Charax michaeli Lucena, 1989

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 : 212-214

Charax michaeli Lucena, 1989

Figs. 17-18

Charax michaeli Lucena, 1989: 98 (original description, type locality: Brazil, Roraima, in front of ilha Maracá, rio Branco basin, igarapé Cujobim. -Oyakawa, 1996: 455 (listed in catalog). - Lucena & Menezes, 2003: 201 (maximum length; distribution).

Charax unimaculatus Lucena, 1989: 101 (type locality: Brazil, Amazonas , lago Manacapuru (3°00’36.8"S 61°20’18.6"W); holotype and paratypes examined. - Oyakawa, 1996: 456 (listed in catalog). - Lucena & Menezes, 2003: 202 (maximum length; distribution).

Diagnosis. Charax michaeli differs from C. caudimaculatus and C. notulatus ) in the orbital diameter 30.1-38.4% of HL ( Fig. 4 ) (vs. 25-28.5% of HL). Charax michaeli can be distinguished from C. apurensis and C. macrolepis by the number of scale rows around the caudal peduncle (17-19 vs. 20-22) and from C. pauciradiatus , C. gibbosus , C. niger , and C. leticiae in having 18-20 (vs. 13-17) scale rows from the dorsal-fin origin to the lateral line. Charax michaeli differs from C. hemigrammus , C. condei , and C. stenopterus by having a complete lateral line (vs. lateral line incomplete), from C. rupununi by the number of scales around caudal peduncle (17-19 vs. 12) and 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 along vertical or slightly posterior to, vertical through the dorsal-fin origin) and ectopterygoid teeth absent (vs. ectopterygoid teeth present).

Description. Morphometrics of examined specimens presented in Table 10. Body elongate, moderately large (37- 155 mm SL), compressed and deep. Greatest body depth slightly in advance of dorsal-fin origin. Dorsal profile of head and body slightly convex on tip of snout, straight from posterior border of posterior nostril to vertical line through posterior border of pupil, slightly concave from that point to base of supraoccipital spine, very strongly convex from that point to dorsal-fin origin, nearly straight along dorsal-fin base and from end of dorsal-fin base to caudal peduncle and slightly concave above 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 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 beyond vertical through posterior border of pupil.

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 45-54, 49.5. Sexually mature male (MZUSP 33417, 80 mm SL) with tiny hooks on anterior anal-fin rays ( Fig. 18). Pectoral-fin rays i, 11-16, 13.4. Tips of longest pectoral-fin rays reaching about to middle of pelvicfin length. Pelvic-fin rays i, 7. Sexually mature males with tiny hooks on branched pelvic-fin rays ( Fig. 18); male specimen (MZUSP 33417) with about 12 hooks on first branched ray, 26 on second, 25 on third, 25 on fourth, and 15 on fifth. Distal tips of longest pelvic-fin rays reaching vertical through bases of second to fifth branched anal-fin rays. Principal caudal-fin ray count 10/ 9 in all specimens.

Lateral line complete; perforated scales 53-60, 57.6. Horizontal scale rows from dorsal-fin origin to lateral line 18- 20, 18.1. Horizontal scale rows from pelvic-fin origin to lateral line 9-11, 10.1. Horizontal scale rows from anal-fin origin to lateral line 11-14, 12.8. Predorsal scales 57-85, 66.8. Scale rows around caudal peduncle 17-19, 18. Scale row along anal-fin base extending for about ¾ 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 10-17, 13.3. Maxillary teeth conical, 52-86, 65.7; larger specimens generally with higher counts. Dentary with one canine-like tooth followed by 3-8, 4.5 conical teeth, another canine-like tooth and posterior row of 21-38, 30 conical teeth. Gill-rakers on lower limb of first gill-arch 8-9, 8.7. 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 than on lateral and ventral regions. Ventral portions of body lighter with scattered dark chromatophores especially posteriorly. Dorsal portions of head, snout and tip of lower jaw darker than remainder of head. Dark chromatophores spreading over first, second, most of third, fourth, fifth and sixth infraorbitals, between second and third infraorbitals, median portion of lower jaw and median portion of maxilla. Scattered dark chromatophores on lower central portion of preopercle, and most of opercle. Oval-shaped vertically elongate dark humeral blotch slightly roundish in some specimens encompassing about 2 to 4 scales horizontally and 3 to 5 scales vertically. Triangular, dark blotch on caudal base, faint or even absent in some specimens; dark chromatophores extending over bases of median caudal-fin rays. Inconspicuous dark lines of chromatophores along miosepta of epaxial muscles above lateral line and miosepta of hypaxial muscles below lateral line, forming V-shaped patterns more conspicuous posteriorly. Faint dark lateral stripe extending from behind dorsalmost part of opercle to caudal blotch. All fins hyaline with scattered dark chromatophores more visible on interradial membranes. Inconspicuous clear stripe extends slightly below anal-fin base across entirety of fin.

Anterior portion of first and second unbranched dorsalfin rays and first unbranched rays of pectoral and pelvic fins darker than remaining rays.

Distribution. Charax michaeli is widely distributed in drainages throughout theAmazon basin and has been collected in tributaries of the rio Branco basin; tributaries of the rio Solimões near Manaus; tributaries of the rio Negro, Amazonas; and tributaries of the rio Jari, Amapá, Brazil ( Fig. 7 ).

Sexual dimorphism. Females lack the tiny anal-fin hooks described above for males and usually reach on average larger body sizes than males. Males with fully developed testes and anal- and pelvic-fin hooks (MZUSP 33417) ranged between 49 and 80 mm SL, whereas females with fully mature ovaries (MZUSP 79607, MZUSP 33436, MZUSP 102313, MZUSP 35952, MZUSP 93071, MZUSP 93450, MZUSP 103424 and MZUSP 33417) ranged between 76 and 135 mm SL.

