Charax caudimaculatus Lucena, 1987

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 : 199-200

Charax caudimaculatus Lucena, 1987 Fig. 8

Charax caudimaculatus Lucena, 1987: 32 (original description, type locality: Peru, Laguna Chica, Reserva Nacional de Tambopata , Madre de Dios, 12°50’30"S 69°17’30"W. - Vari & Howe, 1991: 13 (listed in type catalog). - Lucena, 1989: 104 (in key to species). - Chang & Ortega, 1995: 2 ( Peru, listed). - Lucena & Menezes, 2003: 201 (maximum length; distribution). - Ortega et al., 2012: 35 ( Peru, listed).

Diagnosis. Charax caudimaculatus and C. notulatus differ from C. apurensis , C. macrolepis , C. michaeli , C. pauciradiatus , C. gibbosus , C. niger , and C. leticiae by having the orbital diameter 25.0-28.5% of head length (vs. 30.1-38.4% of head length, Fig. 4 ), and differ among themselves in the snout length (20.3-22.8% in C. caudimaculatus vs. 24.3- 26.3% in C. notulatus , Fig. 5 ), the number of scale rows from the dorsal-fin origin to the lateral line (16-17 vs. 18-19), and the number of scale rows from the anal-fin origin to the lateral line (9-13 vs. 14-17). Charax caudimaculatus can be distinguished from C. hemigrammus , C. condei , and C. stenopterus by having the lateral line complete (vs. lateral line incomplete), and from C. rupununi by the number of scales around the caudal peduncle (16-17 vs. 12). C. caudimaculatus differs from C. tectifer , C. metae , and C. delimai by having the anal-fin origin always anterior to the vertical through the dorsal-fin origin (vs. anal-fin origin on the vertical or slightly posterior to, the dorsal-fin origin) and ectopterygoid teeth absent (vs. ectopterygoid teeth present).

Description. Morphometrics of specimens examined presented in Table 2 . Body elongate, moderately large compared to congeners (31-123 mm SL), compressed and moderately deep. Greatest body depth slightly in advance of dorsal-fin origin. Dorsal of head and body profile slightly convex along tip of snout, straight from posterior border of posterior nostril to vertical crossing posterior border of pupil, slightly concave from that point to base of supraoccipital spine, strongly convex from that point to dorsal-fin origin, nearly straight along dorsal-fin base and from end of dorsalfin 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 posteriorly slightly beyond vertical through posterior border of pupil.

Dorsal-fin rays ii, 9 in all specimens; posteriormost ray unbranched. Adipose fin present. Unbranched anal-fin rays iv or v, usually iv, branched rays 46-54, 50.6. Pectoral-fin rays i, 13-15, 13.5. Tips of longest pectoral-fin rays extending to, or slightly beyond, anal-fin origin. Pelvic-fin rays i, 7. Tips of longest pelvic-fin rays reaching vertical between bases of sixth or seventh anal-fin rays. Principal caudal-fin ray count 10/ 9 in all specimens.

Lateral line complete, perforated scales 51-56, 53.2. Horizontal scale rows from dorsal-fin origin to lateral line 16- 17, 16.2. Horizontal scale rows from pelvic-fin origin to lateral line 9-11, 10. Horizontal scale rows from anal-fin origin to lateral line 9-13, 11.8. Predorsal scales 47-55, 50.6. Scale rows around caudal peduncle 16-17, 16.6. One scale row extending along anal-fin base to slightly beyond middle of fin base.

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 9-12, 13.6. Maxillary teeth conical, 58-78, 61, larger specimens in general with higher counts. Dentary with one canine-like tooth followed by 4-5, 4.4 conical teeth, another canine-like tooth and posterior row of 24-30, 27.1 conical teeth.

Vertebrae 33 and 34 in two specimens. Eight to 9, 8.5 gillrakers on lower limb of first gill-arch. Branchiostegal rays 4; 3 rays originating from anterior ceratohyal and 1 from posterior ceratohyal.

Color in alcohol. Body pale to light yellow, slightly darker dorsally due to denser concentration of dark chromatophores. Ventral region of body lighter with scattered dark

chromatophores especially anteriorly. Irregularly shaped vertically elongate, dark blotch on humeral region extending about 3 scales horizontally and 5 to 6 scales vertically. Blotch darker on lower half due to denser concentration of dark chromatophores. Dorsal part of head, snout and tip of lower jaw darker than remainder of head; dark coloration extending to anterodorsal portion of maxilla and first, second and anterior portion of third infraorbitals. Dorsal part of opercle and preopercle and fifth and sixth infraorbitals with scattered dark chromatophores. Diamond shaped dark blotch on caudal-fin base extending onto base of median caudal-fin rays. Patch of dark chromatophores over posterior portion of middle caudal fin. Pectoral and pelvic fins hyaline with scattered dark chromatophores. Caudal and anal fins hyaline with small dark chromatophores especially concentrated on posterior portions of interradial membranes. Same pattern on dorsal fin, but dark chromatophores inconspicuous, except on first dorsal-fin ray. Pelvic fins hyaline with scattered dark chromatophores.

Distribution. Examined specimens of Charax caudimaculatus originated from the Reserva Nacional de Tambopata, Madre de Dios, Peru ( Fig. 7 ).

Specimens reexamined. Peru: USNM 236877 , 9 paratypes, 52.5- 90.5 mm SL, Madre de Dios, Reserva Nacional de Tambopata, Laguna Cocococha , 12°49’S 69°30’W .

Figures

Fig. 8. Charax caudimaculatus, USNM 236877, female, paratype, 95 mm SL, Peru, Madre de Dios, Reserva Nacional de Tambopata, Laguna Cocococha.

Fig. 4. Orbital diameter as a function of head length for species of Charax.

Fig. 5. Snout length as a function of head length for Charax caudimaculatus and C. notulatus.

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.