Elacatinus redimiculus, Taylor, Michael S. & Akins, Lad, 2007

Taylor, Michael S. & Akins, Lad, 2007, Two new species of Elacatinus (Teleostei: Gobiidae) from the Mexican coast of the Gulf of Mexico, Zootaxa 1425, pp. 45-51 : 48-50

Elacatinus redimiculus , sp. nov.

Cinta Goby

Figures 3,4

Type series: Holotype: UF 162595, La Banquilla Reef, Gulf of Mexico, Veracruz, Mexico; 19°13.39'N, 96°05.71'W; 16 July 2005. Paratypes: UF 162596 (2 specimens), same as holotype.

Diagnosis: Elacatinus redimiculus can be distinguished from other species of Tigrigobius by the reddish orange blotches or broken bands on the head and the 13 reddish orange to dark brown bands between the pectoral fin and caudal fin.

Description: Morphometrics of all type specimens (15.1–17.0 mm SL) as a percent of standard length (mean): head length, 26.2–28.5 (27.4); body depth at dorsal origin, 18.5–21.8 (19.8); caudal peduncle depth, 10.1–12.4 (11.2); eye diameter, 7.1–7.9 (7.6); snout length, 5.9–6.6 (6.2); upper jaw length, 9.3–11.9 (10.6); pectoral fin length, 25.9–32.5 (29.6); pelvic fin length, 18.2–23.8 (20.2); caudal fin length, 16.5–25.2 (21.8). Fin ray counts: D. VII, 11; A. 9–10 (mode = 9); P. 17.

FIGURE 4. Live individuals of Elacatinus redimiculus illustrating rocky and coral habitat, Veracruz, Mexico. Photographs by Lad Akins.

The body is elongate, laterally compressed, and naked except for usually 4 basicaudal ctenoid scales, arranged typically in a single, vertical row on each side of the peduncle. One specimen has a fifth scale in a second row on the right side, and another specimen has two scales on the left ventral half of the peduncle, and none dorsally. The tongue is bilobed. The conical teeth are arranged in a single row, but males have enlarged, recurved canines. Males also possess an elongated first dorsal spine. Males have a slender, conical genital papilla; females have a blunt papilla.

Coloration: In life (Fig. 4), the body is a translucent straw color. Internally, alternating black and white dashes extend along the midline from the operculum to the caudal peduncle. The gut is marked by two large, black blotches. The posterior blotch is surrounded and separated from the anterior blotch by bright white. A duller white coloration extends anteriorly from below the anterior blotch throughout the head. Externally, the face, lips, cheeks and operculum are marked with reddish-orange blotches or broken bands. The posterior cephalic region is marked by two reddish orange bands that drape from the nape down along the sides of the head. The first occurs approximately midway between the eyes and the origin of the first dorsal fin. This band drapes across the center of the operculum and merges with a reddish orange opercular spot. The second band occurs just anterior to the first dorsal origin and descends the side anterior to the pectoral fin, and reaches as far as the pectoral fin insertion. Posterior to the pectoral fin, the body is marked by 13 equally spaced bands that grade from dull, orange-tan anteriorly to dark brown bands posteriorly. Anterior to the second dorsal fin, the bands are restricted to the dorsum and sides, but completely encircle the body posterior to the origin of the second dorsal fin. The bands are thin, with the intervening space approximately twice the width of a single band.

In preservative, the dark bands of the body are clearly evident. The bands are somewhat thicker on the dorsal surface of the fish, but are otherwise thinner on the lateral and ventral surfaces. The space between bands is lightly covered with tiny melanophores. The head is evenly covered with scattered large melanophores. Denser concentrations of melanophores represent the orange markings found on the head.

Comparisons: The combination of a banded body, and basicaudal scales on an otherwise completely unscaled body places E. redimiculus in the subgenus Tigrigobius ( Böhlke and Robins 1968) . Elacatinus redimiculus joins E. macrodon as the only species of Tigrigobius reported from the Gulf of Mexico. Further, these two species are most similar in color and morphology. However, the banding pattern of E. macrodon continues onto the head as distinct bands or bars, while the head of E. redimiculus is decorated with blotches and broken bands, differences that are apparent even in preserved specimens. The only other Tigrigobius that may confuse identification is E. zebrella (Robins) , but the latter species has broad bands that are nearly equal in size to the intervening pale zone ( Robins 1958), and is known only from the southern Caribbean Sea.

Distribution: Elacatinus redimiculus is known only from the western Gulf of Mexico reef systems within the Veracruz Marine Park. Specimens were observed on reefs as far north as Isla De Lobos (21°29.36'N, 97°13.53'W) and south to Isla Verde off Veracruz (19°11.88'N, 96°04.12'W).

Etymology: The specific name, redimiculus , refers to ribbons that were sometimes attached to the side of a headdress then passed over the shoulders to drape across each side of the breast, or decoratively woven or plaited into hair. We apply this name as an adjective to describe the reddish-orange bands or “ribbons” that drape down across the nape and anterior trunk of this goby. The common name, cinta, is Spanish for ribbon.

Remarks: Elacatinus redimiculus was typically found on brightly illuminated surfaces of either living Colpophyllia natans or algae encrusted covered coral remnants in shallow waters between 3–8 m depth (Fig. 4). Most specimens observed were not inclined to move before an extremely close approach. Once disturbed, individuals would move rapidly a short distance (less than 50 cm) across the substrate, before returning to a stationary position. After repeated disturbances, individuals would retreat into the cover of small holes, crevices or the underside of eroded corals. Feeding behavior was not observed, though it would be anticipated to approximate that of other Tigrigobius species. No cleaning or reproductive behavior was noted.