Gephyrocharax intermedius Meek & Hildebrand, 1916

Vanegas-Ríos, James A., 2016, Taxonomic review of the Neotropical genus Gephyrocharax Eigenmann, 1912 (Characiformes, Characidae, Stevardiinae), Zootaxa 4100 (1) : 30-38

Gephyrocharax intermedius Meek & Hildebrand, 1916

( Figs. 14–16 )

Gephyrocharax intermedius Meek & Hildebrand, 1916: 221 , 224, 277–279 [original description, paratypes not mentioned, holotype FMNH 8945, type locality: “Rio Chame, Panama ” (= Panama: Chame River)]. Eigenmann, 1920b: 15 [listed]. Eigenmann, 1922: 156 [catalogue]. Myers in Eigenmann & Myers, 1929: 477, 483 [redescribed, figures not cited]. Hildebrand, 1938: 253 –254 [data on type locality, morphological comments]. Schultz, 1944: 323 [key]. Dahl & Medem, 1964: 65 [compared with G. s i n u e n s i s]. Bussing, 1974: 139 –140 [compared with Pterobrycon myrnae , examined material]. Weitzman & Fink, 1985: 103 [examined material, comments on type locality]. Vari & Howe, 1991: 21 [comments on type material]. Burns, Weitzman, Grier & Menezes, 1995: 133 –135 [spermatozoid morphology, evidence of insemination]. Weitzman, 2003: 224 [catalogue]. Burns, Quagio-Grassiotto & Jamieson, 2009: 329 [details on spermatozoids]. Bonilla- Rivero & López-Rojas, 2013: 489, fig. 1 [distribution map]. Vanegas-Ríos, Azpelicueta, Mirande, Gonzales, 2013: 282 [examined material]. Thomaz, Arcila, Ortí & Malabarba, 2015: 5, 10, table 2, fig. 5, Add. Files 2, 5 [comments on insemination strategy and sperm morphology, phylogenetic relationships, placed in Stevardiinae , Stevardiini, sampled specimens].

Gephyrocharax whaleri Hildebrand, 1938: 231 , 252, 254–256, fig. 2 [original description, paratypes without catalogue numbers, holotype USNM 106513, type locality: “Rio Chame or a near-by stream, Pacific slope, Panama ” (label in jar, Panama: streams crossed by highway between Campana and La Venta, R. P.)]. Schultz, 1944: 323 [key]. Miller, 1966: 137 [listed from Pacific coastal drainages in Panama, data compilation]. Weitzman & Fink, 1985: 103 [examined material, comments on type locality]. Vari & Howe, 1991: 22 [comments on type locality and paratypes]. Weitzman, 2003: 225 [catalogue]. Bonilla-Rivero & López-Rojas, 2013: 489, fig. 1 [distribution map]. Vanegas-Ríos, Azpelicueta, Mirande, Gonzales, 2013: 283 [examined material]. Thomaz, Arcila, Ortí & Malabarba, 2015: Add. File 5 [tentative classification]. [new synonym].

Diagnosis. Gephyrocharax intermedius differs from its congeners by the proximal third of the outer caudal-fin rays unpigmented or whitish (vs. proximal third pigmented by dark chromatophores), the absence of gill gland in adult males (in 82 specimens of 87 examined) (vs. presence of gill gland), and the first ventral procurrent ray of adult males concave and associated to a strong sagittal expansion on the distal portion of the second ventral procurrent caudal-fin ray (vs. first ventral procurrent ray straight or slightly concave, and weakly expanded sagittally, except in G. atracaudatus ). The species is also distinguished from almost all its congeners by the reduced or absent lobe on the posteroventral margin of the pouch scale in adult males (vs. this lobe present and well developed, except in G. atracaudatus and G. major ). The possession of a terminal lateral line tube between caudal-fin rays 10 and 11 (vs. absence of this tube) differentiates G. intermedius from G. melanocheir , G. t o r re s i, and G. v a l e n ci a. The species further differs from G. martae by the snout to pectoral-fin length (25.4–31.3 % SL vs. 20.7 % SL) and from G. caucanus by the number of lateral-line scales (36–41 vs. 42–47), number of branched anal-fin rays (24–29 vs. 29– 36), and number of vertebrae (37–39 vs. 41–42).

