Fig. 1 in Fig. 4 in Identification of Sexually Dimorphic Genes in Pectoral Fin as Molecular Markers for Assessing the Sex of Japanese Silver Eels (). Author Bisquert-Ribes, Maria Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Catedràtic José Beltrán Martinez, 2, Paterna, 46980, Spain. * Correspondence: E-mail: maria. bisquert @ uv. es (Bisquert-Ribes) E-mail: juan. rueda @ uv. es (Rueda); ferran. palero @ uv. es (Palero); francesc. mezquita @ uv. es (Mesquita-Joanes) maria.bisquert@uv.es Author Rueda, Juan Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Catedràtic José Beltrán Martinez, 2, Paterna, 46980, Spain. * Correspondence: E-mail: maria. bisquert @ uv. es (Bisquert-Ribes) E-mail: juan. rueda @ uv. es (Rueda); ferran. palero @ uv. es (Palero); francesc. mezquita @ uv. es (Mesquita-Joanes) maria.bisquert@uv.es Author Palero, Ferran Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Catedràtic José Beltrán Martinez, 2, Paterna, 46980, Spain. * Correspondence: E-mail: maria. bisquert @ uv. es (Bisquert-Ribes) E-mail: juan. rueda @ uv. es (Rueda); ferran. palero @ uv. es (Palero); francesc. mezquita @ uv. es (Mesquita-Joanes) maria.bisquert@uv.es Author Savatenalinton, Sukonthip Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham 44150, Thailand. E-mail: sukonthip. s @ msu. ac. th (Savatenalinton) sukonthip.s@msu.ac.th Author Mesquita-Joanes, Francesc Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Catedràtic José Beltrán Martinez, 2, Paterna, 46980, Spain. * Correspondence: E-mail: maria. bisquert @ uv. es (Bisquert-Ribes) E-mail: juan. rueda @ uv. es (Rueda); ferran. palero @ uv. es (Palero); francesc. mezquita @ uv. es (Mesquita-Joanes) maria.bisquert@uv.es text Zoological Studies 2023 2023-07-26 62 40 1 24 http://dx.doi.org/10.5281/zenodo.12828106 journal article 10.6620/ZS.2023.62-40 1810-522X PMC10522628 37772165 Keysercypria Karanovic, 2011 Physocypria (partim) Meisch et al., 2019: 87 . Type species: Keysercypria affinis ( Klie, 1933 ) Karanovic 2011 . Diagnosis (modified after Karanovic (2011)) : Carapace in lateral view usually ovate. RV margin tuberculated anteriorly and posteriorly, LV overlapping RV anteriorly. Surface of carapace smooth, sometimes with long-setae. A1 7-segmented, five long natatory setae of A2 reaching beyond tip of terminal claw, outermost seta completely reduced. Penultimate segment of male A2 divided, t2 and t3 setae transformed into sexual bristles. Terminal segment of Md palp extremely elongated (> 5x longer than wide). Terminal segment of Mxl palp squared. Third endite of the Mxl with bristles. Male T 1 with asymmetrical prehensile palps, first segment of right prehensile palp usually with a robust finger-like protrusion. Basal d1-seta of T 2 absent. Terminal segment of T 3 subquadrate, g-seta very short, d2-seta on T 3 absent. CR well-developed, with long sp-seta (longer than half of Gp length). Hemipenis with b-lobe short, pointed distally and shorter than a-lobe; a-lobe elongated, finger-like, thin in its middle length, with a rounded distal end usually wider than the middle part. Zenker organ with seven spine whorls. Other species : K. deformis ( Klie, 1940 ) , K. longiseta ( Klie, 1930 ) , K. schubarti ( Farkas, 1958 ) , K. xanabanica ( Furtos, 1936 ) . Distribution : NT. Remarks : Karanovic (2011) included in Keysercypria nine species previously assigned to Physocypria and Cypria . Meisch et al. (2019) returned these species to their original genera, but Almeida et al. (2023) reestablished the genus with a more restricted diagnosis based mainly on the chaetotaxy of T 2 and T 3 (see discussion). They kept in the genus Keysercypria some species of the Physocypria s.l. group: the type species K. affinis , plus K. deformis and K. schubarti . However, we consider that also two more Physocypria species assigned by Karanovic (2011) to Keysercypria do merit this genus-level distinction ( K. longiseta and K. xanabanica ), mostly because of their hemipenis morphology. Three former Physocypria species ( P. circinata Würdig and Pinto, 1993 , P. sanctaeannae Margalef, 1961 and P. ivanae ( Díaz and Lopretto, 2011 )) assigned to Keysercypria by Karanovic (2011) or by Díaz and Lopretto (2011) are excluded because their hemipenis morphology is not congruent with the others or cannot be confirmed due to lack of males. We decide to maintain C. obtusa and C. pellucida in the genus Cypria because their hemipenes are clearly distinct from Keysercypria affinis ( type species) and because of the absence of RV marginal tubercles, as pointed out by Almeida et al. (2023) .