Jellyfish biodiversity and distribution patterns in the Xisha Islands revealed by environmental DNA metabarcoding

Samples were collected at 7 stations in Xisha Islands in the South China Sea in September 2023 (111°34′-112°19′ E, 16°26′-17°00′ N); four stations in the Lingyang reef (LYJ1-4), three stations in the Qilianyu Islands (QLY1-3) .  For seawater samples, six replicates of 1 L samples were collected from shallow seawater (depth<30 m) and mesophotic zones (30 m≤depth≤100 m) at 5 different sites (LYJ1-2 and QLY1-3) across the reef (n=120 samples total).

Surface sediment samples from 7 stations were collected by diving. Some samples were lost, resulting in the final acquisition of 117 seawater and 10 sediment samples. eDNA of seawater samples (n=117) was extracted using a Qiagen DNeasy Blood & Tissue Kit according to the experimental protocols. eDNA of sediment samples was extracted using a DNeasy PowerSoil Pro Kit (Qiagen, Hilden, Germany).The eDNA extracted from seawater and sediment samples were dissolved in 80 µL of AE buffer and C6 Solution, respectively, and stored at -20℃.