Guide to the Crustacea, Arachnida, Onychophora and Myriopoda : exhibited in the Department of zoology, British museum (Natural history) ... With 90 illustrations.

"The section on the Crustacea is written by Dr. W. T. Calman, that on the Arachnida and Myriopoda by Mr. A. S. Hirst, and the portions dealing respectively with the Onychophora and with the Pestastomida ... by Mr. F. Jeffrey Bell." - Pref.

Relationships among the three major lineages of the Acari (Arthropoda : Arachnida) inferred from small subunit rRNA: Paraphyly of the parasitiformes with respect to the opilioacariformes and relative rates of nucleotide substitution

We inferred phylogeny among the three major lineages of the Acari ( mites) from the small subunit rRNA gene. Our phylogeny indicates that the Opilioacariformes is the sister-group to the Ixodida+Holothyrida, not the Ixodida+Mesostigmata+Holothyrida, as previously thought. Support for this relationship increased when sites with the highest rates of nucleotide substitution, and thus the greatest potential for saturation with nucleotide substitutions, were removed. Indeed, the increase in support ( and resolution) was despite a 70% reduction in the number of parsimony-informative sites from 408 to 115. This shows that rather than 'noisy' sites having no impact on resolution of deep branches, 'noisy' sites have the potential to obscure phylogenetic relationships. The arrangement, Ixodida+Holothyrida+Opilioacariformes, however, may be an artefact of long-branch attraction since relative-rate tests showed that the Mesostigmata have significantly faster rates of nucleotide substitution than other parasitiform mites. Thus, the fast rates of nucleotide substitution of the Mesostigmata might have caused the Mesostigmata to be attracted to the outgroup in our trees. We tested the hypothesis that the high rate of nucleotide substitution in some mites was related to their short generation times. The Acari species that have high nucleotide substitution rates usually have short generation times; these mites also tend to be more active and thus have higher metabolic rates than other mites. Therefore, more than one factor may affect the rate of nucleotide substitution in these mites.

Opiliões (Arachnida: Opiliones) em remanescente florestal no município de Plácido de Castro, AC.

Os opiliões (Arachnida: Opiliones) são aracnídeos com ampla distribuição geográfica, sendo a maior parte das espécies registradas na região Neotropical. Esses organismos possuem baixa capacidade de dispersão, alto grau de endemismo e sensibilidade às mudanças ambientais, também participam da ciclagem da matéria orgânica do solo, visto que muitas espécies possuem o hábito alimentar detritívoro. Dada a importância desses organismos, objetivou-se com esse trabalho prospectar a fauna de opiliões em remanescente florestal localizado no município de Plácido de Castro, AC. Foram utilizados dois métodos de captura: armadilhas pitfall (captura passiva), dispostas em dois transectos, e procura livre noturna (coleta ativa). As armadilhas pitfall consistiram em copos plásticos de 500 mL, contendo uma solução de formaldeído a 1% e gotas de detergente neutro, sendo recolhidas semanalmente. As coletas ativas mensais foram realizadas por quatro pessoas, em um esforço de coleta de 1 h. As espécies de opiliões capturadas foram: Paecilaema marajoara, Paraprotus quadripunctatus, Taito kakera e Cynorta sp. (Cosmetidae); Geaya sp. (Sclerosomatidae) e quatro adultos e um imaturo, pertencentes à família Manaosbiidae. Todos os opiliões registrados nesse levantamento foram capturados pelo método de ?procura livre noturna?, sendo os gêneros Geaya e Cynorta, bem como a espécie P. quadripunctatus, registrados pela primeira vez no estado do Acre.

Harvest-ironman: heavy armature, and not its defensive secretions, protects a harvestman against a spider

Natural selection has caused prey species to evolve distinct defensive mechanisms. One of such mechanisms was the evolution of noxious or distasteful chemicals, which have appeared independently in a number of vertebrates and invertebrates. In detailed analyses of arthropod behaviour, scent gland secretions have consistently been shown to be responsible for repelling specific predators. Because using such chemicals is costly, animals with alternative cheaper defences are expected not to release such secretions when alternative options exist. In this study, we sought to determine the defensive mechanisms of the harvestman Discocyrtus invalidus, a heavy bodied species that bears a pair of repugnatorial glands. The spider Enoploctenus cyclothorax was used as the predator, and the cricket Gryllus sp. was used as a control. In a first set of experiments, the harvestmen were preyed upon significantly less than the crickets. In two other experiments, we found that harvestmen did not use their scent gland secretions to deter the predator. Moreover, results of a fourth experiment revealed that these spiders are not repelled by defensive secretions. Discocyrtus invalidus has a thick cuticle on the entire body: scanning electron micrographs revealed that only the mouth, the articulations of appendages and the tips of the legs are not covered by a hard integument. In a fifth experiment, we found that these spiders had difficulty piercing the harvestmen body. This is the first experimental evidence that a chemically defended arachnid does not use its scent gland secretions to repel a much larger predator but instead relies on its heavily built body. (c) 2010 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Evaluation of the aquatic macroinvertebrate community as a tool for monitoring a reservoir in the Pitangui river basin, Parana, Brazil

