Gymnotus carapo subsp. caatingaensis Albert 2017, New Subspecies

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.