Galeocharax goeldii ( Fowler, 1913 )

Menezes, Naércio A., 2007, Charax goeldii Fowler, 1913 a valid species of Galeocharax Fowler (Characiformes: Characidae), Neotropical Ichthyology 5 (1), pp. 21-24 : 21-23

Galeocharax goeldii ( Fowler, 1913)

Figs. 1 and 2

Charax goeldii Fowler, 1913: 568 (type locality: Madeira River, about 200 miles east of longitude 60º20’, Brazil; type examined; Schultz, 1950: 62 [as synonymous of Cyrtocharax amazonus (Günther) ]; Géry, 1972: 27-28 (redescription of type); Menezes, 1976: 43 [as synonymous of Galeocharax gulo (Cope) , based on Géry’s (1972: 72) data]; Böhlke, 1984: 47 (type catalog; possibly valid as Cynopotamus goeldii ); Eschmeyer, 1998: 657 (catalog; as synonymous of Galeocharax gulo ).

Cyrtocharax goeldii ; Fowler, 1950: 311 (synonymy; distribution).

Cynopotamus (Acestrocephalus) goeldii ; Géry & Vu-Tân-Tuê, 1963: 240 (diagnosis in key); Géry, 1972: 28-29 (taxonomic data; diagnosis in key).

Material examined. ANSP 39308, holotype, 44.3 mm SL, Brazil, Rondônia: tributary of rio Madeira near Porto Velho, Edgard A. Smith, January 1913. The following lots collected in Rondônia, rio Madeira between Guajará-Mirim and Porto Velho. MZUSP 92435, 3 of 4, 37- 99 mm SL, igarapé Belmont, 8º38’27"S 63º50’58"W; MZUSP 92436, 11 of 24, 25.7-84.9 mm SL, igarapé Karipuna, 9º15’10"S 64º38’31"W; MZUSP 92432, 2 of 5, 31- 39 mm SL, igarapé Simão Grande, 9º32’36"S 65º13’04"W; MZUSP 92433, 3 of 8, 44.5-49 mm SL, salto Jirau, 9º19’43"S 64º54’31"W; MZUSP 92434, 1, 109 mm SL, igarapé Diagnosis. Among the species presently assigned to Galeocharax , G. goeldii is most similar to G. gulo and G. knerii with respect to most meristic characters, with exception of the number of perforated lateral line scales (87-95 in G. goeldii vs 80-86 in G. gulo and G. knerii ). It differs from G. humeralis by having fewer perforated lateral line scales (87-95 vs 98-101 in G. humeralis ), fewer horizontal scale rows from dorsal-fin origin to lateral line(17-18 vs 20-22 in G. humeralis ) and fewer maxillary teeth (35-45 vs 47-52 in G. humeralis ).

Description. Morphometrics of holotype and all specimens examined presented in Table 1. Body elongate, moderately large (SL = 31-123 mm SL), compressed and moderately deep; greatest body depth slightly in advance of dorsal-fin origin. Dorsal body profile straight from tip of snout to anterior part of fontanel, slightly concave from that point to base of supraoccipital spine, convex from that point to dorsal-fin origin, nearly straight along dorsal-fin base and from end of dorsalfin base to caudal peduncle. Ventral body profile convex all the way 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 is totally closed. Maxilla extending slightly beyond vertical crossing posterior bor- der of orbit.

Dorsal-fin rays ii, 9 in all specimens, posterior most ray unbranched. Adipose fin present. Anal-fin rays iv or v, usually iv unbranched, branched rays 40-44 (iv,41), 41.9. Weakly developed anterior anal-fin lobe including anterior unbranched rays and first 7-8 branched rays. One male specimen (MZUSP 92434,109 mm SL) with bilateral hooks on posterior anterior 18 branched rays, number of hooks varying considerably: first branched ray with 18, fourth with 22, eighth with 14, tenth with 8, fifteenth with 8 and eighteenth with 1. Pectoral-fin rays i,14-17 (i,15), 15.5. Posterior tips of longest pectoral-fin rays reaching slightly beyond pelvic-fin origin. Pelvic-fin rays i,7. No hooks on pelvic-fin rays of sexually mature males. Distal tips of longest pelvic-fin rays reaching slightly beyond anal-fin origin in specimens of 40-90 mm SL, but only to or slightly beyond posterior border of anus in specimens larger than 100 mm SL. Principal caudal-fin ray count 10/ 9 in all specimens.

Lateral line complete, perforated scales 87-95 (87), 89.8. Horizontal scale rows above lateral line 17-19 (18), 17. Horizontal scale rows below lateral line 16-18 (18), 17.1. Scale rows around caudal peduncle 26-27 (26), 26.3. Three scale rows anteriorly along both sides of anal-fin base, reduced to one row posteriorly.

Premaxilla with two slightly enlarged inner conical teeth, an outer row with one anterior canine-like tooth followed by a row of 7-10 (10), 8.5 small conical teeth and another caninelike tooth. Anterior canine-like tooth outside anterior border of lower jaw when mouth closed. Maxillary teeth conical, highly variable in number, 35-46 (40), 39.5. Dentary with outer row of conical teeth which 4 anteriormost spaced and first, third and fourth larger than second, these followed by posterior row of 15-31 (18), 20.1, close-set conical teeth that show tendency to increase in number according to increase in standard length ( Fig. 3 ). An inner row of 7-11 (7), 9 conical dentary teeth.

Vertebrae 41-43 (42), 41.8. Number of gill-rakers on upper limb of first gill-arch 2 in all specimens. Number of gill-rakers on lower limb of first gill-arch 6-7 (6), 6.2.

Color in alcohol. Body pale to light yellow, slightly darker dorsally than ventrally due to presence of dark chromatophores mostly concentrated along free border of scales. Dorsal part of head from tip of snout to supraoccipital region darker than remaining part of head. Faint dark stripe from tip of supraoccipital spine backward not quite reaching dorsalfin origin. Faint dark small blotch at dorsal-fin origin. Lateral dark body stripe extending from upper opercle to caudal-fin base where it connects to irregular dark blotch posteriorly extending to anterior part of middle caudal-fin rays. Lateral body stripe narrower from dorsal-fin origin anteriorly to upper opercle and on caudal peduncle, broader from below dorsal-fin origin to below adipose fin, sometimes obscured by guanine. Irregularly shaped dark blotch in humeral region over anterior lateral body stripe, vertically above pectoral fin. Anterior part of lower jaw bordered with dark pigmentation along bases of four anterior large conical teeth. Premaxilla and anterior maxilla pigmented with dark. Patch of dark chromatophores on lower half of opercle. All fins hyaline.

Figures

Fig. 1. Galeocharax goeldii,ANSP 39308, holotype, 44.3 mm SL, tributary of Madeira River near Porto Velho, Brazil.

Fig. 2. Galeocharax goeldii, UNIR 0008, 123 mm SL, igarapé doArara, rio Madeira, Porto Velho, Rondônia.

Fig. 3. Scatter plot of number of posterior dentary teeth on standard length for all examined specimens ofGaleocharax goeldii.