Archocentrus centrarchus ( Gill, 1877 )

Juan J. Schmitter-Soto, 2007, A systematic revision of the genus Archocentrus (Perciformes: Cichlidae), with the description of two new genera and six new species., Zootaxa 1603, pp. 1-78 : 12-28

Archocentrus centrarchus ( Gill, 1877)

Figures 1-2

Heros (Archocentrus) centrarchus Gill in Gill & Bransford 1877: 185 (original description).

Cichlasoma (Archocentrus) centrarchus , Jordan & Evermann 1898: 1526 ( new combination).

Archocentrus centrarchus , Allgayer 1994: 15 ( new combination).

Holotype. USNM 16878 , J. F. Bransford, Mar. 1, 1876. Lake Nicaragua , Nicaragua. No paratypes (see Remarks).

Diagnosis. Autapomorphies (Schmitter-Soto, in press): total gill rakers on first arch 16-19; gill rakers elongate, slender; two opercular spots, vertically aligned. Further diagnosed from other species of Archocentrus by absence of a concavity at posterior end of maxilla; circumpeduncular scales modally 18 or fewer (vs. 19 or more); presence (vs. absence) of rows of secondary pored scales on caudal fin; bars on side of body extending partially onto dorsal and anal fins (vs. bars confined to sides of body), absence (vs. presence) of medial intensification in bars on side of body, presence (vs. absence) of ocellus on dorsal fin of mature females; abdomen predominantly yellow-green in life (vs. abdomen predominantly bluish, whitish, yellow or black); and caudal blotch ocellated (vs. not ocellated).

Description. D. XV-XVII,7-9; A. IX-XI,7-9. Gill rakers on lower limb of first arch 12-17; gill rakers long, especially on ventral side, and serrated. Scale rows on cheek 4-6; pored lateral-line scales (not counting scales overlapping between the two segments of the lateral line) 25-29; scales from lateral line to base of first dorsal-fin ray 1.5-3; circumpeduncular scales 15-17. Additional meristic data appear in Table 3.

Largest examined specimen 102 mm SL. Body rather oval, deep (50-57% of SL), horizontally almost symmetrical in profile. Head profile straight or concave above orbits, convex at nape. Head length 33-34% of SL; orbital diameter 24-27% of head length (further morphometric data appear in Table 4). Maxilla extending to ventral rim of orbit; premaxilla extending to anterior rim of orbit. Teeth embedded, conical, slightly retrorse, upper symphysial teeth not abruptly larger, lower symphysial teeth subequal to adjacent teeth. Lower jaw slightly protruding. Lower lip at corner of mouth not tapering, rounded or squarish. Frenum of lower lip usually absent (not “present”, contra to the original description).

Pectoral fins reaching posteriorly to 5th-6th anal-fin spine; pelvic fins reaching to 6th-9th anal-fin spine; distal pelvic ray not bearing filaments. Filamentous rays of dorsal fin extending to about middle of caudal fin. Caudal fin definitely truncate to slightly emarginate. Scales weakly ctenoid. Subsidiary pored scales on caudal fin forming 3-scale-long rows; scales between anal fin rays in one or two rows, 6-11 scales long.

Gut simple, about as long as body; intestinal anal and esophageal loops adjacent. Genital papilla tongueshaped, in adults deeply notched or strongly crenulate; longer than wide in females, may be wider than long in males; pigmented on tip, but with little pigment on posterior side.

A vertical bar on head; two interorbital bands; a suborbital streak; diffuse stripe from snout to eye; no speckles on cheek; two spots characteristically on opercle. Eyes golden, yellow or reddish. Seven vertical bars on sides; 1st bar curved on head, all bars well marked medially and dorsally, 4th and 6th bars extending onto dorsal fin, no lateral spot discernible on bars. Blotch on dorsal fin over 6th bar sometimes ocellated; soft dorsal fin occasionally with two rows of dots forming a checkered pattern, but elsewhere unpaired fins mostly immaculate,. Rows of spots on sides 11-14, smaller than scales; breast region golden in juveniles, bronzegreen in adults. Axil of pectoral fin and base of pectoral fin with same coloration as breast. A black caudal blotch, on fin, across lateral line (not “chiefly above,” contra the original description), ocellated.

Distribution. Pacific slope, in tributaries of the Golfo de Fonseca, Honduras and Nicaragua; Atlantic slope, from the Río Chirripó ( Río Matina) of Costa Rica to the Río San Juan and associated drainages of Nicaragua, including the Great Lakes (Fig. 1).

Remarks. Although the specimen BMNH 1905.3.27.2 (Fig. 2) is labeled “cotype”, Gill and Bransford (1877: 186) left no doubt that they had only one specimen (i.e., the holotype) at hand. The BMNH specimen therefore has no formal type status.