Description. Morphometric data in Table 4 . Largest male 61.1 mm SL, largest female 56.4 mm SL. Body laterally compressed, with maximum depth at vertical through pelvic-fin origin or slightly anterior to this point. Dorsal profile of head slightly convex from margin of upper lip to posterior tip of premaxilla, straight or somewhat convex from this point to tip of supraoccipital spine. Dorsal profile of body somewhat convex from tip of supraoccipital spine to dorsal-fin origin, slanting posteroventrally along dorsal-fin base, and straight from posteriormost dorsal-fin ray to caudal peduncle ( Fig. 14 ). Ventral profile of body convex from tip of dentary to vertical through distal half of pectoral fin, slightly convex from this point to anal-fin origin, straight and slanting posterodorsally and (or sometimes slightly concave) from this point to caudal peduncle origin. Anterior fontanel intraspecifically variable in adults (variation not associated to any population); absent, reduced to medium-sized opening anterior to epiphyseal bar, or completely developed being bordered anteriorly by mesethmoid. Anterior nostril rounded, separated by skin fold from larger posterior nostril. Groove with at least three rows of neuromasts extending from half-length between posterior pore of nasal bone and nostrils to posterior portion of frontals. Small groove with few neuromasts between nostrils and nasal bones.

Characters (A) (B) Males Females and unsexed juveniles ......continued on the next page

Characters (A) (B) Males Females and unsexed juveniles Mouth superior, lower jaw projecting slightly anterior to tip of upper jaw. Premaxilla with two rows of teeth. Outer row with 2 (2), 3 (54), 4* (124), 5** (20), or 6 (2) teeth; usually tricuspid, rarely bi- or tetracuspid teeth. Inner row with 4 (43), 5* (157), or 6 (2) teeth; symphyseal tooth tetracuspid and remaining teeth pentacuspid, posteriormost tooth rarely bi- to tetracuspid. Maxilla with 1 (30), 2 (78), 3* (76), 4 (15), or 5 (2) teeth; usually trito pentacuspid, rarely conical or bicuspid (anteriormost tooth with higher number of cusps) ( Fig. 15 A). Maxilla posteriorly reaching vertical through anterior one-third of eye. Dentary with 9 (7), 10 (24), 11 (34), 12 (55), 13** (47), 14 (15), 15 (12), or 16 (2) teeth; three anteriormost teeth larger, pentacuspid, followed by one median-sized tooth usually bi- or tricuspid, and 5 (7), 6 (24), 7 (34), 8 (55), 9** (47), 10 (15), 11 (12), or 12 (2) smaller conical, tri- or tetracuspid teeth ( Fig. 15 B).

Dorsal-fin rays ii,7 (17) or 8* (185). Nine* proximal pterygiophores on dorsal fin (6 rad, 8 c&s, 3 dissected). Dorsal-fin origin located at vertical between anal-fin rays 5–11. Adipose-fin origin located at vertical through base of posteriormost anal-fin rays or caudal peduncle origin, atypically absent in two. Anal-fin rays iv* (126), v** (77), or vi (3), 24 (12), 25 (27), 26* (55), 27 (73), 28** (29), 29 (6), or 30 (3). Twenty-seven* to 29** proximal pterygiophores on anal fin (6 rad, 8 c&s, 3 dissected). Anal-fin origin closer to origin of hypural joint than to snout tip. Pectoral-fin rays i,8 (6), 9* (120), 10 (68), or 11 (11). Pectoral-fin distal tip posteriorly reaching one-sixth to three-quarters of pelvic-fin length. Pelvic-fin rays i,6 (4) or 7* (197) (one atypical specimen with 8 branched rays). Pelvic-fin origin located at vertical between pored lateral-line scales 8–10 and slightly anterior to body midlength. Caudal fin forked with 10/9 principal rays in all specimens.

Scales cycloid, with variable number of radii along posterior margin. Lateral line complete, pored scales 36 (2), 37 (23), 38 (41), 39 (51), 40* (58), 41 (20), or 42 (8) ( Fig. 6 ). Terminal lateral-line tube present. Predorsal scales 16 (1), 17 (78), 18** (75), 19 (35), 20* (20), 21 (2), or 22 (1). Scale rows between dorsal fin and lateral line 5 (1), 6* (145), or 7** (56). Scale rows between lateral line and anal fin 4 (1), 5* (191), or 6 (12). Scale rows between lateral line and pelvic fin 4 (12), 5* (191), or 6 (1). Circumpeduncular scales 15 (90), 16* (87), or 17 (15).

