Adaptation to the hottest spot on earth: Dietary ecology of an enigmatic desert gecko based on DNA metabarcoding

The Lut Desert, southeastern Iran, regularly has the largest contiguous area of surface temperatures above 65°C compared to anywhere else on Earth. Despite these harsh conditions, some specialized species thrive in this extreme habitat. Misonne's spider gecko, Rhinogecko misonnei de Witte, 1973 (Reptilia, Squamata, Gekkonidae) is an endemic species that is native to the central part of the Lut Desert. This research aimed to explore the dietary gut content and ecology of Misonne's spider gecko populations inhabiting the Lut Desert. A DNA metabarcoding approach was applied to obtain data from the stomach content of six collected specimens. A total of 147,451 amplicon reads representing a total of 94 OTU (=Operational Taxonomic Units) for the CO1-5P barcode region were sequenced. Of 94 OTUs, 50 (53.2%) identically matched ≥97% with BOLD and/or NCBI database and were identified at the genus level. Blasting in both databases revealed the presence of three phyla including Chordata (55.23%), Arthropoda (44.72%), and Annelida (0.05). 99.54% of Chordata DNA belonged to Rhinogecko misonnei mainly coming from stomach tissue of the examined specimens. Within the arthropods, 87.64% of the OTUs matched Insecta and 12.08% Arachnida. Our findings indicate that Rhinogecko misonnei is a generalist gecko that feeds on a variety of food items. About 81% of Rhinogecko food items in the central Lut are migratory insects that come from adjacent areas of the Lut District, although the arachnid food items originate from the central Lut. This study emphasizes the importance of the insect fauna of adjacent areas of the Lut Desert for the stability of the Desert food web.