Eviota flavipinnata, Suzuki, Toshiyuki, Greenfield, David W. & Motomura, Hiroyuki, 2015

Suzuki, Toshiyuki, Greenfield, David W. & Motomura, Hiroyuki, 2015, Two new dwarfgobies (Teleostei: Gobiidae) from the Ryukyu Islands, Japan: Eviota flavipinnata and Eviota rubrimaculata, Zootaxa 4007 (3), pp. 399-408 : 400-404

Eviota flavipinnata n. sp.

Yellow-fin Dwarfgoby

New Japanese-name: Kibire-Isohaze ( Figs. 1–3 )

Eviota sp. 3. Suzuki 2014: 516 (Yoron Island, the Ryukyu Islands, Japan).

Holotype. NSMT-P 110502, 16.6 mm, female, off Chabana Fishing Port, Yoron Island, the Ryukyu Islands, Japan, 27°03ʹ40ʹN, 128°25ʹ02ʺE, KAUM Fish Team, 21 Aug. 2012.

Diagnosis. A species of Eviota with cephalic sensory-canal pore system pattern 2 (lacking only H [IT] pore); some pectoral-fin rays branched; dorsal/anal fin-ray formula 9/8; 5th pelvic-fin ray 12% of 4th ray; no prominent distinct dark spots on pectoral-fin base; no caudal-peduncle spot over preural centrum; no prominent occipital spots; no strong, dark spots on caudal fin; two dark spots over anal-fin base; dorsal fins golden-yellow and anal fin red when fresh.

Description. Dorsal-fin rays VI-I,9, first dorsal fin triangular in shape, first spine longest but all spines not filamentous, not extending back to origin of second dorsal fin, all second dorsal-fin soft rays branched except first soft ray, the last ray branched to base; anal-fin rays I,8, 4-8th soft rays branched, the last ray branched to base; pectoral-fin rays 16, 11-16th rays branched, pectoral fin reaching to above third anal-fin soft ray base; pelvic fins without basal membrane, no pelvic frenum, pelvic-fin membrane reduced, pelvic-fin rays I,5, 4th pelvic-fin ray with 4 branches, 3 segments between branches, 5th segmented pelvic-fin ray unbranched, 12% of 4th ray in length, pelvic fins reaching to second anal-fin soft ray base; 12 branched and 17 segmented caudal-fin rays; lateral scale rows 24, transverse scale rows 6, no scales on head, nape, breast, pectoral-fin base, and narrow areas along anterior half of first dorsal-fin base, scales on body finely ctenoid except belly where they are cycloid; cephalic sensorycanal pore system pattern 2 (lacking only the H (IT) pore): anterior oculoscapular canal with pores B', single C, single D, E and F', two preopercular-canal pores, N' and O'; female genital papilla smooth, cylindrical, with six short finger-like projections on end, not reaching to anal-fin origin; mouth oblique, both jaws equal, maxilla extending posterior to vertical at anterior half of pupil; anterior nares tube not extending to upper lip and dark in color; gill opening extending forward to below posteroventral edge of operculum, gill membranes attached anteriorly to isthmus.

Measurements. Standard length 16.6 mm; head length 31.4; origin of first dorsal fin 36.0, above posterior end of pectoral-fin base; origin of second dorsal fin 58.3; origin of anal fin 60.6, at vertical through second soft ray base of second dorsal fin; caudal-peduncle length 24.0; caudal-peduncle depth 12.6; body depth 20.0; eye diameter 9.1; snout length 6.6; upper-jaw length 11.4; pectoral-fin length 31.4; pelvic-fin length 33.1.

Color in preservative of holotype ( Figs. 1 & 2 ). Background color of head and body pale yellow, side of head and ventral half of body from anal-fin origin to caudal fin lighter, almost white. Sides and top of head with widely spaced small black chromatophores, a concentration of brown chromatophores on upper and lower jaws. Iris of eye black, pupil clear. Pectoral-fin base sprinkled with small brown chromatophores, a concentration of larger brown chromatophores across its center. Nape peppered with small black chromatophores. Scale edges on upper half of body with brown chromatophores forming a diamond pattern. Abdomen with an orange tinge with a few scattered brown chromatophores. Ventral margin of body with five dark blotches (extensions of subcutaneous bars) two over anal-fin base and three on caudal peduncle. A fine black line along midline of body from anal-fin origin to caudalfin base. Lower half of pectoral fin with rows of dark chromatophores extending along rays about one-tenth of fin length, remainder of fin immaculate. First dorsal fin heavily peppered with dark chromatophores, larger brown ones on basal half of fin, smaller ones distally. Second dorsal fin and anal fin entirely peppered with small black chromatophores. Caudal fin with small black chromatophores on distal margins. Pelvic fins immaculate.

