Geophagus

López-Fernández, Hernán & Taphorn, Donald C., 2004, Geophagus abalios, G. dicrozoster and G. winemilleri (Perciformes: Cichlidae), three new species from Venezuela, Zootaxa 439, pp. 1-27 : 23

Key to the Venezuelan species of Geophagus

1 Infraorbital stripe complete ( Fig. 1 ), extending from ventral edge of orbit to edge of preopercule or dorsal half of interopercule ................................................................. 2

­ Infraorbital stripe absent, or reduced to a dark mark on preopercule ( Fig. 1 ) .............. 3

2 Dorsal fin base with sheath of scales; faint horizontal stripes on flank G. taeniopareius

­ Dorsal fin base without sheath of scales; no horizontal markings on flank ................... ........................................................................................................... G. grammepareius

3 Base of gill filaments on first gill arch largely covered by broad flap of skin; no discernible lateral bars on preserved specimens ( Fig. 2 e); Cuyuní river drainage ............. ........................................................................................................... G. brachybranchus

­ Base of gill filaments on first gill arch narrowly covered with skin at base; 4 to 7 lateral bars on preserved specimens; Orinoco or Río Negro drainages .......................... 4

4 Seven dark bars on flank, with bars 4 and 5 forming a “ Y ” pattern; ventral margin of caudal peduncle contained 1.1 to 1.3 times in dorsal margin of caudal peduncle; subopercule caudoventrally naked ( Fig. 2 a).................................................... G. dicrozoster

­ Fewer than seven bars on flank; ventral margin of caudal peduncle contained 1.5 to 1.6 times in dorsal margin of caudal peduncle; subopercule fully scaled ......................... 5

5 Dorsal lobe of caudal fin with accessory lateral line extension between rays D3 and D4; preopercular mark present; four, broad and parallel, caudo­ventrally inclined lateral bars on flank ( Fig. 2 c) ....................................................................... G. winemilleri

­ Dorsal lobe of caudal fin without accessory lateral line extension; preopercular mark absent; six, vertical and parallel bars on flank ( Fig. 2 b) ................................ G. abalios

Figures

FIGURE 1. Diagrammatic representation of scale nomenclature, head markings and lateral bar patterns of Geophagus as used in this paper. Abbreviations are as follows: E 1, first epaxial longitudinal series of scales, used to count number of longitudinal scales; E 6, last epaxial longitudinal series of scales; H 1 – H 5, hypaxial longitudinal series of scales; IOS, infraorbital stripe; MLS, midlateral spot; POM, preopercular mark; ULL, upper lateral line; LLL, lower lateral line; 1 – 7, lateral bars. Scale nomenclature after Kullander (1992, 1996). Infraorbital, preopercular and mid­lateral black markings are observable both in live and preserved specimens; lateral bar patterns are gener­

FIGURE 2. Diagrammatic representation of preopercular markings and lateral bars distinguishing Geophagus species within the G. surinamensis complex. a, G. dicrozoster, n. sp.; b, G. abalios n. sp.; c, G. winemilleri n. sp.; d, G. brokopondo; e, G. brachybranchus; f, G. s u r i n a m e n s i s; g, G. proximus; h, G. megasema; i, G. camopiensis, and j, G. altifrons. Preopercular markings are visible in both live and preserved individuals; lateral bar patterns are generally visible only in preserved specimens.