Eviota rubriguttata, Greenfield, David W. & Suzuki, Toshiyuki, 2011

Greenfield, David W. & Suzuki, Toshiyuki, 2011, Two new goby species of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae), Zootaxa 2812, pp. 63-68 : 66-68

Eviota rubriguttata n. sp.

Redspotfin Pygmygoby

New Japanese name—Hanabi-Isohaze ( Figs. 4–6 )

Eviota sp. 15. Senou et al., 2004: 154 (underwater photograph, Iriomote-jima Island, the Ryukyu Islands, Japan, 6 m depth).

Holotype: OMNH-P35645, 13.2mm SL female, Japan, the Ryukyu Islands, Iriomote-jima Island, Uehara Beach, (24°25’57.16”N, 123°48’53.34”E), T. Suzuki & M. Suzuki, August 27, 1994.

Diagnosis. The following combination of characters distinguishes E. rubriguttata from congeners: cephalic sensory-pore system pattern group1 (complete); dorsal/anal fin-ray formula 8/7; pectoral-fin rays branched; anterior spines of first dorsal fin not elongated; female genital papilla non-fimbriate; 5th pelvic-fin ray absent; body relatively deep, 25% SL; no occipital spot or spots on pectoral-fin base; internal blotch over ural centrum above midline, faint when preserved; both dorsal fins and anal fin with small, distinct, round red spots when fresh; sides and belly peppered with tiny black chromatophores both when fresh and preserved.

Description. Dorsal-fin rays VI+I, 8; anal-fin rays I,7; pectoral-fin rays 17, lower 7 rays branched; pelvic fin I,4, 5th ray absent; branches on 4th pelvic-fin ray 6; 2 segments between branches; 14 branched caudal-fin rays; segmented caudal-fin rays 17; lateral scale rows 23; transverse scale rows 7; breast and pectoral-fin base scaleless; anterior spines of first dorsal fin not elongated; pelvic fins reaching to urogenital papilla; cephalic sensory-pore system pattern group 1 (complete); female urogenital papilla non-fimbriate.

Measurements. Head length 30.7; origin of first dorsal fin 39.4; origin of second dorsal fin 61.4; origin of anal fin 62.1; caudal-peduncle length 22.3; caudal-peduncle depth 15.9; body depth 25.0; eye diameter 10.2; snout length 5.3; upper-jaw length 10.6; pectoral-fin length 34.1; pelvic-fin length 29.5.

Color. Color of freshly collected female holotype, OMNH-P35645: ( Fig. 4 ). Body semitranslucent with a blue tinge, with six internal black bars spaced along vertebral column from pectoral-fin base to caudal-fin base. Dark internal bars extending dorsally from bars on vertebral column, similar bars extending ventrally from anal-fin origin to caudal-fin base. Posteriormost bar on caudal peduncle darker, a rectangular spot above midline, a separated dark spot on ventral surface below it. Abdomen orange, covered with a peppering of small black chromatophores. Head with a bluish tinge, overlaid by many redish brown reticulations that extend to ventral surface of head and onto the nape. Those on the nape forming bars across the head in advance of the dorsal fin. Entire head and body overlaid with a peppering of small black chromatophores. Dorsal, anal, and caudal fins dusky. First dorsal fin with four rows of distinct large red spots on the membranes. Second dorsal and anal fins with similar rows, but on the fin rays. Caudal fin without red dots. Rays of pectoral and pelvic fins dusky. Iris of eye golden with orange blotches, pupil black.

Color in life: ( Fig. 5 ) Head and body semitransparent overlaid by orange markings and orange scale pockets on sides. Internal markings dark orange and as in fresh specimen, but not as obvious. Many spots and reticulations on side and top of head, those on nape and under first dorsal fin distinct, wide bars with silver-white between them. Dorsal surface under dorsal fins with short orange bars, also separated by silver-white. Head and body overlaid with a peppering of small black chromatophores. Pectoral-fin base cream. Dorsal and anal fins crossed by rows of distinct red-orange spots. Iris of eye cream with spoke-like orange bars radiating from black pupil.

Color of holotype in preservative: ( Fig. 6 ) Head and body pale yellowish. No bold dark marks on body, internal mark over ural centrum barely visible. Snout, jaws, and nostrils without any dark marks. Side of head with many dark spots and reticulations extending from under eye back to opercular membrane. Those on top of head form four broad bands from behind eyes to dorsal-fin origin. Pectoral-fin base adjacent to opercular membrane peppered with small, black chromatophores, remainder of base with no markings. Sides, belly, breast, and under head peppered with small black chromatophores. Both dorsal and anal fins peppered with light brown chromatophores, distal margins of both dorsal fins with heavier peppering. Pectoral, pelvic, and caudal fins immaculate.

Distribution. Amami-oshima Island and Iriomote-jima Island, the Ryukyu Islands, Japan ( Senou et al., 2004; In this study).

Etymology. The specific epithet is an adjective combining the Latin ruber (red) and guttatus (spotted), referring to the distinctive red spots on the dorsal and anal fins.

Comparisons. Eviota rubriguttata belongs to the cephalic sensory-pore pattern group 1 (complete) of Lachner and Karnella (1980). With the addition of E. rubriguttata , the total number of species in this group is now 27 ( Greenfield & Randall, 2010b). Eviota rubriguttata has a dorsal/anal formula of 8/7 and branched pectoral-fin rays. The only other Eviota species in this group sharing those characters is E. pardalota Lachner and Karnella (1978) . Eviota pardalota has two distinct dark spots on the pectoral-fin base that are lacking in E. rubriguttata , as well as a series of 10 dark spots on the dorsum along the bases of the two dorsal fins to the caudal fin, also absent in E. rubriguttata .

Remarks. Eviota rubriguttata again presents an example of considerable differences in the coloration between preserved and fresh specimens and live individuals ( Greenfield and Randall, 2010a; Greenfield and Suzuki, 2010).

Figures

FIGURE 4. Freshly collected female holotype of Eviota rubriguttata, OMNH-P 35645. Photograph by Toshiyuki Suzuki.

FIGURE 5. Underwater photograph of Eviota rubriguttata, about 2 cm TL, Kasari-wan Inlet, Amami-oshima Island, the Ryukyu Islands, Japan, 9 m depth. Photograph by Hiroyuki Kanehara.

FIGURE 6. Preserved holotype of Eviota rubriguttata, OMNH-P 35645. Photograph by D. W. Greenfield.