Analysis of the Persistence and Particle Size Distributional Shift of Sperm-Derived Environmental DNA to Monitor Jack Mackerel Spawning Activity

Abstract

Environmental DNA (eDNA) analysis holds great promise as an efficient and noninvasive method to monitor not only the distribution of organisms but also their spawning activity. In eDNA analysis-based monitoring of spawning activity, the detection of sperm-derived eDNA is a key point; however, its characteristics and dynamics are completely unknown. The present study focuses on the persistence and particle size distribution (PSD) of eDNA derived from the sperm of Japanese jack mackerel. First, we investigated the time-dependent degradation and the PSD of sperm-derived eDNA by artificially adding sperm to seawater. Next, we kept fish in tanks and examined the changes in eDNA concentration and PSD before and after spawning. The results of two experiments showed that the degradation of sperm-derived eDNA proceeded rapidly, with PSD shifting to a smaller size regardless of the DNA region (Cyt b or ITS1). Additionally, it was shown that the nuclei and mitochondria released from sperm through degradation had a size distribution that was not simply dependent on each organelle size. These results will contribute to elucidating the characteristics and dynamics of eDNA specifically during the spawning season and to further developing eDNA analysis as a powerful tool for the monitoring of spawning activity.

Environmental DNA phylogeography: Successful reconstruction of phylogeographic patterns of multiple fish species from cups of water

“…DNA extraction from filter samples was performed according to two different procedures: the method of Tsuji, Inui, et al (2022) for the 67 sites surveyed between 2017 and 2020; and the method of Tsuji, Murakami, and Masuda (2022) for the 27 sites surveyed in 2021. The two procedures described in Tsuji, Inui, et al (2022) and Tsuji, Murakami, and Masuda (2022) differed slightly in several respects such as the type of column used to infiltrate the filter into the DNA extraction reagent mix, and the total volume and composition ratio of the extraction reagent mix. In both procedures, the DNA was purified using the DNeasy blood tissue kit and finally eluted in 100 μL Buffer AE.…”

Identifying spawning timing and locations of jack mackerel in a semi-closed bay using environmental DNA analysis

“…In recent years, environmental DNA (eDNA) analysis has emerged as a rapidly advancing biodiversity assessment method and has entered a new phase where it can estimate ecological events such as spawning as well as the presence of the target species (Ip et al, 2023; Sato et al, 2021; Tsuji et al, 2022b; Wu et al, 2023). Environmental DNA on macroorganisms refers to generic terms for DNA derived from epidermal tissue, faeces, mucus and other sources released from organisms into their habitat (Barnes and Turner, 2016; Merkes et al, 2014).…”

“…lake, Erickson et al, 2016; Vautier et al, 2023; Wu et al, 2023; river, Bracken et al, 2019; Di Muri et al, 2022; Saito et al, 2022; Tsuji and Shibata, 2023). Previous studies investigating fish which spawn in the sea, such as the Japanese jack mackerel ( Trachurus japonicus ) and the Japanese eel ( Anguilla japonica ), have reported significant increases in eDNA concentrations before and after spawning in both species when artificially spawned in laboratory conditions (Takeuchi et al, 2019; Tsuji et al, 2022b). These findings suggest that spawning surveys based on eDNA could be a valuable method for investigating spawning in saltwater fish.…”

“…In recent years, environmental DNA (eDNA) analysis has emerged as a rapidly advancing biodiversity assessment method and has entered a new phase where it can estimate ecological events such as spawning as well as the presence of the target species (Ip et al, 2023;Sato et al, 2021;Tsuji et al, 2022b;Wu et al, 2023).…”

“…In species that perform in-vitro fertilisation, the reproductive materials such as oocytes, ovarian fluid and sperm released during spawning are also an eDNA source. In eDNA-based spawning surveys, the occurrence of spawning can be identified by observing rapid and significant increases in eDNA concentration and/or changes in nuclear/mitochondrial DNA ratios caused by sperm-derived eDNA (Bylemans et al, 2017;Tsuji et al, 2022b).…”