Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies Author Albert, James S. text Zootaxa 2017 2017-08-08 4318 3 401 438 journal article 32158 10.11646/zootaxa.4318.3.1 8d4c68da-48ac-44d9-982b-bb2a13ed886c 1175-5326 887692 2848Cac4-F301-4A47-B6Cd-366051Ad2B5E Gymnotus carapo caatingaensis New Subspecies Figure 3 B, Tables 3 and 4 Holotype : AUM 20624, 225 mm. Brazil , Piauí , Río Gurgueia aff. Río Parnaíba ( 08°32’24”S , 044°25’48”W ). Paratype : AUM 20624, 210 mm. Brazil , Piauí , Río Gurgueia aff. Río Parnaíba ( 08°32’24”S , 044°25’48”W ). Non-Types: AUM 20689 (2), 95–138 mm , Brazil , Piauí , Río Gurgueia , 25 km SW Urucui . AUM 2079 (4), 156–192 mm , Piauí , Parnaíba , between Santa Filomena and Jurumenha . AUM 20793 (4), 111–195 mm , Brazil , Piauí , Parnaíba , between Santa Filomenha and Jurumenha . Description: Specimens of G. carapo from the Caatinga ecoregion in the Brazilian state of Piauí overlap substantially in morphometric and meristic PC-space with specimens from other localities ( Figures 4 , 5 , and 12). Gymnotus carapo caatingaensis is characterized by the following combination of statistically significant (p <0.01) traits when compared to the rest of the species as a whole (see Principal Components Analyses and t-tests): short head (HL 10.2%–12.2% TL, mean 11.2% vs. 10.4%–15.5%, mean 12.7% in all other subspecies), long postorbital distance (PO 63.2%–66.9% HL, mean 65.2% vs. 36.8%–66.5%, mean 61.2% in all other subspecies), long pectoral fins (P1 46.9%–58.0% HL, mean 52.3% vs. 36.3%–60.9%, mean 45.9% in all other subspecies) and short anal fin (AF 70.9%–80.1% TL, mean 75.8% vs. 69.4%–88.0%, mean 79.9% in all other subspecies). Distribution: Known from Río Parnaíba basin in the Brazilian Piauí state of Piauí ( Figure 2 B). Etymology: Subspecific epithet derived from the Caatinga ecoregion of northeastern Brazil , home to a characteristic arid scrubland and thorny scrub forest.