One or two rows of scales forming sheath along anal-fin base; main ventral row with 11 (1), 12 (1), 13 (3), 14 (11), 15** (32), 16 (16), 17 (42), 18 (17), 19 (18), 20 (10), 21 (3), 22 (2), or 23 (1) scales. Total number of vertebrae 37 (3), 38* (11), or 39 (3); 15* (10) or 16 (4) precaudal and 22 (7), 23* (6), or 24 (1) caudal (6 rad, 8 c&s, 3 dissected). Gill-rakers on dorsal limb of first branchial arch 5* (18), 6 (134), or 7** (36); ventral limb with 10 (3), 11* (94), 12* (79), 13** (10), or 14 (1).

Color in alcohol. Ground color pale yellowish or dark brown, darker along mid-dorsal line and slightly lighter ventrally. Minute dark chromatophores scattered over body, less numerous on lateral and ventral regions of abdomen and ventral region of caudal peduncle. Dark midlateral stripe diffuse, extending from posterior region of humeral blotch to end of caudal peduncle. Dark chromatophores present along myosepta between lateral line and upper portion of anal fin. Dark humeral blotch vertically elongate. Large dark blotch on caudal peduncle, extending from its central region to interradialis muscles; more intensely pigmented posteriorly than anteriorly, higher than wider. Dorsal fin light gray, faintly darkened by chromatophores concentrated on margins of rays and membranes. Anal fin light gray, faintly darkened by chromatophores mainly located on interradial membranes. Ground color of caudal fin light gray; proximal third and especially outer portions vertically unpigmented or whitish posterior to caudal peduncle blotch, posterior portion of fin somewhat darkened by chromatophores on rays and membranes. Pectoral and pelvic fins light gray, with scattered dark chromatophores on rays. Head darker dorsally than ventrally. Few scattered dark chromatophores on opercle and infraorbitals. Premaxilla, anterior portion of maxilla, dentary, and lips with concentrated dark chromatophores. Variations in color pattern between males and females described under sexual dimorphism.

Sexual dimorphism. Males with bony hooks on anal-, caudal-, dorsal- (exceptionally), and pelvic-fin rays. Caudal fin with short, slender, anterodorsally oriented hooks, especially on branched portions of rays 15–17, rarely 13 ( Fig. 15 C). Pelvic-fin rays (except innermost ray) with short, slender, anteroventrally oriented hooks on nearly entire length of rays, occasionally reduced in number or absent on first ray; hooks usually paired or one per segment. Anal fin with slender, anterodorsally or anterolaterally placed hooks with broad bases; from two to 38 pairs per ray located from posteriormost unbranched ray and up to ten anterior branched rays, larger hooks on middle rays. Dorsal fin having two to five pairs of tiny, anterolaterally oriented hooks on posterior margin of posterior branch of anteriormost two branched rays (one specimen, STRI 1205). In adult males, anteriormost unbranched anal-fin ray and 18 to 25 anterior branched rays longer than remaining rays, resulting in convex-shaped margin. In females, anal-fin rays gradually decreasing in length from anteriormost branched ray to posteriormost branched ray; anal-fin margin straight or slightly concave. Anal-fin base of adult males concave or curved along its midlength, this base straight in females. Adult females without externally developed urogenital papillae.

