Archocentrus spinosissimus ( Vaillant & Pellegrin, 1902 )

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 : 30-31

Archocentrus spinosissimus ( Vaillant & Pellegrin, 1902)

Figures 1, 4

Heros (Cichlasoma) spinosissimus Vaillant & Pellegrin 1902: 87 (original description).

Cichlasoma (Archocentrus) spinosissimum , Pellegrin 1904: 188 ( new combination).

Archocentrus spinosissimus , Allgayer1994: 15 ( new combination).

Lectotype. MNHN A-0352 , 69 mm SL (Fig. 4), F. Bocourt. Rio Polochic , Guatemala. The lectotype, herein designated, is the only one with an intact caudal fin.

Paralectotypes. MNHN 2005-0780 (3; 58, 59, and 74 mm SL).

Diagnosis. Autapomorphies (Schmitter-Soto, in press): vertical bar on head, extending just across nape, not present on opercle; distally three rows of anal interradial scales. In addition, caudal fin rounded-truncate (vs. definitely truncate) in the other species of Archocentrus .

Description. D. XVII-XIX,7-10; A. XI-XIII,7-9; gill rakers on lower limb of first arch 6-8; gill rakers bifid or at least distally expanded, trapezoidal, serrated. Scale rows on cheek 4-6; pored lateral-line scales (not counting scales overlapping between the two segments of the lateral line) 26-28; scales from lateral line to base of first dorsal-fin ray 3.5-4.5; circumpeduncular scales 19-21 (additional meristic data appear in Table 3).

Largest specimen observed, 74 mm SL, the species often reaching 110 mm SL according to Conkel (1993). Body rather oval, deeper than other species of Archocentrus (57-61% of SL), dorsal and ventral profiles almost symmetrical, or upper profile more strongly curved. Head profile straight above orbits, convex at nape. Head length 34-35% of SL, head deeper than long; orbital diameter 28-29% of head length (further morphometric data appear in Table 4). Maxilla not reaching a vertical line from anteriormost rim of orbit, but extending to a horizontal line from inferiormost rim of orbit; premaxilla reaching anterior rim of orbit. Teeth embedded, canine, pointed, cylindrical, rather long, slightly retrorse; symphysial teeth subequal to adjacent teeth. Lower jaw slightly protruding. Lower lip tapering, the ventral corner acute. Frenum present on lower lip.

Pectoral fins reaching posteriorly to 4th -8th anal-fin spine; pelvic fins reaching to 5th -10th anal-fin spine. Filamentous rays of dorsal fin extending posteriorly to distal fourth of caudal fin. Caudal fin rounded-truncate. Scales strongly ctenoid. Pored scales on caudal fin vestigial or absent; scales between dorsal and anal fin rays distally in two or three rows, up to 8 scales long.

Gut simple, anal and esophageal loops not adjacent. Genital papilla rounded or vase-shaped, wider than long; large feminine pore, tip crenulated to deeply notched; pigmented on margins (males) or just around opening (females).

A bar extending across nape from preopercle to preopercle; two interorbital bands; suborbital streak usually pointed, slightly concave dorsally; no stripe from snout to eye; speckles on cheek aligned from chin to angle of preopercle and along anteroventral edge of opercle; only one opercular spot, which is part of a longitudinal stripe running from orbit to lateral blotch. Eyes coppery, bluish. Seven vertical bars on sides, rather diffuse; 1st bar diffusely Y-shaped; 1st to 5th sometimes double, none extending onto dorsal fin; a squarish or rounded spot on 3rd bar. No ocellus on dorsal; dots on soft dorsal and anal fins in 4-6 rows, concentric on base of third or fourth ray, a basal row all along dorsal fin. About 10-14 rows of well-marked spots on sides, smaller than scales; breast region olive. Base of pectoral fin paler than breast, sometimes yellowish. Caudal blotch on scaly base of fin, extending across lateral line, never forming a saddle over top of caudal peduncle, connected to posterior speckles between rays of caudal fin.

Distribution. Ríos Polochic, Dulce, and other rivers in Lago Izabal drainage, Caribbean versant of Guatemala (Fig. 1).

Remarks. Pellegrin (1904) considered that the species “ présente tout à fait l’aspect d’ Herotilapia multispinosa […] elle n’est pas éloignée de C. nigrofasciatum […] et de C. centrarchus …”

Cichlasoma spinosissimum var. immaculata Pellegrin (1904) , which occurs sympatrically with A. spinosissimus (and with Cryptoheros spilurus ) in the Río Polochic, was considered a valid species by Regan (1905) and Miller (1966), mainly because it lacks speckles on the fins and has up to 19 dorsal fin spines, as few as 9 anal-fin spines, and as many as 29 pored lateral-line scales. Pellegrin himself (1904) was of the opinion that, in spite of the differences, it was not possible to categorically separate this form to species (he even called it a “variety,” not a subspecies). Allgayer (2001) noted that it might be the female of Archocentrus spinosissimus , the reduction or absence of speckles being a “fait aussi observé en captivité.” After examining the types, I conclude that they are somewhat decolored (although not totally descaled, contra Allgayer 2001) specimens of Cryptoheros spilurus . Thus, Cichlasoma immaculatum (the nomen used for this taxon by Regan [1908] and Miller [1966]) is hereby synonymized with Cryptoheros spilurus , as discussed in the account of that species.