Japan Fisheries Research and Education Agency

Observation of high proportions of unmated females in kuruma prawn Penaeus japonicus in the Seto Inland Sea: implications for a mate-finding Allee effect

Abstract The abundance of kuruma prawn Penaeus japonicus in Japanese waters has declined markedly since the mid-1990s. Despite this long-term decline, the underlying mechanisms remain poorly understood, limiting the development of effective stock management strategies. One conseq...

Enabling climate action: A nexus approach for delivering co-benefits across biodiversity, water, food, and health

Climate response options rarely affect biodiversity, water, food, and health in uniform ways. This comparative analysis examines why technically viable response options generate uneven cross-nexus outcomes, and how governance and justice conditions shape whether these outcomes be...

The Pacific seaweed pipefish Syngnathus schlegeli exhibits exceptionally high levels of polygynandry among fishes with paternal egg care

Abstract Syngnathid fishes (family Syngnathidae), characterised by male pregnancy via a brood pouch, provide an exceptional model system for studying the relationship between mating systems and sexual selection, as they display extraordinary diversity in both mating systems and s...

Seawater sprinkling promotes swim bladder inflation and reduces lordosis during mass-scale seed production in the leopard coral grouper Plectropomus leopardus

Abstract Lordosis caused by failed swim bladder inflation (SBI) is a major constraint on the production of Plectropomus leopardus . During seed production, an oil film applied to prevent surface trapping impedes air gulping and hinders SBI. We developed a full-surface seawater sp...

Quantifying the direct and indirect costs of reproduction

The energetic costs of reproduction remain incompletely resolved, despite being fundamental to life history theory. Recent work has drawn attention to indirect costs of reproduction and suggested that they may be underestimated in energy budget models. However, a challenge in the...

Mitigating the impacts of oligotrophication and thermal stress on Pacific oyster Magallana gigas aquaculture through solar-powered artificial upwelling

Abstract Recent oligotrophication and rising water temperatures in the Seto Inland Sea of Japan have led to a decline in oyster production in Hiroshima Prefecture. This study developed and evaluated the “Seawater Pump-up Apparatus for Localized Oceanic Warming-mitigation” (SPALOW...

Redox-network reconfiguration inferred from the ln [O 2 ]– E h relationship under mixed-potential conditions in a shallow pond time series

Abstract. Oxidation–reduction potential (Eh) is widely used as an in situ indicator of redox conditions in aquatic environments, and field electrodes typically record a mixed potential generated by multiple concurrent interfacial redox reactions. Beyond a simple Nernstian interpr...

Using drift coefficients as a basis for inferring times, effective population sizes, and genetic adaptations

Genetic drift and gene flow can give rise to a complex population genetic structure. The inverse problem of estimating the genetic drift and gene flow in the past, based on the present-day genomic population structure, can be solved using an admixture graph. This describes the di...

Identity of herbivorous fishes preventing the restoration of Sargassum beds in Nagasaki Prefecture, southwestern Japan

Abstract Despite the widely recognized impact of fish herbivory on macroalgae, few studies have quantified the specific contributions of individual species in Japan. We used visual censuses along belt transects to investigate the abundance of herbivorous fishes, and measured fish...