Licensed Translation 03 | Northern Medaka in Nagano Pond Survey

Translation type: Selected paragraphs from the Japanese abstract translated into English by Aquapedia. NOT the complete article or magazine.

Price: Free to read. Reuse: CC BY 4.0, original authors retain credit.

Japanese title: 長野県信濃町の別荘地内ため池の動物相

Original authors: Hikaru Nakagawa

Journal: Japanese Journal of Conservation Ecology, 2026.

English translation (selected abstract passages):

Small ponds, including those built for irrigation or water retention, provide important habitats for aquatic wildlife. The research team surveyed a pond in Shinanomachi, Nagano Prefecture, once a month from May 2023 to April 2024, excluding January through March. Across the survey they recorded 111 taxa belonging to 51 families and 20 orders. Five fish species were collected, including the critically endangered topmouth gudgeon Pseudorasbora pumila. Among aquatic insects, beetles formed the largest group, followed by true bugs and dragonflies. The authors conclude that the pond plays an important role in maintaining regional biodiversity.

Aquapedia editorial note (not translated source text): The full Japanese article also records Northern Medaka (Oryzias sakaizumii) in the pond; that is a wild species record, not a claim about the origin of a domestic strain.

Adaptation credit: Aquapedia English selection (2026), translated from the cited Japanese abstract with contextual interpretation distinguished above. No original publisher PDF or photographs copied.