Complex social insect species exhibit task specialization mediated by morphological and behavior-al traits.However,evidence of such traits is scarce for other social arthropods.We investigated whether the social pseud...Complex social insect species exhibit task specialization mediated by morphological and behavior-al traits.However,evidence of such traits is scarce for other social arthropods.We investigated whether the social pseudoscorpion Paratemnoides nidificator exhibits morphologically and behav-iorally specialized individuals in prey capture.We measured body and chela sizes of adult pseudo-scorpions and analyzed predation processes.Larger individuals spent more time moving through the colony and foraging than smaller pseudoscorpions.Individuals that captured prey had increased body and absolute chelae sizes.Although larger individuals had relatively small chelae size,they showed a higher probability of prey capture.Larger individuals manipulated prey often,although they fed less than smaller pseudoscorpions.Individuals that initiated captures fed more frequently and for more time than the others.Natural selection might be favoring individuals speci-alized in foraging and colony protection,allowing smaller and less efficient adults to avoid contact with dangerous prey.To our knowledge,there is incipient information regarding specialized indi-viduals in arachnids,and our results might indicate the emergence of a morphologically special-ized group in this species.展开更多
Climate warming has been more pronounced in the Arctic than elsewhere, resulting in a recent rapid glacial retreat. Over 85% of the Almajallojekna glacier has disappeared over the last 115 years and it is one of the f...Climate warming has been more pronounced in the Arctic than elsewhere, resulting in a recent rapid glacial retreat. Over 85% of the Almajallojekna glacier has disappeared over the last 115 years and it is one of the fastest retreating glaciers in Sweden. In 2011 and 2012, at 18 sites in the vicinity of the remaining glacier network, we sampled arthropods and related the species richness, abundance and proportion of herbivores to altitude （ranging from 824 to 1,524 m.a.s.1.） and the age of the site （ranging from 0 to 〉 115 years）. Temperature was measured at six sites and the average annual air temperature ranged from -3.7℃ to 1.1℃. In total, we recorded 3,705 arthropods from 117 species in nine different taxonomic groups. The most abundant and species-rich group was Coleoptera （1,381 individuals, 41 species） followed by Araneae （1,050 individuals, 15 species） and Macrolepidoptera （732 individuals, 17 species）. Only at lower altitudes did the abundance and species richness of arthropods increase with increasing age of the site. The results were consistent among the studied taxonomic groups and when controlling for sam- piing intensity using two different approaches. The proportion of herbivores decreased with increasing age of the site and with increasing altitude. Clearly, altitude appears more important than the age of the site and, at higher altitudes, abundance, species richness and herbivory are low [Current Zoology 60 （2）： 203-220, 2014].展开更多
Australian funnel-web spiders are arguably the most venomous spiders in the world,with much research focusing on this aspect of their biology.However,other aspects related to their life history,ecology and behaviour h...Australian funnel-web spiders are arguably the most venomous spiders in the world,with much research focusing on this aspect of their biology.However,other aspects related to their life history,ecology and behaviour have been overlooked.For the first time,we assessed repeatability.namely risk-taking behaviour,aggressiveness and activity in the contexts of predation,conspecific tolerance and exploration of a new territory in four species of Australian funnel-web spiders:two are closely related,Hadronyche valida and H.infensa,and two have overlapping distributions but occupy different habitats,H.cerberea and Atrax robustus.We also compared behaviors between species.At the species level,we found that H.valida showed consistency in risk-taking behavior when exposed to a predator stimulus,aggressiveness against conspecifics,and exploration of a new territory.In contrast,in the other species,only A.robustus showed repeatability in the context of exploration of a new territory.These results suggest that some behavioral traits are likely more flexible than others,and that the repeatability of behaviors may be species-specific in funnel-webs.When we compared species,we found differences in risk-taking behavior and defensiveness.This study provides novel insights to understanding variation in behavioral traits within and between species of funnel-web spiders,suggesting that some behavioral traits are likely context and/or species dependent,as a result of their evolutionary history.These findings provide key insights for understanding the ecological role of behavior and venom deployment in venomous animals,and a greater understanding of behavior in these medically significant and iconic spiders thatareof conservation concern.展开更多
Accidents caused by spider bites occur in many countries and represent a public health problem due to their high severity and occurrence of fatal accidents. In Veterinary Medicine, the incidence of arachnidism is cons...Accidents caused by spider bites occur in many countries and represent a public health problem due to their high severity and occurrence of fatal accidents. In Veterinary Medicine, the incidence of arachnidism is considered nonexistent in large animals, as their thick skin cannot be pierced, rare in cats and common in dogs, particularly due to their exploratory and curious habit, and the habitats of venomous animals, such as the arachnids, located close to urban areas. The aim of this review is to describe the characteristics and distribution of spiders, the mechanism of action of the venom, clinical signs, diagnosis and treatment of accidents caused by arachnids of genera Loxosceles sp., Phoneutria sp., Latrodectus sp., and suborder Mygalomorphae.展开更多
Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea....Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13 - 1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.24 - 1.27 g/ml) Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, and 89.3% of lipids presents in the hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids (phosphatidylcholine and phosphatidylethanolamine) and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. In order to confirm the role played by lipoproteic fractions in vitro assays with different 14C-lipid were performed. It was observed that Gr-VHDL takes up mainly free fatty acids and triacylglycerols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three proteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa, and other minority of 249 kDa. In conclusion, this study reports lipid characterization of the lipoproteic fractions present in the hemolymph of the tarantula, G. rosea. The role of each lipoproteic fraction in relation to lipid uptake is sustained by in vitro assays. Similarities and differences are found when it is compared to lipoproteins of only the three species of spiders studied.展开更多
基金This study was supported by the Coordenação de Aprleicoamento de Pessoal de Nível Superior(CAPES)-Finance Code 001-,the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),and the Fundacão de Amparo à Pesquisa do FEstado de Minas Gerais(FAPEMIG).
