Charax metae Eigenmann, 1922

Menezes, Naércio A. & de Lucena, Carlos Alberto S., 2014, A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil, Neotropical Ichthyology 12 (2), pp. 193-228 : 211-212

Charax metae Eigenmann, 1922

Fig. 16

Charax metae Eigenmann, 1922: 238 (original description, type locality: Colombia, Barrigón, Orinoco system, río Meta). - Ibarra & Stewart, 1987: 22 (listed in type catalog). -Lucena, 1987: 44 (diagnosis; description; distribution). -Lucena, 1989: 201 (in key to species). - Vari & Howe, 1991: 13 (listed in type catalog). - Lucena & Menezes, 2003: 201 (maximum length; distribution).

Diagnosis. Charax metae , Charax delimai , C. tectifer , some specimens of C. gibbosus , C. rupununi , and C. condei are the only species of the genus bearing teeth on the ectopterygoid bone. Charax metae differs from C. condei by having the lateral line complete (versus incomplete), from C. gibbosus and C. rupununi which have the anal-fin origin anterior to the vertical through the dorsal-fin origin in having the anal-fin origin through vertical or slightly posterior to, dorsal fin-origin. Charax metae can be readily distinguished from C. tectifer by the presence (vs. absence) of the dorsoventrally arranged superficial neuromasts on the trunk scales ( Fig. 2 ), except the lateral line and from C. delimai by having more ectopterygoid teeth (20-50 vs. 3-15), fewer transverse scale rows between the humeral spot and the supracleithrum (7-9 vs. 10-12) and the humeral spot distance 41.6-47% of SL (vs. 48-51% of SL, Fig. 3 ).

Description. Morphometrics of examined specimens presented in Table 9. Body elongate, moderately large (37-99 mm SL), compressed and moderately deep. Greatest body depth slightly in advance of dorsal-fin origin. Dorsal profile of head and body convex from tip of snout to anterior portion of fontanel, concave from that point to base of supraoccipital spine, convex from that point to dorsal-fin origin, nearly straight along dorsal-fin base, straight to slightly convex from end of dorsal-fin base to caudal peduncle and slightly concave along caudal peduncle. Ventral profile of head and body convex from tip of lower jaw to anal-fin origin, nearly straight along anal-fin base and slightly concave from end of anal-fin base to beginning of procurrent rays. Snout pointed. Lower jaw included in upper jaw when mouth closed. Maxilla extending slightly posterior to vertical through posterior border of orbit.

Dorsal-fin rays ii, 9 in all specimens; posterior most ray unbranched. Adipose fin present. Unbranched anal-fin rays iv or v, usually iv, branched rays 39-43, 41.2. Pectoral-fin rays i, 14-16, 14.7. Tips of longest pectoral-fin rays reaching to about vertical through middle of pelvic fin length. Pelvic-fin rays i, 7. Tips of longest pelvic-fin rays reaching slightly beyond anal-fin origin. Principal caudal-fin ray count 10/ 9 in all specimens.

Lateral line complete; perforated scales 51-55, 53.5. Horizontal scale rows from dorsal-fin origin to lateral line 12- 13, 12.4. Horizontal scale rows from pelvic-fin origin to lateral line 9-10, 9.9. Horizontal scale rows from anal-fin origin to lateral line 11-13, 12.3. Predorsal scales 30-36, 33.3. Scale rows around caudal peduncle 19-21, 20. Scale row extending for about two thirds of anal-fin base. Basal portions of trunk scales except for those on lateral line bearing dorso-ventrally arranged superficial neuromasts in specimen with unidentified sex ( Fig. 2 ).

Premaxillary with one anterior canine-like tooth followed by set of smaller conical teeth and another canine-like tooth followed by one or two small conical teeth. Total number of premaxillary teeth 11-14, 12.5. Maxillary teeth conical, 44-56, 48.7; larger specimens generally with higher counts. Dentary with one canine-like tooth followed by 6-8, 6.5 conical teeth, another canine-like tooth and a posterior row of 17-25, 21.2 conical teeth. Left ectopterygoid bone with 10-27, and right with 10-23 conical teeth. Total number of ectopterygoid teeth 20-50, 29.7.Vertebrae 33 and 34 (2). Gill-rakers on lower limb of first gill-arch 7-9, 8.3. Branchiostegal rays 4; 3 rays originating from anterior ceratohyal and 1 from posterior ceratohyal.

Color in alcohol. Old preserved specimens show overall pale to light brown body coloration with scattered dark chromatophores especially concentrated on basal portion of scales on anterior midbody region. Superficial neuromasts vertically arranged along skin of basal portion of each scale in most specimens whitish and contrasting with background dark coloration of the scale basal portion ( Fig. 2 ). Irregularly shaped humeral dark blotch region, much closer to dorsal-fin origin than to posterior border of opercle, encompassing about four scales vertically and horizontally. Dark blotch on caudal peduncle approximately triangular shaped, higher posteriorly and extending over basal portions of median caudal-fin rays. Scattered dark chromatophores on the tips of the snout and the lower jaw. Tip of dorsal fin dark. Anal fin with faint basal dark stripe, separated by light stripe from more conspicuous dark wider distal stripe extending to end of fin. Tip of pelvic fins dark. Pectorals light with few scattered dark chromatophores. Marginal portion of caudal fin dark with scattered dark chromatophores.

Distribution. Charax metae is known from the río Meta, Colombia ( Fig. 7 ).

Specimens examined. CAS 69117, 16 paratypes, 37-87 mm SL, Colômbia, Meta, Puerto Barrigona (=Barrigón) at head of navigation east of Bogota, approximately 10°34’N 75°11’W, 73°45’W .

Figures

Fig. 16. Charax metae, CAS 69117, 87 mm SL, Colômbia, Meta, Puerto Barrigona (=Barrigón) at head of navigation east of Bogota.

Fig. 2. Superficial neuromasts (black arrow) on ventral body scales of Charax metae, CAS 69117, 59 mm SL.

Fig. 3. Humeral spot distance as a function of standard length for species of Charax.

Fig.7. Map of SouthAmerica showing the collecting sites of the Charax species, and the type locality of Charax delimai (purple circle). Charax apurensis - yellow square; C. caudimaculatus - white circle; C. condei - white square; C. gibbosus - purple triangle; C. hemigrammus - red star; C. leticiae - black circle;C. macrolepis-black triangle;C.metae-yellow triangle;C.michaeli - yellow circle;C.niger -blue triangle; C.notulatus - blue circle; C. pauciradiatus - red triangle; C. rupununi - red circle; C. stenopterus - green triangle; C. tectifer - green circle. Some symbols may represent more than one locality.