Remarks. Comparison of meristic and morphometric data of the holotype and all the paratypes of Charax unimaculatus Lucena, 1989 with the same data of the examined specimens of C. michaeli indicated no differences. The differences between the two species reported by Lucena (1989) are not significant since the shape of the humeral dark blotch (pointed out as roundish in C. unimaculatus and vertically elongate in C. michaeli and the absence of a dark caudal-fin blotch in the former species) vary considerably. In the specimens of Charax michaeli examined the shape of humeral blotch varies from roundish to vertically elongate and the spot on the caudal-fin base is absent or faint.

Specimens examined. Brazil: Amazonas: MZUSP 6534 , 65 mm SL, (holotype of Charax unimaculatus ), lago Manacapuru, 3°00’36.8"S 61°20’18.6"W ; MZUSP 37277 , 1 , 86 mm SL, (paratype of Charax unimaculatus , collected with holotype) ; MCP 11253, 3 , 76-88 mm SL, (paratypes of Charax unimaculatus ), Manaus, lago Januari, approximately 2°37’S 60°56’W ; MZUSP 6878 , 8 , 73-86 mm SL, (paratypes of Charax unimaculatus ), Manaus, lago Januari, approximately 2°37’S 60°56’W ; MZUSP 6673 , 12 , 54-75 mm SL, (paratypes of Charax unimaculatus ), rio Negro , around Manaus ; MZUSP 6459 , 4 , 73-83 mm SL, (paratypes of Charax unimaculatus ), above Manacapuru, lago Jacaré, right bank of rio Solimões , approximately 3°15’S 60°33’W ; MZUSP 19779 , 5 , 60-76 mm SL, (paratypes of Charax unimaculatus ), lake near canal of lago Janauacá, approximately 3°19’S 60°16’W . Additional specimens. Amazonas : MZUSP 31438 , 1, 114 mm SL, Santa Isabel do Rio Negro, ilha Marubim, rio Marauiá , 0°24’S 65°12’W ; MZUSP 92375 , 2 , 93-98 mm SL, community of Serra da Mucura, rio Tiquié, rio Negro drainage, 0°10’N 69°07’W ; MZUSP 92550 , 3 , 53-97 mm SL, igarapé Castanha, tributary of rio Tiquié, rio Negro drainage, 0°12’N 69°07’W ; MZUSP 75071 , 79 mm SL, Urucará, paraná de Urucará, 2°32’11"S 57°45’37"W ; MZUSP 75603 , 2 , 56-57 mm SL, paraná do Janauacá, approximately 3°25’S 60°54’W ; MZUSP 75604 , 4 , 38-56.5 mm SL, Camaleão, ilha da Marchantaria , 2°45’33"S 57°48’24"W ; MZUSP 75607 , 1 , 79 mm SL, paraná do Janauacá entering lago Castanho, approximately 3°25’S 60°54’W ; MZUSP 75608 , 1 , 44 mm SL, Amazonas, Janauari, lago Terra Preta ; MZUSP 38769 , 2 , 66-78.5 mm SL, igarapé on right bank of canal do Janauacá, 3°22’S 60°11’W ; MZUSP 63282 , MZUSP 63283 , 10 , 50-84 mm SL, Tefé, rio Tefé , 3°22’S 64°43’W ; MZUSP 33436 , 6 , 108- 123 mm SL, lake on bank of rio Marauiá, rio Negro drainage, 0°24’S 12°00’W ; MZUSP 93071 , 1, 126 mm SL, near sítio São Pedro, igarapé Castanha, tributary of rio Tiquié, rio Negro drainage, 0°08’N 69°35’W ; MZUSP 93342 , 1, 116 mm SL, community of Pirarara-Poço, rio Tiquié, rio Negro drainage, 0°08’N 69°12’W ; MZUSP 63206 , 6 , 46-67 mm SL, Tefé, lago Amanã, mouth of rio Japurá , 2°38’S 64°39’W ; MZUSP 93450 , 1, 135 mm SL, near community of Serra da Mucura, rio Tiquié, rio Negro drainage, 0°10’00"N 69°07’00"W ; MZUSP 6673 , 6 , 60-75 mm SL, Manaus, rio Negro , 03°10’S 60°00’W ; Amapá: MZUSP 102313 , 22 , 46- 11 mm SL, Laranjal do Jari, right bank of rio Jari, near Cachoeira de Santo Antônio , 0°56’S 52°33’W ; MZUSP 101715 , 5 , 76-80 mm SL, Laranjal do Jari, Cachoeira de São Raimundo, rio Iratapuru , 0°33’59"S 52°34’40"W ; MZUSP 101788 , 6 , 72-92 mm SL, Laranjal do Jari , upper portion of Cachoeira Santo Antônio, 0°34’16"S 54°39’31"W ; Acre: MZUSP 49769 , 2 , 72-80 mm SL, between seringal do Paraíso and lago Amapá, not precisely located; Pará : MZUSP 101544 , 2 , 72-84 mm SL, Monte Dourado, rio Jari , 0°35’38"S 52°38’55"W ; MZUSP 103424 , 2 , 69-89 mm SL, Monte Dourado, upper portion of Cachoeira de Santo Antônio, rio Jari , 0°36’S 52°31’W .

Figures

Fig. 17. Charax michaeli, MZUSP 92343, male, 116 mm SL.

Fig. 4. Orbital diameter as a function of head 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.