Gymnotus carapo carapo, Albert, 2017

Albert, James S., 2017, Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies, Zootaxa 4318 (3), pp. 401-438 : 427-428

Gymnotus carapo carapo New Subspecies

Figure 3 C, Tables 3 and 4

Syntypes: NRM 64 (1), 262 mm; NRM 8224 (1), 331 mm; UUZM Linn. coll. 56 (1), 293 mm. Collected in the first half of the 18th Century near Paramaribo, Suriname (Lönnberg 1896:23; Fernholm & Wheeler 1983:216–217; Wheeler 1991:162–163, fig. 6).

Non-Types: MCZ 31219 (1), 262 mm, Suriname (exact locality unknown) . UMMZ 190414, 260 mm, Suriname, Brokopondo, Suriname River, Tapeoeripa creek near Brokopondo village (05°04’N, 054°58’W) . UMMZ 190414 (5), 71–214 mm, Suriname, Brokopondo, Suriname River, Tapeoeripa creek near. Brokopondo village (05°04’N, 054°58’W) . USNM 225274 (8), 81–318 mm, Suriname, Nickerie, Lucie River, upstream of Amotopo-Camp Geologie Rd. (03°36’N, 57°37’W) . USNM 225275 (11), 81–270 mm, Suriname, Nickerie, Corantijn River , 350 m downstream from Wilhelm II falls (03°34’N, 057°15’W) . USNM 225276 (16), 75–148 mm, Suriname, Nickerie, Corantijn River, Dalbana Creek, ca. 3 km upstream from Amotopo–Camp Geologie Rd. (04°20’N, 057°37’W) . USNM 225284 (10), 54–143 mm, Suriname, Nickerie, Corantijn River, Lana Creek , ca. 4 km from intersection with W. Corantijn River (05°28’N, 057°15’W) . USNM 225285 (12), 85–257 mm, Suriname, Nickerie, Corantijn River, creek south of Matapi, approx. 2 km downstream of Cow Falls (04°59’N, 057°38’W) . USNM 225286 (15), 80–319 mm, Suriname, Nickerie, Corantijn River, Koekwie creek (05°31’N, 057°10’W) . USNM 225290 (19), 14–157 mm, Suriname, Nickerie, Corantijn River, Dalibane Creek , Camp Dacclemmen (05°34’N, 057°11’W) . USNM 225297 (14), 53–137 mm, Suriname, Nickerie, Corantijn River, stream on S. side Lucie River (03°35’N, 057°39’W) . UF 180165 (6), 185–337 mm, Suriname, Para, Kola Kreek aff. Para River (05°27’8.820”N, 055°14’42.060”W) . UF 180169 (5), 182–340 mm, Suriname, Brokopondo, Marshall Kreek, aff. Suriname River (05°14’24.9”N, 055°05’58.6”W) . UF 180173 (11), 34–72 mm; UF 180175 (2), 65–219 mm, Suriname, Marowijne, Cottica Rivier, aff. Commewijne River (05°35.21’N, 054°17.11’W) .

Description: Specimens of G. carapo from Suriname overlap substantially in morphometric and meristic PCspace with specimens from other localities ( Figures 4 , 5 , and 12). Gymnotus carapo carapo 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): long preorbital distance (PR 31.4%–40.2% HL, mean 36.3% vs. 28.0%–39.4%, mean 34.6% in all other subspecies) and wide mouth (MW 33.6%–47.6% HL, mean 43.0% vs. 32.2%–49.0%, mean 40.2% in all other subspecies).

Distribution: Known from Atlantic coastal drainages of Suriname and French Guiana, including the Brokopondo, Nickerie, and Suriname districts of Suriname in the Lucie, Suriname, and Corantijn rivers, and all departments of French Guiana ( Figure 2 B).

Etymology: Subspecific epithet derived from the specific epithet.

Figures

FIGURE 2. Geographic distribution of Gymnotus carapo. A. Closed circles show 111 localities of specimens used in morphometric analyses, and open circles show 191 other verified G. carapo localities. B. Collection localities color coded by subspecies. Note G. carapo is absent from the interior of the Brazilian shield and the Atlantic coast of Brazil from Ceará to Rio Grande do Sul.

FIGURE 3. Specimens illustrating variation in body shape and color pattern among seven subspecies of Gymnotus carapo A. G. c. australis, MLP 11222, 289 mm, Argentina, Misiones province, Río Iguazú basin, Arroyo Verde (25 ° 40 ’ 15 ” S, 053 ° 56 ’ 00.8 ” W); B. G. c. caatingaensis, AUM 20624, 225 mm. Brazil, Piauí, Río Gurgueia aff. Río Parnaíba (08 ° 32 ’ 24 ” S, 044 ° 25 ’ 48 ” W); C. G. c. carapo, UMMZ 190414, 146 mm. Suriname, Brokopondo, Marshal Kreek, aff. Suriname River (05 ° 14 ’ 24.9 ” N, 055 ° 05 ’ 58.6 ” W); D. G. c. madeirensis, UMSS 0 6964, 178 mm. Brazil, Amazonas, Río Beni (10 ° 51 ’ 44.302 ” S, 066 ° 04 ’ 50.300 ” W); E. G. c. occidentalis, UF 122820, 279 mm. Peru, Loreto, Iquitos (03 ° 43 ’ 51.73 ” S, 073 ° 15 ’ 3.83 ” W); F. G. c. orientalis, MCZ 45189, 165 mm. Brazil, Para, Parauapebas, Río Arari, Ilha de Marajó (01 ° 01 ’ S, 048 ° 58 ’ W); G. G. c. septentrionalis, ROM 83885, 233 mm. Guyana, Essequibo, Río Mazaruni (04 ° 55 ’ 33.208 ” N, 060 ° 36 ’ 53.784 ” W). Scale bars = 10 mm.

FIGURE 4. Landmarks used for geometric morphometric analyses. Fifteen landmarks were recorded for 88 morphologically mature specimens from seven subspecies of G. carapo Landmarks: 1) tip of snout; 2) tip of maxilla; 3) margin of maxilla; 4) external naris; 5) second pore of the supraorbital laterosensory canal; 6) point directly above midline of eye; 7) supraoccipital crest; 8) base of first anal fin ray; 9) anus; 10) seventh pore of the posterior marginal laterosensory canal; 11) anterior margin of eye; 12) posterior margin of eye; 13) top of preopercle; 14) top of opercle; 15) base of most ventral pectoral fin ray.

FIGURE 5. Principal components analysis of linear measurements for 175 specimens from seven subspecies of G. carapo: G. c. australis (AU, n = 25), G. c. caatingaensis (CT, n = 8), G. c. carapo (CA, n = 31), G. c. madeirensis (MD, n = 13), G. c. occidentalis (OC, n = 65), G. c. orientalis (OR, n = 16) and G. c. septentrionalis (SE, n = 15). Head length, head depth, body width and body depth load heavily on PC 1, while pre- and postorbital (PR and PO, respectively) and preanal (PA) lengths load heavily on PC 2. Note the substantial overlap in PC space between subspecies.