Comparative transcriptomics highlights convergent evolution of energy metabolic pathways in group-living spiders.

Although widely thought to be aggressive, solitary, and potentially cannibalistic, some spider species have evolved group-living behaviors. The distinct transition provides the framework to uncover group-living evolution. Here, we conducted a comparative transcriptomic study and examined patterns of molecular evolution in two independently evolved group-living spiders and twelve solitary species. We report that positively selected genes among group-living spider lineages are significantly enriched in nutrient metabolism and autophagy pathways. We also show that nutrient-related genes of group-living spiders convergently experience amino acid substitutions and accelerated relative evolutionary rates. These results indicate adaptive convergence of nutrient metabolism that may ensure energy supply in group-living spiders. The decelerated evolutionary rate of autophagy-related genes in group-living lineages is consistent with an increased constraint on energy homeostasis as would be required in a group-living environment. Together, the results show that energy metabolic pathways play an important role in the transition to group-living in spiders.

A new record of the spider family Caponiidae from China (Arachnida, Araneae).

The family Caponiidae Simon, 1890 is reported for the first time from China. The total number of the known spider families from China increases to 72 with the addition of this family newly recorded in the present paper. Based on male and female specimens collected from Guangxi, China, Laoponiasaetosa Platnick & Jäger, 2008 is illustrated and a global distribution map is generated.