Find research datasets worth reusing

FIGURE 3 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

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 06964, 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 8 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

FIGURE 8. Principal components analysis of point-to-point linear measurements for three sympatric Gymnotus from the eastern Amazon: G. c. orientalis (n=16), G. bahianus (n=28) and G. diamantinensis (n=3). Head length (HL), head depth (HD) and body depth (BD) load heavily on PC1, while body width (BW), preanal length (PA) and postorbital length (PO) and load heavily on PC2. Note the greater separation in PC space than is observed among G. carapo subspecies.

FIGURE 1 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

FIGURE 1. Schematic illustrating how quantitative differences may be used to characterize species and subspecies. A. Diagnostic differences of trait values (such as a linear measurement) between two species, where the difference of mean trait values between species exceeds the within-species variances; AB> LA and LB. B. Similar differences represented in a principal components (PC)-space, using circles instead of bell curves. Note differences between species centroids exceeds within-species variances (AB> PC1A and PC1B). C. Degrees of phenotypic divergence in a multivariate morphospace. Top: two species with minimal overlap (AB> PC1A and PC1B); e.g. sympatric G. carapo and G. ucamara. Middle: two subspecies with substantial overlap but significant differences (AB ~ PC1A and PC1B); e.g. allopatric G. c. occidentalis and G. c. orientalis. Bottom: one species with morphometrically indistinguishable populations (AB

FIGURE 2 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

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 10 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

FIGURE 10. Principal components analysis of four meristic characters for five sympatric Gymnotus species of the southern fauna: G. c. australis (n=2), G. chimarrao (n=4), G. omarorum (n=10), G. sylvius (n=4) and Gymnotus CALA (n=29). The number of pectoral fin rays (P1R) and number of scales above the lateral line at midbody (SAL) load heavily on PC1, while numbers of posterior lateral line rami (PLR) and bands (BND) loads heavily on PC2. Note the greater separation in PC space than is observed among G. carapo subspecies.

FIGURE 17 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

FIGURE 17. Thalweg-constrained dispersal pathways among the geographic centers of G. carapo subspecies ranges. Regional abbreviations as in Figure 5. Note the "prone-8" pathway in the Guianas (Lujan & Armbruster 2011). Note also the Shield Pathways between AU and CT and OR, and the Sub-Andean pathway between AU, MD, OC, and SE (Tagliacollo et al., 2016).

FIGURE 4. Landmarks used for geometric morphometric analyses. Fifteen landmarks were recorded for 88 in Revision of the polytypic electric fish Gymnotus carapo (Gymnotiformes, Teleostei), with descriptions of seven subspecies

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 12 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 12. Gymnotus omarorum with the position of first ventral lateral-line ramus illustrated. A. Gymnotus omarorum holotype, ZVC-P 6480 (254 mm). B. Gymnotus cuia holotype, UFRGS 23700 (193 mm). Note the posterior position of first ventral lateral-line ramus relative to G. omarorum. C. Gymnotus carapo australis (MLP 11222, 289 mm). Note, again, the posterior position of first ventral lateral-line ramus relative to G. omarorum.

FIGURE 7 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 7. Variation within the type series of Gymnotus cuia. A. The holotype, UFRGS 23700 (193 mm). B. Four specimens of the paratype series, UFRGS 9794 (171–217 mm).

FIGURE 15 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 15. Guide to the differentiation of the Gymnotus tigre and G. carapo clades on the basis of readily-apparent morphological traits (ventral lateral line ramus shape, shape of scales on anterior portion of the body and coloration of anal fin). A. Gymnotus inaequilabiatus, MCP 6956 (683 mm). B. Posterior body region of G. inaequilabiatus and G. c. australis. Note shorter, straight VLRs in G. inaequilabiatus and longer, curved VLRs in G. c. australis. C. Scales removed from posterior body regions (at about two-thirds TL, first scale row above lateral line) of G. inaequilabiatus and G. c. australis. Note the smaller and axially-elongate scales of G. inaequilabiatus. and larger, ovoid scales of G. c. australis. D. Caudal body regions of G. inaequilabiatus and G. c. australis. Note pigment speckles arranged in broken stripes on the anal-fin membrane of G. inaequilabiatus, and darkly pigmented anal-fin membrane of G. c. australis.

