indicators is promising. We also present new records, throughout the Amazon Basin, for the Pholcidae species collected at Porto Urucu.

A new species of Goeldia (Araneae: Titanoecidae) with notes on its natural history

A new species of Goeldia Keyserling, 1891 is described. Goeldia is the only genus of Titanoecidae with species in the Neotropical region and includes eight species diagnosed by the presence of a patellar process in the male palp. The new species, Goeldia zyngierae sp. nov., was found living inside the Casa de Pedra cave, Ribeira, Itabaiana, Sergipe, Brazil. Goeldia zyngierae sp. nov. is diagnosed by the tegular process with a small constriction near the base of the dorsal part and by a distal narrowing, more visible in the dorsal side of the patellar process of the male palp. The female epigynum shows a pair of sinuous depressions and a large mid field that does not close the copulatory openings as in Goeldia luteipes Keyserling, 1878. The vulva presents a narrow and straight copulatory duct in comparison with those of Goeldia mexicana Pickard-Cambridge, 1896 and a narrow spermathecae. The description includes illustrations of the genital organs, measurements of the body and legs and leg spination. Notes on the natural history show that inside the cave the spiders live farther than the first 40 m, in the aphotic zone, under stones or on the wall. They were never observed alone or walking on the ground, and the webs contained two to thirty spiders of different life stages, living together, suggesting a possible cooperative behavior. Further field work is needed to confirm and understand the degree of sociability of this new species, if this species is restricted to caves, and if this behavior occurs only inside the caves.

Arachnids from Araripe Plateau, Ceará, Brazil

The Araripe Plateau is situated in the states of Ceara, Piaui and Pernambuco, northeastern Brazil, in the Caatinga biome, semiarid domain. This region of Brazil is characterized by high temperatures and low rainfall. Nevertheless, due to its high elevation and large amount of orographic rainfall, the Araripe Plateau is an exception as a seasonal semi-deciduous forest with high humidity in the semiarid domain and the Caatinga biome. Herein a species list of Araripe Plateau arachnids is presented from the compilation of data from in situ sampling from January to May 2013, from the literature, and from Brazilian arachnid collections data. A total of 68 species were recorded for the area, of which 53 were spiders, eight harvestmen and seven scorpions. The species richness recorded here is considered significant regarding the known diversity of Arachnida in the semiarid region and contributes to expanding our knowledge of the area.

First record of an onychophoran (Onychophora, Peripatidae) feeding on a theraphosid spider (Araneae, Theraphosidae)

Abstract A velvet worm (Peripatus sp., Peripatidae) was observed and photographed while feeding on a theraphosid spider, Hapalopus butantan (Pérez-Miles, 1998). The present note is the first report of an onychophoran feeding on “giant” spider.

Trade-offs in the use of multiple survey methods for spiders and harvestmen assemblages in an Amazonian upland forest

Invertebrates can be sampled using any of several established rapid and cost effective methods for documenting species richness and composition. Despite their many differences, different orders of arachnids have being often sampled together in various studies. Active nocturnal search has been long considered the most efficient method for sampling spiders and harvestmen. We compared the number of species and composition of spiders and harvestmen simultaneously sampled using three sampling methods: beating tray, active nocturnal search and Winkler extractors at areas along the Urucu river, Coari, Amazonas. We found that a reasonable inventorying of harvestmen can be accomplished solely by nocturnal search, whereas beating tray and Winkler approaches are redundant. For spiders, both nocturnal and beating tray were complementary and are needed to provide a more complete picture of spider assemblages. Financial and temporal costs of each method employed can be reduced in 39% and 46% respectively. Based on our findings, we propose that different taxonomic groups (e.g. harvestmen and spiders) should be sampled separately in tropical forests, especially for monitoring purposes. The three methods employed are expensive and time-consuming and should only be used combined when advantageous.