Hypsophrys nematopus ( Guenther , 1867 ) Juan J. Schmitter-Soto, 2007

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 : 65-66

Hypsophrys nematopus ( Guenther, 1867) , n. comb.

Figures 27, 29

Neetroplus nematopus Guenther, 1867: 603 (original description).

Neetroplus fluviatilis Meek, 1912: 74 (junior synonym).

Neetroplus nicaraguensis Gill in Gill & Bransford, 1877:186 (non Günther, junior synonym).

Holotype. BMNH 1865.7.20.35 , 94 mm SL (Fig. 29), J. M. Dow. Lake Managua , Nicaragua. No paratypes.

Diagnosis. Many unique autapomorphies (fig. 6c in Schmitter-Soto, in press): Teeth properly incisor, even in young; caudal edge of mesethmoid with a sui generis shape; caudal edge of supraoccipital crest straight, inclined rostrad; supraoccipital crest height 27% of postethmoid skull length; width of posterior premaxillary expansion greater than 41% of length of same bone; arms of articular equal in length; gut S-folded ventrorostrally in adults, anal and medial loops nearly touching. Further distinguished from the other species in the genus by the abrupt, steep head profile.

Description. D. XVIII-XIX (modally XVIII),9-10; A. VII-VIII,6-7 (modally VII,7); pectoral 16-17. First dorsal fin ray not divided. Gill rakers on lower limb of first arch 8; gill rakers distally broadened, ventrad curved. Subsidiary pored scales on caudal fin in short rows. Scale rows on cheek 5-6; pored lateral-line scales (not counting scales overlapping between the two segments of the lateral line) 30-32; scales from lateral line to origin of dorsal fin 6.5-7, the dorsalmost pair reduced; scales from vent to interpelvic scale 13-17; anal creases modally 15 (further meristic data appear in Table 3).

Largest specimen examined, 94 mm SL, maximum size 140 mm SL ( Conkel 1993). Body depth 38-46% of SL (further morphometric data appear in Table 4). Teeth not embedded; symphysial teeth equal in level to adjacent teeth. Upper lip medially narrow; lower lip at corner of mouth tapering.

Pelvic fins inserted far behind origin of dorsal fin. Pectoral fins never reaching 1st anal-fin spine; pelvic fins always reaching at least 5th anal-fin spine in adults. Caudal fin slightly but definitely emarginate, contra Günther (1869), who described it as truncate (but depicted it as emarginate in his plate LXXIV, fig. 4). Scales moderately ctenoid in young, weakly so in adults.

Gut simple in juveniles, but the basic S-shape becoming ventrorostrally folded with growth, and anal loop displaced caudad until almost touching median loop (fig. 24i in Schmitter-Soto, in press). Gut length ca. 80% of SL. Genital papilla rounded, semicircular, broader than long, or squarish; sunk; pigmented on margins.

A diffuse stripe from snout to eye; an indistinct vertical bar on head. Eyes blue-silver. Seven bars on sides, diffuse, except 3rd, which constitutes a large, vertically elongated lateral blotch (this bar may be light on a dark background instead of dark on light in some color phases); no longitudinal stripe; no blotch on caudal fin, just base of fin darkened, same as last scales on peduncle. No dots on fins, but often hyaline areas near tip of soft dorsal and anal fins. No spots on scales; breast dark olive. Axil of pectoral fin dusky or darkened; base of pectoral fin whitish or with same coloration as breast.

Distribution. Río Santa Clara, Costa Rica, north to lakes Nicaragua and Jiloá, Nicaragua (Fig. 27).

Remarks. The “incisor” teeth of Cr. panamensis are not a true convergence, but a different character state ( Rogers 1981; Schmitter-Soto, in press).