Archocentrus multispinosus ( Guenther , 1867 )

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 : 28-29

Archocentrus multispinosus ( Guenther, 1867)

Figures 1, 3

Heros multispinosus Guenther, 1867: 601 (original description).

Cichlasoma (Archocentrus) multispinosum , Jordan & Evermann 1898: 1525 ( new combination).

Herotilapia multispinosa , Pellegrin 1904: 211 ( new combination).

Archocentrus multispinosus , Burgess 2000: 54 ( new combination).

Holotype. BMNH 1865.7.20.34 , 68 mm SL (Fig. 3), J. M. Dow. Lake Managua , Nicaragua. No paratypes.

Diagnosis. Autapomorphies (Schmitter-Soto, in press): both upper and lower symphysial teeth tricuspid; basally two rows of interradial scales on anal fin; rostral arm of articular bone only a little longer than dorsal process (ratio ca. 0.87, vs. 0.77 or less in other Archocentrus ); gut with IP = 6. Also diagnosable from all other Archocentrus by a sigmoid (vs. irregular) posterior edge of urohyal; coronal pore triple (vs. single); narrowest point of dentigerous arm of premaxilla at caudal tip (vs. before tip). Truncate caudal-fin profile, synapomorphic with A. centrarchus (vs. rounded-truncate in A. spinosissimus ).

Description. D. XVIII-XIX,8-9; A. XI-XII,7-8; gill rakers on lower limb of first arch 8-9; gill rakers blunt, their ends trapezoidal, serrated. Scale rows on cheek 4-5 (contra Stawikowski & Werner 1998, who counted 3); pored lateral-line scales (not counting scales overlapping between the two segments of the lateral line) 27-29; 2.5 scales from lateral line to base of first dorsal-fin ray; circumpeduncular scales 19-21 (further meristic data appear in Table 3).

Largest examined specimen 87 mm SL. Body rather oval, usually not so deep (47-54% of SL) and not so symmetrical horizontally, the curve of the nape somewhat more pronounced than the curve of the thoracic region. Head profile straight above orbits, convex at nape. Head length 33-35% of SL; orbital diameter 26- 33 % of head length (other morphometric data appear in Table 4). Maxilla extending to ventral rim of orbit; premaxillary dorsal process not reaching anterior rim of orbit. Teeth not embedded; incisors tricuspid ( Pellegrin 1904: fig. 20, 4), symphysial teeth aligned with adjacent teeth. Lower jaw not protruding. Lower lip at corner of mouth square, not rounded, the angle varying from right-angled to acute. Frenum present on lower lip.

Pectoral fins reaching posteriorly to 3rd -5th anal-fin spine, and pelvic fins extending to 4th -6th anal-fin spine; distal pelvic ray may bear filaments. Filamentous rays of dorsal and anal fins extending to about proximal third of caudal fin. Caudal fin truncate (contra Günther 1869 and Pellegrin 1904, who considered it rounded). Scales strongly ctenoid. A few, sporadic subsidiary pored scales on caudal fin, not forming rows; scales between dorsal fin rays, proximally in two rows, the rows up to 14 scales long.

Gut strongly coiled, IP = 6. Genital papilla longer than wide (may be wider than long in females), widest at base, deeply notched, sunken; no pigmentation, except for base and sides.

A vertical bar on head; two interorbital bands; no suborbital streak; diffuse stripe from snout to eye; no speckles on cheek; a spot on opercle, which represents an anterior expansion of longitudinal stripe on side of body. Eyes orange. Seven sharp vertical bars on sides, broader than interspaces, and usually double; 1st bar diffusely Y-shaped; a longitudinal stripe from orbit to a circular, jet-black blotch on 4th bar; bars on side of body not extending onto dorsal fin. No ocellus on dorsal fin; dorsal and anal fins immaculate or with 3-4 rows of dots. About 12 rows of spots on sides, smaller than scales; breast region olive-yellowish. Axil of pectoral fin with same coloration as breast or dusky; base of pectoral fin with same coloration as breast or slightly paler. A black caudal blotch, on fin, across lateral line, the blotch not ocellated.

Distribution. Atlantic slope, from Costa Rica ( Río Matina) through the Great Lakes of Nicaragua to Honduras( Río Patuca); Pacific slope, from Costa Rica ( Río Tempisque) to Nicaragua ( Río Guasaule) (Fig. 1). Panamanian records (e.g. BMNH 1925.3.6.165) are based on misidentifications.

Remarks. Pellegrin (1904) put the species in a monotypic genus because of the “dentition tout à fait caracteristique ” (surprisingly not observed by Günther 1867 or 1869); on the other hand, he considered it “[v] oisin de Neetroplus .”

A . multispinosus exhibits striking and abundant autapomorphies, but its relationships to the other two Archocentrus are not resolved (Schmitter-Soto, in press). Considering this, it seems best to apply only one name to the monophyletic group formed by the three species.