Color of fresh holotype ( Fig. 3 ). Background color of head and body translucent white. Dark chromatophores on head and body as described for preserved specimen. Pupil of eye black, iris bright red with black spokes radiating out from pupil. Snout and jaws orange with a yellowish tinge. An orange blotch under eye at six o’clock position, smaller blotch behind eye at four o’clock, a line extending back from eye at two o’clock position, and another behind jaws. Cheek out to edge of preoperculum white with a wash of pink, operculum with more orange. Nape mostly white with a wash of yellow-orange. Pectoral-fin base with two red-orange blotches, one dorsal and one ventral, separated by diagonal row of larger dark chromatophores. Body crossed by six orange subcutaneous bars, becoming less distinct posteriorly, first under first four spines of first dorsal fin, second under fifth and sixth spines, third at front of second dorsal fin, fourth under posterior half of fin, fifth and sixth crossing caudal peduncle. Distinct dark blotch at base of second bar at anal-fin origin, second at end of anal fin, three more on caudal peduncle, followed by red spot just before caudal-fin base. Side of body with wash of yellow over orange body bars. Scales on upper half of body darker orange. Ventral side of head and abdomen white. First dorsal fin bright yellow sprinkled with small black spots, smaller and more dense distally, first dorsal spine with three red sections separated by white, bases of remaining spines red. Second dorsal fin similar to first. Anal fin bright orange. Caudal fin with orange-yellow at base, yellow orange wash on fin with dark distal margins. Pectoral fin white with dark chromatophores as described for preserved specimen. Pelvic fins white.

Distribution. Yoron Island, the Ryukyu Islands, Japan (Suzuki 2014; in this study).

Etymology. The specific epithet is an adjective from the Latin flavus (golden-yellow) and pinna (fin) in reference to E. flavipinnata ’s golden-yellow fins.

Comparisons. Eviota flavipinnata has a cephalic sensory-canal pore pattern 2 (lacking only the H [IT] pore) and branched pectoral-fin rays. Thirty three species of Eviota share cephalic sensory-canal pore pattern 2, but only 20 have branched pectoral-fin rays (Table 1).

Of these, eight species have a dorsal/anal-fin formula of 8/8, whereas the new species has 9/8: E. dorsimaculata , E. indica , E. lacrimosa , E. latifasciata , E. piperata , E. rubra , E. shibukawai , E. specca . These further differ from the new species with E. dorsimaculata , E. indica , E. lacrimosa , and E. latifasciata , having dark spots over the ural centrum (vs. absent); E. lacrimosa , E. piperata , and E. specca have dark spots on the pectoralfin base (vs. absent); and E. rubra has a fimbriate urogenital papilla (vs. non-fimbriate). Thus even if the dorsal/ anal-fin formula varied to 9/8, E. flavipinnata still would be separated from these species.

Ten species have a dorsal/anal-fin formula of 9/8 as does the new species (Table 1): E. afelei , E. bimaculata , E. hoesei , E. hinanoae , E. japonica , E. prasina , E. punctulata , E. queenslandica , E. saipanensis , and E. zonura . All of these species have either a dark spot over the ural centrum (vs. absent) or dark spots on the pectoral-fin base (vs. absent), or both, except E. afelei , E. bimaculata and E. punctulata . Eviota afelei and E. punctulata have three dark marks over the anal-fin base (vs. only two). Eviota punctulata has a caudal fin covered with strong dark spots (vs. none or a few light spots) and edges of the scale pockets darkly pigmented (vs. not darkly pigmented). Eviota bimaculata has two dark, prominent occipital spots (vs. absent). Fresh coloration of E. flavipinnata differs greatly from that of E. bimaculata ( Fig. 4 ), and E. punctulata ( Fig. 5 ). Fresh coloration of E. afelei from Samoa, the type locality, is not known, but a photograph taken by J.E. Williams of a specimen thought to be that species from Moorea ( Fig. 6 ) also differs from E. flavipinnata .

Both E. tigrina and E. variola have a dorsal/anal-fin formula of 10/9 (vs. 9/8), E. variola has a fimbriate urogenital papilla (vs. not fimbriate), E. tigrina has the edges of the scale pockets darkly pigment and a dark, crescent-shaped bar over tips of hypurals (vs. absent). None of the other described species of Eviota have the conspicuous yellow dorsal fins and the orange anal fin found in E. flavipinnata .

TABLE 1. Species of Eviota included in the cephalic sensoy-canal pore system patten 2 (H[It] missing) with banched pectoral-fin rays: dorsal/anal-fin formulas (D/A); 5th pelvic-fin ray rudimentrary or absent (5th); uogenital papilla typefimbiate (F), cup-like (C), unmarked is smooth; dark spot over ural centrum (CS); dark spot or spots on pectoral-fin base (PS).

Species D/A 8/8 D/A 9/8 D/A 10/9 5th F C CS PS E. dorsimaculata x x E. indica x x E. lacrimasa x x x E. latifasciata x x x E. piperata x x E. rubra x x

E. shibukawai x x E. specca x x E. afelei x x E. bimaculata x

E. hoesei x x x E. hinanoae x x x x E. japonica x x E. prasina x x x x E. punctulata x

E. queenslandica x x E. saipanensis x x x E. zonura x x x x x E. tigrina x

E. variola x x x x E. flavipinnata x x E. rubrimaculata x

Figures

FIGURE 1. Eviota flavipinnata, preserved holotype, NSMT-P 110502, light background. Photograph by Toshiyuki Suzuki.

FIGURE 2. Eviota flavipinnata, preserved holotype, NSMT-P 110502, dark background. Photograph by Toshiyuki Suzuki.

FIGURE 3. Eviota flavipinnata, freshly collected holotype, NSMT-P 110502, dark background. Photograph by KAUM Fish Team.

FIGURE 4. Eviota bimaculata, freshly collected specimen, Jurien Bay, Australia. Photograph by J. B. Hutchins.

FIGURE 5. Eviota punctulata, freshly collected specimen under water, Fiji. Photograph by J. E. Randall.

FIGURE 6. Eviota afelei, freshly collected specimen, Moorea. Photograph by J. T. Williams.