Caudal fin region covered by pouch scale in males less pigmented than in females. Anal fin of males with more concentrated chromatophores on rays having bony hooks than on remaining rays. Mature males with hypertrophied scale forming pouch on lower caudal-fin lobe and with ventral procurrent rays 2 and 3 forming spur-shaped structure. Scarce small aggregations of apparent glandular tissue located on caudal-fin rays and medially to pouch scale. First ventral procurrent ray with strong concavity on its ventral margin ( Fig. 15 C). Second ventral procurrent ray slightly longer than third ray, reaching posteriorly midlength of first ventral procurrent ray, and strongly flattened in sagittal plane. Posterior portion of third ventral procurrent ray more developed laterally than sagittally. Pouch scale with 11–23 radii, usually located between caudal-fin ray 16 and second ventral procurrent ray. Posteroventral pouch-scale lobe reduced or absent ( Figs. 15 C–D). Dorsal surface of pouch scale attached via soft tissue (apparently connective) to caudal-fin rays 10 or 11 to 14. Posterior margin of pouch scale between caudal-fin ray 16 and second ventral procurrent ray. Four scales in vertical series situated ventral to terminal lateral-line scale, overlapping posterior portion of pouch scale. Dorsalmost scale of vertical series sometimes with minute, medial spiny patch oriented toward dorsal margin of pouch scale. Anterodorsal margin of pouch scale usually with small notch. Females with large scale with 17 (3), 18 (2), 19 (2), 20 (8), 21 (8), 22 (8), 23 (5), 24 (1), 25 (3), or 26 (3) radii on lower caudal-fin lobe.

Sexually dimorphic males usually without gill gland (82 specimens), only five males with gland formed by 2 (1), 5 (2), 6 (1), or 7 (1) anteriorly fused gill filaments of ventral limb of first gill arch. Total number of ventral limb gill filaments 24 (1), 25 (2), or 27 (1). Gill-gland length 0.7–2.8 % SL (mean = 1.7 % SL). Columnar glandular cells not found in three branchial arches of mature males analyzed histologically. Regression comparisons of morphometric data by sex with major differences in pectoral fin to pelvic fin length (higher values in females than in males) and caudal-fin depth (higher values in males than in females), but larger specimens not completely separating on SL axis.

Distribution. Gephyrocharax intermedius is distributed along numerous coastal drainages of the Pacific and Caribbean versants between the Canal Zone of Panama and the Gulf of Chiriqui ( Fig. 1 ).

Remarks. Meek & Hildebrand (1916) did not designate the paratype specimens accompanied by their catalogue numbers in the original description of G. intermedius , although it was clear that the study was based on more than one specimen, 64 according to the authors. In the case of G. w h a l er i, it was described by Hildebrand (1938) based on 50 paratypes also with no indication of catalogue numbers. More recently, those catalogue numbers for G. intermedius and G. w h a l er i were listed in the catalogues of type specimens from FMNH ( Ibarra & Stewart 1987) and USNM ( Vari & Howe 1991).

Meek & Hildebrand (1916) described G. intermedius without specification of the collecting dates of the type series. According to the expedition itinerary recorded by them (1916: 217) and Hildebrand’s comments (1938: 254), the collecting dates for the material should be between January and May of 1911.

The type locality of G. intermedius was established as the Chame River by Meek & Hildebrand (1916). In the case of G. whaleri , the precise drainage for the holotype was not specified by Hildebrand (1938) due to the uncertainty on the collecting site. As part of the description of G. w h a l e r i, Hildebrand (1938) stated that on March 10th, 1937, while he was travelling through the route from Balboa to La Venta in Panama, several stops were made for the purpose of collecting specimens in a half-dozen or more small coastal streams crossing the National Highway between Campana and La Venta (near of the Chame River). The author also indicated that specimens (n = 23) from different streams were not preserved as separate collections, and thus, the exact drainage could not be stated. Consequently, Hildebrand (1938) used the Chame River or nearby stream as the type locality of G. whaleri .

Gephyrocharax whaleri is herein proposed as junior synonym of G. intermedius based on the results of several morphological comparisons. Hildebrand (1938: 256) distinguished G. whaleri from G. intermedius by its more vertical mouth which is aligned with the dorsal profile of head (vs. mouth less vertical, not aligned with this profile), the upper lip of snout more developed (vs. upper lip less developed), the dorsal fin reaching or surpassing posteriorly (when deflected) the adipose-fin origin (vs. dorsal fin not reaching posteriorly the adipose-fin origin), and the proportion of the pectoral-fin length in body (3.6–4.1 in SL vs. 4–4.5 in SL). The first two characteristics present considerable variation among the examined specimens from either the type series of both species or other localities. Comparatively, the posterior extent of the dorsal fin was slightly less variable than these two features among the examined specimens, however, it was not observed as invariable as was informed by Hildebrand (1938) for the type series of G. w h a l e r i. The dorsal-fin posterior extent is indeed rather variable, but not distinctive groups can be identified. The meristic and morphometric data of the type series of G. intermedius and G. w h a l er i overlap and do not allow the recognition of both nominal species as different taxa. The SPCA of morphometric data comparing the type specimens of these species did not show differences allowing the distinction of separate groups along the components ( Figs. 16 A–B). Furthermore, the examination of myological and osteological characters failed to point out possible distinguishing characters between the two nominal species. According to the priority principle, the valid name for the species is G. intermedius ( ICZN 1999: articles 23.1 and 23.3).

