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.