Environmental DNA dynamics during embryonic development in the rare minnow Gobiocypris rarus

Abstract

Monitoring the timing, location, magnitude of spawning events, and the number of hatched larvae is important for the efficient conservation and management of fish diversity, including rare and threatened species (Fuiman & Werner, 2009;Schiemer et al., 2002). Traditional monitoring methods are time-consuming, labor-intensive, and involve detection biases that may lead to morphological misidentification and miscounts of individuals and/or eggs (Bonar et al., 2009).Reproduction surveys utilizing drift nets, seines, or bottom trawls to capture individuals and/or eggs may disturb habitats and kill fish and their eggs in nests. Alternatively, environmental DNA (eDNA) coupled with quantitative PCR analysis may be used to discern the presence/absence of target species and their relative abundance from water, without capturing the organism (Taberlet et al., 2012;Thomsen & Willerslev, 2015).Knowledge on eDNA dynamics (e.g., origin, release, and decay) during fish developmental stages is fundamental for the development of eDNA methods to monitor fish populations at different life-history stages and to interpret eDNA survey data to inform efficient conservation and management (Lacoursiere-Roussel & Deiner, 2021). Previous studies have investigated the origin and release of eDNA during spawning events in controlled laboratory environments (Bylemans et al., 2017;Tsuji & Shibata, 2020). These