The SPCA of the morphometric data comparing many specimens of G. intermedius grouped by geographic proximity or basins (Chame, Chiriqui, Cocle del Norte, San Pablo and Santa Maria rivers basins) did not discriminate the groups ( Fig. 16 C–D). This morphometric overlap agreed with the great similarity found in the coloration of body, meristic, osteological and myological data. Consequently, G. intermedius has a widespread distribution across Panama.

Material examined. All specimens from Panama: ANSP 99885, 10, 34.4–39.1 mm SL (2 c&s 37.4– 35.63 mm SL), Chiriquí, Esti River about 1 mile N of Gualaca, approximately 8°32'51.28"N 82°17'59.84"W 128 m a. s. l. ANSP 99856 (previously USNM 233631), 10, 30.9–38.2 mm SL, Coclé, creek about 3 miles of Hato River at the bridge on Interamerican highway, approximately 8°23'17.65"N 80°12'51.69"W 30 m a. s. l. ANSP 104176 (previously USNM 249234), 10, 19.3–25.4 mm SL, Los Santos, Tonosi River at the bridge about center between El Llano de Piedra and the floodplain of Tonosi, approximately 7°26'59.89"N 80°31'1.67"W 49 m a. s. l. ANSP 104236, 10, 21.7–33.0 mm SL, Panama, Cotón River, at the bridge on Interamericana highway about 5 miles W of San Carlos, approximately 8°26'52.41"N 80°1'31.38"W 38 m a. s. l. ANSP 104254, 8, 30.7–38.4 mm SL, Los Santos, Estibana River at the bridge slightly before entrance to Macaracas, approximately 7°44'48.25"N 80°31'53.08"W 72 m a. s. l. ANSP 104434, 20, 22.7–39.0 mm SL (2 ds 35.4–36.6 mm SL), Veraguas, creek at the bridge about 12 miles W of Santiago on Soná highway, approximately 8°3'22.19"N 81°6'34.40"W 34 m a. s. l. AUM 28580, 39, 18.5–39.0 mm SL, Veraguas, Gulf of Parita system, tributary of Santa María River, 4 km from San Francisco across San Francisco-Santiago highway, approximately 8°10'54.59"N 80°57'5.46"W 62 m a. s. l. AUM 31533, 12, 21.7–34.6 mm SL, Coclé, Gulf of Parita, Antón River, Pan-American highway just E of Antón, approximately 8°23'58.20"N 80°15'30.78"W 25 m a. s. l. AUM 31677, 15, 32.5–39.1 mm SL, Chiriquí, Chiriquí- Guayabal rivers system, Grande creek about 9.5 miles NE of David on Las Lomas-Dolega highway, 8°28'0.62"N 82°22'32.71"W 70 m a. s. l. AUM 31712, 37, 15.0– 41.1 mm SL, Herrera, La Villa River basin, Pesé River, 2 km S of Pesé, 7°53'46.00"N 80°36'0.99"W 61 m a. s. l. AUM 32124, 17, 15.8–34.7 mm SL, Herrera, Gulf of Parita, Parita River 5.5 Km NNW Pesé, 7°54'35.06"N 80°38'57.24"W 63 m a. s. l. CAS 44280, 2 paratypes, 31.7– 30.7 mm SL, Panama, Chame River, approximately 8°34'24.59"N 79°53'14.83"W 15 m a. s. l. [Jan to Mar 1911]. FMNH 8945*, holotype of Gephyrocharax intermedius , 44.2 mm SL (rad), male, Panama, Chame River, approximately 8°34'24.59"N 79°53'14.83"W 15 m a. s. l, [Jan to Mar 1911]. FMNH 12511*, 1 paratype, 41.9 mm SL, Panama, Chame River, approximately 8°34'24.59"N 79°53'14.83"W 15 m a. s. l. [Jan to Mar 1911]. FMNH 12512*, 1 paratype, 39.1 mm SL, Panama, Chame River, approximately 8°34'24.59"N 79°53'14.83"W 15 m a. s. l. [Jan to Mar 1911]. FMNH 36760*, 1 paratype, 61.1 mm SL, Panama, Chame River, several small streams crossed by national highway between Campana and La Venta, approximately between 8°43'29.20"N 79°53'8.29"W 139 m a. s. l. and 8°27'43.85"N 79°58'33.37"W 43 m a. s. l. [10 Mar 1937]. FMNH 36761*, 1 paratype, 56.4 mm SL, Panama, Chame River, several small streams crossed by national highway between Campana and La Venta, approximately between 8°43'29.20"N 79°53'8.29"W 139 m a. s. l. and 8°27'43.85"N 79°58'33.37"W 43 m a. s. l.