FIGURE 2 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 2. Geographic distributions of the materials examined from two species of the G. tigre clade of the southern Neotropics. Specimens from all localities were personally examined and identified by the authors.

FIGURE 10 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 10. Characterization of the electric organ discharges of Gymnotus carapo australis and Gymnotus cuia. A. Head-totail recorded EOD waveforms for Gymnotus carapo australis (black) and Gymnotus cuia (red) from Rio Grande do Sul, Brazil. Note the invariable presence of the P-1 and P3 phases in the waveform in G. carapo australis but not G. cuia. B. Power spectral density (PSD) plots for Gymnotus carapo australis (black) and Gymnotus cuia (red) from Rio Grande do Sul, Brazil. Note the higher peak power frequency in G. carapo australis.

FIGURE 5 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 5. Principal components analysis of 15 geometric morphometric landmarks comparing the G. cuia to G. c. australis and G. omarorum. A. Principal component one explains 25.7% of the variance and PC2 explains 20.7% of the variance in the comparison between G. c. australis (n=5) and G. cuia (n=29). Note the relatively large separation in shapespace between species. B. Principal component one explains 24.4% of the variance and PC2 explains 16.6% of the variance in the comparison between G. omarorum (n=10) and G. cuia (n=29).

FIGURE 9 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 9. Habitat and live appearance of G. cuia. A. The type locality of G. cuia, Lagoa Verde, Itapuã State Park, Viamão, Rio Grande, do Sul, Brazil (30°22'52"S, 051°01'25"W). Photo: Diego Cognato. B. Close-up photo of the head of a live G. cuia. Photo: Will Crampton. C. Full-body photo of of a live G. cuia. Photo: Will Crampton.

FIGURE 4 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 4. Principal components analysis of 10 morphometric and eight meristic characters comparing G. omarorum (red) and G. cuia (blue). A. Principal component one explains 33.1% of the variance and PC2 explains 15.5% of the variance in the comparison between G. omarorum (n=12) and G. cuia (n=56). Note the separation in shapespace between species. B. Principal component one explains 41.4% of the variance and PC2 explains 27.1% of the variance in the comparison between G. omarorum (n=12) and G. cuia (n=45). Note the relatively large separation in shapespace between species.

FIGURE 3 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 3. Principal components analysis of 10 morphometric and eight meristic characters comparing G. c. australis (red) and G. cuia (blue). A. Principal component one explains 43.2% of the variance and PC2 explains 14.2% of the variance in the comparison between G. c. australis (n=28) and G. cuia (n=56). Note the relatively large separation in shapespace between species. B. Principal component one explains 49.9% of the variance and PC2 explains 17.8% of the variance in the comparison between G. c. australis (n=28) and G. cuia (n=45). Note the relatively large separation in shapespace between species.

FIGURE 8 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 8. Scatterplots of the variation on salient characters separating G. cuia and G. c. australis. A. Head length (%TL) vs. total length (mm). B. Body depth (%HL) vs. head length (mm). C. Head depth (%HL) vs. head length (mm).

FIGURE 1 in Revision of Banded Knifefishes of the Gymnotus carapo and G. tigre clades (Gymnotidae Gymnotiformes) from the Southern Neotropics

FIGURE 1. Geographic distributions of the materials examined from six species of the G. carapo clade clade of the southern Neotropics including the new species G. cuia. White star indicates the type locality for G. cuia. Note G. cf. carapo from Rio de Janeiro could not be positively identified due to age (collected 1865) and condition. Specimens from all localities were personally examined and identified by the authors.

opennotspecifiedApr 2018View details →

FIGURE 7 in Revision of Gymnotus (Gymnotiformes: Gymnotidae) from the Upper Madeira Basin of Bolivia and Peru, with descriptions of two new species

FIGURE 7. Electric organ discharge (EOD) of Gymnotus riberalta males (blue) and females (red). A. Head-to-tail recorded EOD waveforms. B. Accompanying power spectral density (PSD) plot. Note the absence of sexual dimorphism in the EOD waveform.