IDENTIFICATION Head Pores - Cephalic head canals with pores B',C,D,E,F,H'; preopercle pores M',N,O', occasionally only two pores, may vary between the left and right sides Scales - Four, sometimes 5-6 basicaudal scales present; transverse scales-4-6; lateral scale rows 25-28; caudal peduncle completely scaled; scales extending forward on body in a narrow wedge, becoming reduced to 2 rows near base of pectoral fin

Fins - D1-7, first two spines filamentous in males; D2-11-12 generally 11; pectoral 16-18 generally 17; anal 9-10 generally 10; caudal rounded with 17 segmented rays; pelvic I,5 all rays branched, complete disk with well developed frenum, slightly linger than 1/2 distance to anus.

Head - Rounded with distinct dark bars under the eye and on the cheek.

Papillae - Transverse pattern; three rows before anterior of row b; row 5s/5i/6i continuous attached to the anterior of row b and extending below the level of row d; row d continuous; rows 1,2,3 not extending below row d.

Color - Distinct vertical dark bands on body; head with two dark bars from eye to ventral surface of head; two transverse dark bars on cheek.

Distribution - Found in the Panama Canal from the Atlantic coast to Miraflores locks (Van Tassell and Thorsen)

Habitat - Found in low salinity waters of the Panama Canal, inhabits rock crevices.

Notes - Recent collections by Van Tassell and Thorsen (July-August 2000) showed a maked reduction in the population of this species. No specimens were collected in Gatun Lake or the Atlantic side of the Canal where large numbers had been collected previously. This may be due to the introduction of chichlid into those areas for fishing.