Environmental DNA from marine rockpools
The sequencing of environmental DNA (eDNA) has emerged as important new tool to study present and past biodiversity allowing for the identification of multiple taxa from the genetic material shed by organisms into the environment. An approach for studying the eDNA is metabarcoding that has been widely applied to the study of aquatic ecosystems biodiversity, and to identify rare, endangered or invasive species. However, eDNA work in aquatic environments has been mostly focused on vertebrate species (84% on fish and amphibians) while invertebrates in coastal environments have received much less attention and the detection of aquatic insects using eDNA is weakly documented.
Our attention will focus on a peculiar aquatic environment, the marine rock-pools commonly found along the Mediterranean coasts. A few insect groups (chiefly Coleoptera and Diptera) are known to live in marine rock-pools, and among them, several species belong to the water beetle family Hydraenidae, genus Ochthebius Leach 1815. Most of the new hydraenid species belonging to the genus Ochthebius recently discovered from southern Europe were found in hypersaline coastal habitats, showing that these aquatic ecosystems is also a potential source of undetected biodiversity. Recent molecular and morphological studies strongly suggested the presence of a series of cryptic and thus far not formally recognized Ochthebius species around Mediterranean basin coasts and particularly along the coasts of Sicily.
Here, we intend to use eDNA as a tool for simultaneous identification of multiple rock-pools beetles species that may be gone undetected by traditional biomonitoring surveys that require observation and physical collection of whole organisms.