Spawning habitat selectivity of Honmoroko, Gnathopogon caerulescens, in lagoon inlets, Lake Biwa, central Japan

Evaluation of genetic diversity in an endangered fish Gnathopogon caerulescens using environmental DNA and its potential use in fish conservation

“…At present, it is listed as a critically endangered species by the Ministry of the Environment, Japan (Ministry of the Environment Japan, 2020) and as an endangered species by the International Union for the Conservation of Nature (Kanao & Hasegawa, 2019). It lives in pelagic habitats in the northern basin (Figure 1) and migrates to lakeshores, lagoons, or inflow rivers from late February to early July for spawning (Fujioka & Saegusa, 2015;Kikko et al, 2020). Eggs are laid on plants or substrates in shallow water near the shore, where a decrease in water level can easily result in the desiccation of eggs (Fujioka, 2013;Kikko et al, 2014).…”

“…Juveniles grow in nursery shores and lagoons during summer and move to pelagic habitats during the fall. As most of the fish return to their natal habitats for spawning (Kikko, 2015(Kikko, , 2020 and then die, their local populations can be genetically differentiated as a result of the drastic decline in population size and the subsequent random genetic drift.…”