Arthropods

The world’s deepest subterranean community - Krubera-Voronja Cave (Western Caucasus)

by Ana Sofia Reboleira

Sendra, Alberto and Ana Sofia P.S. Reboleira. 2012. The world’s deepest subterranean community - Krubera-Voronja Cave (Western Caucasus). International Journal of Speleology, 41 (2): 221-230.

Subsurface biota extends over a wide variety of habitats that can be spatially interconnected. The largest communities... more Subsurface biota extends over a wide variety of habitats that can be spatially interconnected. The largest communities of this subsurface biota inhabit cavities and are well known mainly in caves where biologists are able to have access. Data about deep subterranean communities and arthropods living under one thousand meters was unknown.
An expedition to world’s deepest cave, Krubera-Voronja in Western Caucasus, revealed an interesting subterranean community, living below 2000 meters and represented by more than 12 species of arthropods, including several new species for science. This deep cave biota is composed of troglobionts and also epigean species, that can penetrate until -2140 m. Deep subterranean ecosystems should not be seen only as an evolutionary dead end towards the troglomorphic syndrome, but also as a shelter for epigean species populations, especially during long periods of time when surface conditions are severe for their survival. Most of the subsurface biota depends on allochthonous sources of organic carbon coming from: water percolating from the surface, sinking streams that enter caves, and activities of animals moving in and out of caves.
The biocoenosis and the vertical distribution of invertebrate fauna of Krubera-Voronja are provided, from its entrance to the remarkable depth of 2140 meters, including the discovery of world’s deepest dwelling arthropod.

Keywords: deep subsurface biosphere; biospeleology; vertical distribution; Krubera-Voronja; Western Caucasus

Budd & Telford, 2009. Nature_the origin and Evolution of Arthropods

by Gustavo Miranda

Arthropod colonisation of a debris-covered Glacier

by Marco Isaia

Tick saliva induces regulatory dendritic cells: MAP-kinases and Toll-like receptor-2 expression as potential targets

by Fredy RS Gutierrez

Oliveira CJ, Carvalho WA, Garcia GR, Gutierrez FR, de Miranda Santos IK, Silva JS, Ferreira BR.
Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto, University of São Paulo, SP, Brazil.

Ticks (Acari: Ixodidae) are bloodsucking ectoparasitic arthropods of human and veterinary medical importance. Tick... more Ticks (Acari: Ixodidae) are bloodsucking ectoparasitic arthropods of human and veterinary medical importance. Tick saliva has been shown to contain a wide range of bioactive molecules with vasodilatory, antihemostatic, and immunomodulatory activities. We have previously demonstrated that saliva from Rhipicephalus sanguineus ticks inhibits the maturation of dendritic cells (DCs) stimulated with LPS. Here we examined the mechanism of this immune subversion, evaluating the effect of tick saliva on Toll-like receptor (TLR)-4 signalling pathway in bone marrow-derived DCs. We demonstrated that R. sanguineus tick saliva impairs maturation of DCs stimulated with LPS, a TLR-4 ligand, leading to increased production of interleukin (IL)-10 and reduced synthesis of IL-12p70 and TNF-alpha. The immunomodulatory effect of the tick saliva on the production of pro-inflammatory cytokines by DCs stimulated with LPS was associated with the observation that tick saliva inhibits the activation of the ERK 1/2 and p38 MAP kinases. These effects were independent of the expression of TLR-4 on the surface of DCs. Additionally, saliva-treated DCs also presented a similar pattern of cytokine modulation in response to other TLR ligands. Since the recent literature reports that several parasites evade immune responses through TLR-2-mediated production of IL-10, we evaluated the effect of tick saliva on the percentage of TLR-2(+) DCs stimulated with the TLR-2 ligand lipoteicoic acid (LTA). The data showed that the population of DCs expressing TLR-2 was significantly increased in DCs treated with LTA plus saliva. In addition, tick saliva alone increased the expression of TLR-2 in a dose- and time-dependent manner. Our data suggest that tick saliva induces regulatory DCs, which secrete IL-10 and low levels of IL-12 and TNF-alpha when stimulated by TLR ligands. Such regulatory DCs are associated with expression of TLR-2 and inhibition of ERK and p38, which promotes the production of IL-10 and thus down-modulates the host's immune response, possibly favouring susceptibility to tick infestations.

Confirmation of Romer's Gap as a low oxygen interval constraining the timing of initial arthropod and vertebrate terrestrialization

by Michel Laurin

Lee, M.S.Y. Jago, J.B., García-Bellido, D.C., Edgecombe, G.D., Gehling, J.G., Paterson, J.R. 2011. Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia. Nature 474: 631-634

by Michael S. Y. Lee

For the movie version, see here!
http://www.youtube.com/watch?v=WQE3x8zp3jc

For coverage by National Geographic and other media see here:
http://news.nationalgeographic.com/news/2011/07/pictures/110711-fossil-eyes-advanced-shrimp-predator-science-lenses/
http://www.cosmosmagazine.com/news/4460/scientists-see-rapid-evolution-ancient-eyes
http://scienceblogs.com/pharyngula/2011/06/complex_eyes_in_the_cambrian.php
http://www.australiangeographic.com.au/journal/complex-vision-evolved-earlier-than-thought.htm
http://www.theaustralian.com.au/national-affairs/kangaroo-island-discovery-opens-eyes-to-cambrian-life/story-fn59niix-1226084469988
http://www.adelaidenow.com.au/ipad/cambrian-eye-fossil-find-revealed-in-science-journal-nature/story-fn6bqphm-1226084493013

Paterson, J. R., Jago, J. B., Gehling, J. G., Garcia-Bellido, D. C., Edgecomb, G. D. and Lee, M.S.Y. 2008. Early Cambrian arthropods from the Emu Bay shale Lagerstatte, South Australia. I. Rabano, R. Gozalo and D. Garcia-Bellido (eds). Advances in Trilobite Research. Spanish Institude of Geology and Mineralogy, Madrid. pp319-326.

by Michael S. Y. Lee

For coverage of the general excavation see here:
http://www.abc.net.au/rn/scienceshow/stories/2010/2949557.htm
http://scienceblogs.com/evolvingthoughts/2008/08/precambrian_fossils_at_kangaro.php
http://www.abc.net.au/btn/story/s2364705.htm
http://www.cosmosmagazine.com/node/4106/full
http://www.abc.net.au/catalyst/stories/2347748.htm

Garcia-Bellido, D., Paterson, J. R., Edgecombe, G.D., Jago, J., Gehling, J.G., Lee, M.S.Y. 2009. Bivalved arthropods Tuzoia and Isoxys with soft part tissue preservation from the Cambrian Emu Bay shale (Kangaroo Island, Australia). Palaeontology 52: 1221-1241

by Michael S. Y. Lee

For coverage of the general excavation see here:
http://www.abc.net.au/rn/scienceshow/stories/2010/2949557.htm
http://scienceblogs.com/evolvingthoughts/2008/08/precambrian_fossils_at_kangaro.php
http://www.abc.net.au/btn/story/s2364705.htm
http://www.cosmosmagazine.com/node/4106/full
http://www.abc.net.au/catalyst/stories/2347748.htm

Sanders, K.L., Lee, M.S.Y. 2010. Arthropod molecular divergence times and the Cambrian origin of pentastomids. Systematics and Biodiversity 8:1, 63 - 74

by Michael S. Y. Lee