Rocio gemmata Contreras-Balderas & 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 : 61-62

Rocio gemmata Contreras-Balderas & Schmitter-Soto , new species

Figures 22, 26

Archocentrus aff. octofasciatus , Schmitter-Soto 1998: 156 (preliminary detection).

Holotype. ECOCH 4054 , 64 mm SL (Fig. 26), the author, Jun. 11, 1999. Nameless cenote 12 km N of Leona Vicario , Quintana Roo, Mexico.

Paratypes. ECOCH 1468, 3145 , collected at the same karstic sinkhole by the author and H. C. Gamboa-Perez , and UANL 15046 (4), collected at Laguna Leona Vicario by S. Contreras-Balderas, co-discoverer of the species .

Diagnosis. Unique autapomorphies (fig 14e in Schmitter-Soto, in press): spots on sides, larger than scales and not clearly aligned (vs. smaller than scales and rather well-aligned); stripe from snout to eye interrupted (vs. continuous); quadrate bone with a spine (vs. without a spine). In addition, maxilla reaching both a vertical and a horizontal line from orbit (vs. just to the ventral rim); cheek-scale rows modally 7 (vs. 6 or fewer); interradial scales on dorsal fin in one row (vs. distally in two rows); dorsal and anal fins not bearing filaments (vs. bearing filaments); anal and medial gut-loops not adjacent, well separated by the stomach and the liver (vs. always adjacent); rostral end of maxilla notched or at least concave (vs. convex, with no notch); caudal ocellus blue in life (vs. white).

Description. D. XVIII,9-10; A. VIII -IX,7-8; pectoral 15-16. Gill rakers trapezoidal, bifid in larger specimens, their posterior ridge serrated. Scale rows on cheek 7; predorsal scales 14-15; pored lateral-line scales (not counting scales overlapping between the two segments of the lateral line) 28-30; scales from lateral line to origin of dorsal fin 4-4.5; scales from lateral line to base of first dorsal-fin ray 3.5 (further meristic data appear in Table 3).

The smallest species of the genus Rocio ; largest specimen examined, 70 mm SL. Body depth 41-46% of SL. Head length 35-41% of SL; orbital diameter 25-30% of head length (further morphometric data appear in Table 4). Head profile convex, straight above orbits. Lower lip at corner of mouth slightly curved downward, tapering.

Pectoral fins often falling short of first anal-fin spine, pelvic fins always reaching at least first anal-fin spine. Dorsal and anal fins not bearing filaments. Just one row, up to 4 scales long, of interradial scales on both dorsal and anal fin rays.

Gut simple, anal and anterior esophageal loops not adjacent; gut length may be greater than standard length; distance from last loop in gut to esophagus always less than 16% gut length. Genital papilla rounded, may be smaller than creased area of anus; pigmented only on base.

Suborbital streak wide, blunt-ended (usually not visible in preserved specimens). Stripe from snout to eye diffuse, rather a darkening at rim of orbit. Large, iridescent, metallic green-blue speckles on cheek in life, turning blackish in ethanol. Eyes bronze-bluish. Bars on sides sometimes doubled medially; lateral blotch oval, sometimes ocellated. About six unordered rows of spots on sides, larger than scales; breast bronzeblackish with green-blue tinge in life. Dots on fins large, dark blue. Axil of pectoral fin with a dorsal spot; base of pectoral fin whitish.

Distribution. Endemic to cenotes and small inland lakes in northern Quintana Roo, eastern Yucatan Peninsula, Mexico (Fig. 22).

Etymology. Latin gemmata, meaning “bejeweled,” in reference to the large, bright green and blue cheek and opercle spots in life. An adjective.

Remarks. The authorship of this species is joint with S. Contreras-Balderas, who independently collected and recognized it as distinct.