Jesogammarus (Jesogammarus) acalceolus sp. nov., female (7.3 mm), NSMT-Cr 29004 A peduncular articles 1–3, accessory flagellum, and flagellar articles 1–4 of antenna 1, medial view B peduncular articles 1–5 and flagellar articles 1–3 of antenna 2, medial view C ischium-dactylus of gnathopod 1, medial view D palmar margin of propodus and dactylus of gnathopod 1, medial view, some setae omitted E ischium-dactylus of gnathopod 2, medial view F palmar margin of propodus and dactylus of gnathopod 2, medial view, some setae omitted G–I coxa-ischium of pereopods 5–7, respectively, lateral views J brood plate on gnathopod 2, lateral view K uropod 3, ventral view.

 
 
  Part of: Tomikawa K, Kimura N (2021) On the brink of extinction: a new freshwater amphipod Jesogammarus acalceolus (Anisogammaridae) from Japan. ZooKeys 1065: 81-100. https://doi.org/10.3897/zookeys.1065.71687