文摘Complex social insect species exhibit task specialization mediated by morphological and behavior-al traits.However,evidence of such traits is scarce for other social arthropods.We investigated whether the social pseudoscorpion Paratemnoides nidificator exhibits morphologically and behav-iorally specialized individuals in prey capture.We measured body and chela sizes of adult pseudo-scorpions and analyzed predation processes.Larger individuals spent more time moving through the colony and foraging than smaller pseudoscorpions.Individuals that captured prey had increased body and absolute chelae sizes.Although larger individuals had relatively small chelae size,they showed a higher probability of prey capture.Larger individuals manipulated prey often,although they fed less than smaller pseudoscorpions.Individuals that initiated captures fed more frequently and for more time than the others.Natural selection might be favoring individuals speci-alized in foraging and colony protection,allowing smaller and less efficient adults to avoid contact with dangerous prey.To our knowledge,there is incipient information regarding specialized indi-viduals in arachnids,and our results might indicate the emergence of a morphologically special-ized group in this species.
文摘Climate warming has been more pronounced in the Arctic than elsewhere, resulting in a recent rapid glacial retreat. Over 85% of the Almajallojekna glacier has disappeared over the last 115 years and it is one of the fastest retreating glaciers in Sweden. In 2011 and 2012, at 18 sites in the vicinity of the remaining glacier network, we sampled arthropods and related the species richness, abundance and proportion of herbivores to altitude （ranging from 824 to 1,524 m.a.s.1.） and the age of the site （ranging from 0 to 〉 115 years）. Temperature was measured at six sites and the average annual air temperature ranged from -3.7℃ to 1.1℃. In total, we recorded 3,705 arthropods from 117 species in nine different taxonomic groups. The most abundant and species-rich group was Coleoptera （1,381 individuals, 41 species） followed by Araneae （1,050 individuals, 15 species） and Macrolepidoptera （732 individuals, 17 species）. Only at lower altitudes did the abundance and species richness of arthropods increase with increasing age of the site. The results were consistent among the studied taxonomic groups and when controlling for sam- piing intensity using two different approaches. The proportion of herbivores decreased with increasing age of the site and with increasing altitude. Clearly, altitude appears more important than the age of the site and, at higher altitudes, abundance, species richness and herbivory are low [Current Zoology 60 （2）： 203-220, 2014].
文摘Australian funnel-web spiders are arguably the most venomous spiders in the world,with much research focusing on this aspect of their biology.However,other aspects related to their life history,ecology and behaviour have been overlooked.For the first time,we assessed repeatability.namely risk-taking behaviour,aggressiveness and activity in the contexts of predation,conspecific tolerance and exploration of a new territory in four species of Australian funnel-web spiders:two are closely related,Hadronyche valida and H.infensa,and two have overlapping distributions but occupy different habitats,H.cerberea and Atrax robustus.We also compared behaviors between species.At the species level,we found that H.valida showed consistency in risk-taking behavior when exposed to a predator stimulus,aggressiveness against conspecifics,and exploration of a new territory.In contrast,in the other species,only A.robustus showed repeatability in the context of exploration of a new territory.These results suggest that some behavioral traits are likely more flexible than others,and that the repeatability of behaviors may be species-specific in funnel-webs.When we compared species,we found differences in risk-taking behavior and defensiveness.This study provides novel insights to understanding variation in behavioral traits within and between species of funnel-web spiders,suggesting that some behavioral traits are likely context and/or species dependent,as a result of their evolutionary history.These findings provide key insights for understanding the ecological role of behavior and venom deployment in venomous animals,and a greater understanding of behavior in these medically significant and iconic spiders thatareof conservation concern.
文摘Accidents caused by spider bites occur in many countries and represent a public health problem due to their high severity and occurrence of fatal accidents. In Veterinary Medicine, the incidence of arachnidism is considered nonexistent in large animals, as their thick skin cannot be pierced, rare in cats and common in dogs, particularly due to their exploratory and curious habit, and the habitats of venomous animals, such as the arachnids, located close to urban areas. The aim of this review is to describe the characteristics and distribution of spiders, the mechanism of action of the venom, clinical signs, diagnosis and treatment of accidents caused by arachnids of genera Loxosceles sp., Phoneutria sp., Latrodectus sp., and suborder Mygalomorphae.
文摘Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13 - 1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.24 - 1.27 g/ml) Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, and 89.3% of lipids presents in the hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids (phosphatidylcholine and phosphatidylethanolamine) and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. In order to confirm the role played by lipoproteic fractions in vitro assays with different 14C-lipid were performed. It was observed that Gr-VHDL takes up mainly free fatty acids and triacylglycerols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three proteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa, and other minority of 249 kDa. In conclusion, this study reports lipid characterization of the lipoproteic fractions present in the hemolymph of the tarantula, G. rosea. The role of each lipoproteic fraction in relation to lipid uptake is sustained by in vitro assays. Similarities and differences are found when it is compared to lipoproteins of only the three species of spiders studied.
