Cynodonichthys isthmensis (Garman 1895) (Fig. 9D). Isthmian Rivulus; Olomina, Alumina, Olomina Saltona, Killi, Saltón, Killi del Istmo

Vouchers: UCR 0266-004 (5), 0361-004 (1), 0447-008 (2), 0459-003 (3), 0474-001 (3), 0475-001 (8), 1052-007 (9) and 1058-001 (21); other collections: IBUNAM 13843 (1), 13844 (1), 13845 (1), KU 18700 (1). Distribution: Central America; from southern Honduras to eastern Costa Rica, Atlantic and Pacific drainages; (Nicaragua) Co, UI, WK, Pr, GM, KP, Es, BF, IM, To, Sa, SJ, RF and LN (Atlantic); 15–700 masl; Sec, Pot. Occurrence and conservation status: Nat; LC (2020), population trend unknown. Literature: Astorqui (1975: 156, as Rivulus isthmensis isthmensis —synonym; brief description, including illustrations and an identification key, and information on distribution and ecology), Villa (1982: 143, as R. isthmensis isthmensis —synonym; detailed description, including illustrations and an identification key, and information on distribution and ecology), Bussing (1998: 176, as R. isthmensis isthmensis —synonym; brief description, including illustrations and an identification key, and information on distribution, with a map, and ecology), González-Alemán (2006: 95, as Rivulus hildebrandt (Myers 1927) —misspelled and misidentification; brief description, including an illustration, and information on distribution and ecology), van den Berghe (2015: 37, as Rivulus rubripunctatus (Bussing 1980) —misidentification; listed, including an illustration and information on distribution and ecology) and Angulo (2021: 53; listed, including information on distribution).