First characterization of the behavioral repertory in a ricinulid: Cryptocellus narino Platnick & Paz 1979 (Arachnida, Ricinulei, Ricinoididae)

Ricinuleids are considered one of the most enigmatic and neglected arachnid orders. The low diversity and poor local abundance of several species, makes the study of most aspects related to biology and behavior of this group very difficult. Most of the current knowledge related to ricinuleid biology relies on anecdotal observations. So far, no published studies exist that describe in detail ricinuleid behavior. Here we present the behavioral repertory of a ricinuleid, the Neotropical species Cryptocellus narino. Eighteen individuals (six males, six females and six immatures) were examined under laboratory conditions to describe and quantify their behavioral repertory and its variation along the day. The behavioral repertory in males exhibited a higher number of behavioral acts when compared to females and immatures. The most frequent behavioral categories were “resting”, “exploring” and “feeding”. “Resting” was the most common behavior during the photophase, while “feeding” and “exploring” were the most common during scotophase, suggesting this species is predominantly nocturnal. This study also provides behaviors previously not known for this group as well as a description of the daily schedule. We expect this work will become a baseline study for further research on ricinuleid ethology.Fil: Garcia, L. F.. Instituto de Invest. Biologicas "clemente Estable"; UruguayFil: Torrado León, E.. Universidad Nacional de Colombia; ColombiaFil: Tallarico, G.. University of Greifswald; AlemaniaFil: Peretti, Alfredo Vicente. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin

Volcanic-Island Lateral Collapses and Their Submarine Deposits

Landslide deposits offshore many volcanic islands provide evidence of catastrophic lateral collapses. These deposits span a larger volume range than their continental equivalents, and can generate devastating tsunamis. All historical volcanic-island lateral collapses have occurred in arc settings, and have been characterised by rapid failure and efficient tsunami generation. The varied morphology of their deposits is influenced both by lithological properties and the nature of the substrate. Many deposits show evidence of extensive seafloor erosion and transformation into debris flows, and the propagation of frontally-confined sediment deformation beyond and beneath the primary deposit. Mobilised volumes can far exceed that of the initial failure, and accurate deposit interpretation requires internal geophysical imaging and sampling. Around intraplate ocean-island volcanoes, multi-unit turbidites suggest that lateral collapses may occur in discrete stages; although this would reduce their overall tsunamigenic potential, the volumes of individual stages of collapse remain very large. Numerical models of both landslide and tsunami processes in ocean-island settings are difficult to test, and the smaller collapses that typify island arcs are an important focus of research due to their higher global frequency, availability of direct failure and tsunami observations, and a need to better understand the signals of incipient collapse to develop approaches for tsunami hazard mitigation