Evaluation of the aquatic macroinvertebrate community as a tool for monitoring a reservoir in the Pitangui river basin, Parana, Brazil. Benthic and nektonic macroinvertebrates play an important role in the structure and function of aquatic ecosystems and their distribution is influenced by chemical features of the substrate, vegetation composition, and water depth. Knowledge on the fauna contributes to the assessment of water quality and development of biodiversity conservation activities. Different biotic factors affecting the invertebrate community were evaluated in the Alagados reservoir, the main water source of the city of Ponta Grossa, Parana. In five different sampling points, 18,473 specimens of aquatic or semiaquatic macroinvertebrates were collected, belonging to 46 taxa of the phylla Annelida (Hirudinea and Oligochaeta), Mollusca (Gastropoda), Platyhelminthes (Turbellaria), Nematoda and Arthropoda (Arachnida, Crustacea and Insecta). This community was composed mainly of predators (45.7% of the taxa sampled), collectors and/or filterers (23.9%), scrapers (15.2%), shredders (13.0%) and detritivores (2.2%). Diversity (H`) and evenness (J) indices were significantly low for the sites examined, and H` ranged between 0.3301 and 1.0396. Regarding tolerance of organisms to organic pollution, more sensitive taxa were very rare (Plecoptera) or unusual (Trichoptera and Ephemeroptera). Among the more resistant groups are Chironomidae and Hirudinea, both fairly common in the samples. This study corroborates the importance of bioindicators as a tool to assess water quality for human consumption and for the conservation of aquatic environments, integrating physical, chemical and biological factors in monitoring programs.

Escorpionismo em Belo Horizonte, MG: um estudo retrospectivo

Os escorpiões (Arachnida, Scorpiones), especialmente na área urbana, devido à grande densidade demográfica e possibilidade de confronto, representam risco à saúde pública. A espécie Tityus serrulatus é a mais importante, do ponto de vista médico, causando o maior número de acidentes. Objetivou-se levantar dados epidemiológicos e a ocorrência de acidentes escorpiônicos em Belo Horizonte, entre 1990 e 1997. Os dados foram obtidos no Hospital de Pronto Socorro João XXIII. Ocorreram 3265 acidentes, sendo a maioria em 1996. Aconteceram 6 acidentes fatais. Com maior incidência nos meses de janeiro, o sexo masculino, os membros superiores e a faixa etária entre 25 e 65 anos, foram os mais atingidos. Os resultados constituem importante subsídio para o controle do escorpionismo, pois delimitam as áreas mais atingidas e o perfil dos acidentados, permitindo campanhas educativas e de prevenção mais eficientes.

Venomous and poisonous arthropods: identification, clinical manifestations of envenomation, and treatments used in human injuries

Abstract This review presents the main species of venomous and poisonous arthropods, with commentary on the clinical manifestations provoked by the toxins and therapeutic measures used to treat human envenomations. The groups of arthopods discussed include the class Arachnida (spiders and scorpions, which are responsible for many injuries reported worldwide, including Brazil); the subphylum Myriapoda, with the classes Chilopoda and Diplopoda (centipedes and millipedes); and the subphylum Hexapoda, with the class Insecta and the orders Coleoptera (beetles), Hemiptera (stink bugs, giant water bugs, and cicadas), Hymenoptera (ants, wasps, and bees), and Lepidoptera (butterflies and moths).

Biologia Centrali-Americana :zoology, botany and archaeology /edited by Frederick Ducane Godman and Osbert Salvin.

Arachnida Araneidea

Biologia Centrali-Americana :zoology, botany and archaeology /edited by Frederick Ducane Godman and Osbert Salvin.

Arachnida Araneidea and Opiliones

Biologia Centrali-Americana :zoology, botany and archaeology /edited by Frederick Ducane Godman and Osbert Salvin.

Arachnida, Scorpiones, Pedipalpi, and Solifugae

Biologia Centrali-Americana :zoology, botany and archaeology /edited by Frederick Ducane Godman and Osbert Salvin.

Arachnida Acaridea