Dominance structure and constancy of spiders in the Indian Thar desert

The knowledge about the species of a habitat (both resident and transient/dominant and rare) is a vital step to plan the conservation measures. Being generalist predators, spiders help controlling the population of their prey and maintain ecosystem stability. This makes spiders excellent bio-indicators for assessing the impact of anthropogenic disturbance factors on natural ecosystems (De, Siliwal, Uniyal and Hussain in Trop. Ecol. 63: 1–7, 2021). The aim of this study was to assess the dominance structure and constancy of spiders in three different habitats (Sand dunes, Riparian and Rocky) of the Thar desert. Study was conducted from March 2017 to February 2019 covering all seasons. The eudominant species in sand dunes and rocky desert belonged to the family Thomisidae. These species were Tmarus sp. 1 and Tmarus kotigeharus Tikader, 1963, respectively. There were two eudominants in Riparian habitat (Oecobius putus O. Pickard-Cambridge, 1876 and Menemerus bivittatus (Dufour, 1831)). Through the analysis of constancy of all the species in the Thar desert, it was revealed that three species were constant in all the three habitats. The number of accessory and accidental species was far higher than constant species in all the habitats. The number of accessory and accidental spider species in all habitats was far higher than constants due to the unstability of spider population. Therefore, this study highlights the necessity for conservation of these habitats of the Thar desert.