[10 Mar. 1937]. INHS 53206, 6, 14.5–26.8 mm SL, Coclé, Coclé del Sur River, 1 km S of La Pintada, 8°34'03''N 80°25'58''W approximately 58 m a. s. l. INHS 53216, 10, 35.5–40.3 mm SL, Chiriquí, Chiriquí River, 3 km E Guayaba, 8°26'13''N 82°19'08''W approximately 32 m a. s. l. LACM 56203.003, 2, 24.9–25.0 mm SL, Coclé, Grande River on highway 1 at the bridge and above 20 km SW of Penonomé, 8°25'0''N 80°30'0''W approximately 18 m a. s. l. LACM 56202.004, 2, 24.7–28.9 mm SL, Coclé, Chorrera River, at highway 1 at the bridge, approximately 8 km SSE of Penonomé, 8°26'29.00"N 80°18'57.00"W 31 m a. s. l. STRI 1199, 1, 38.8 mm SL, Veraguas, San Pablo River, 8°11'59"N 81°15'2"W approximately 56 m a. s. l. STRI 1200, 1, 36.0 mm SL, Herrera, La Villa River, 7°54'5"N 80°31'24"W approximately 23 m a. s. l. STRI 1205, 2 c&s, 41.1–41.2 mm SL, Veraguas, Santa Maria River basin, Las Lajas River, 8°21'10"N 80°47'57"W approximately 225 m a. s. l. STRI 1208, 2, Chiriquí, Chiriquí River, creek on new highway at Gualaca, 8°36'30.6"N 82°17'51.1"W approximately 266 m a. s. l. STRI 1209, 2 c&s, 40.8–42.6 mm SL, Panama, Chame River, 8°39'10.0"N 79°57'71.3”W approximately 207 m a. s. l. STRI 5944, 2, 43.0– 43.3 mm SL, Coclé, Coclé del Norte River system, Toabre River, Tortuguita creek, Los Algarrobos creek, 8°52'43.0"N 80°23'25.7"W approximately 60 m a. s. l. STRI 5945, 2, 44.0– 44.1 mm SL, Coclé, Coclé del Norte River basin, Moreno River, 8°46’00”N 80°32’10.1”W approximately 106 m a. s. l. STRI 7654, 2, 34.0– 36.5 mm SL, Chiriquí, Chiriquí River, Grande creek, 8°27'52"N 82°22'36.7"W approximately 71 m a. s. l. UF 27525, 72, 20.0– 36.2 mm SL, Panama, at second bridge on Pan-American highway to N of route to El Valle, close to Chame River basin, approximately 8°33'49.37"N 79°53'35.13"W 30 m a. s. l. USNM 78556, 26 paratypes, 23.8– 36.5 mm SL (2 rad 34.4–36.5 mm SL), Panama, Chame River, approximately 8°34'24.59"N 79°53'14.83"W 15 m a. s. l. USNM 106513, holotype of Gephyrocharax whaleri , 39.5 mm SL (rad), male, Panama, streams crossed by highway between Campana and La Venta, R. P., approximately between 8°43'29.20"N 79°53'8.29"W 139 m a. s. l. and 8°27'43.85"N 79°58'33.37"W 43 m a. s. l. USNM 109276, 39 paratypes, 19.0– 47.9 mm SL, Panama, Canal Zone, streams crossed by highway between Campana and La Venta, approximately between 8°43'2920"N 79°53'829"W 139 m a. s. l. and 8°27'43.85"N 79°58'33.37"W 43 m a. s. l. USNM 235926 (previously USNM 109276), 2 paratypes, 37.2–40.1 mm SL (2 rad), Panama, Canal Zone, streams crossed by highway between Campana and La Venta, approximately between 8°43'29.20"N 79°53'8.29"W 139 m a. s. l. and 8°27'43.85"N 79°58'33.37"W 43 m a. s. l. USNM 236104, 5 c&s, 32.2–36.9 mm SL, Los Santos, La Villa River basin, Tebario River, about 3 miles to W of Llano de Piedra, approximately 7°40'7.11"N 80°34'41.67"W 115 m a. s. l.

