Poeciliopsis gracilis (Heckel 1848) . Porthole Livebearer; Olomina, Alumina, Pepesca, Guatopote Jarocho

Vouchers: UCR 0265-008 (135), 0273-005 (3), 0466-007 (11), 0467-004 (5) and 0473-004 (6); other collections: KU 18698 (1). Distribution: North and Central America; from southern Mexico to northern Nicaragua, Atlantic and Pacific drainages; (Nicaragua) Co (Atlantic), Ne, ER and PN (Pacific); 2–678 masl; Sec, Dia, Amp. Occurrence and conservation status: Nat; LC (2019), population trend unknown. Literature: Astorqui (1975: 112; brief description, including illustrations and an identification key, and information on distribution and ecology), Villa (1982: 135; detailed description, including illustrations and an identification key, and information on distribution and ecology) and Ward et al. (2022: 1; phylogenetic position, species delimitation and revalidation, including information on distribution, with a map). Remarks: Ward et al. (2022), based on molecular data, restricted P. gracilis to México. Poeciliopsis gracilis and P. pleurospilus are morphologically and ecologically similar species which have had a widely debated taxonomic history and geographic distribution. Detailed taxonomic studies, based mainly on morphological data, are necessary in order to supporting or discarding this hypothesis and to rename or not the material identified as P. gracilis collected outside of Mexico.