Figures

FIGURE 1. Geographic distribution of Trans-Andean species of Gephyrocharax occurring west from eastern versant of Andean Cordillera in northwestern South America to southern Central America.

FIGURE 6. Tukey box plots of (A) number of maxillary teeth, (B) number of branched anal-fin rays, (C) number of branched pelvic-rays, and (D) number of lateral-line scales comparing among Gephyrocharax species. Number of specimens between brackets.

FIGURE 14. Gephyrocharax intermedius, (A) male, holotype, 44.2 mm SL, FMNH 8945; (B) female, paratype, 39.1 mm SL, FMNH 12512; (C) male, STRI 7654, 36.5 mm SL; (D) male, holotype of G. whaleri, 39.5 mm SL, USNM 106513; (E) female, paratype, 37.2 mm SL, USNM 235926.

FIGURE 15. Gephyrocharax intermedius, (A – B) upper and lower jaws, female, 40.8 mm SL, STRI 1209, right side; (C – D) detail of lower caudal skeleton and associated pouch scale, male, 42.6 mm SL, STRI 1209, left side. Anguloarticular: aa, dentary: dt, maxilla: mx, premaxilla: pm, pouch scale: ps, principal caudal-fin ray: pcr, retroarticular: ra, spur-shaped structure: sss, ventral procurrent ray: vpr. Lateral view. Scale = 1 mm.

FIGURE 16. Sheared principal component analysis of morphometric data of Gephyrocharax intermedius: (A – B) comparison among type specimens of G. intermedius and G. whaleri (its junior synonym); (C – D) comparison among specimens organized by geographic groups. Left plots (A and C) showing first and second principal components (PC 1 vs. PC 2), right plots (B and D) showing second and third principal components (PC 2 vs. PC 3). Sheared principal component: H, principal component centered by groups: S. Percentage of explained variance beside each component.

Tables

TABLE 4. Morphometric data of holotype (A), paratypes, and other examined species of Gephyrocharax intermedius. Ranges below including holotype (B) and paratypes of G. whaleri (junior synonym). Range of males containing these two holotypes values. M = mean; SD = standard deviation.

FMNH 8945	USNM 106513	n	Range	M	SD	n	Range	M	SD
Standard length (mm) 44.2	39.5	118	24.4–61.1	34.4	5.0	159	18.3–56.4	31.7	6.0
Percentages of standard length:
Depth at dorsal-fin origin 32.4	34.2	99	29.1–38.0	34.2	1.8	115	28.4–38.0	33.8	2.2
Snout to dorsal-fin origin 65.6 Snout to pectoral-fin origin 26.0	66.6 28.5	99 99	61.1–70.6 25.4–31.3	66.1 28.5	1.6 1.0	114 114	62.5–71.3 26.4–31.2	66.9 28.7	1.6 0.9
Snout to pelvic-fin origin 45.7	47.0	99	43.4–51.0	46.4	1.1	114	45.5–50.9	48.0	1.1
Snout to anal-fin origin 60.4	58.4	99	56.7–64.8	59.9	1.5	114	56.3–64.5	61.1	1.6
Dorsal fin to pectoral fin length 51.6	53.8	99	45.5–54.0	49.8	1.8	114	45.5–54.7	50.1	2.3
Dorsal fin to adipose fin length 26.5	22.9	97	22.7–28.9	26.0	1.2	114	22.9–28.7	25.9	1.1