Eviota flebilis, Greenfield, David W., Suzuki, Toshiyuki & Shibukawa, Koichi, 2014

Greenfield, David W., Suzuki, Toshiyuki & Shibukawa, Koichi, 2014, Two new dwarfgobies of the genus Eviota from the Ryukyu Islands, Japan (Teleostei: Gobiidae), Zootaxa 3774 (5), pp. 481-488 : 482-484

Eviota flebilis n. sp.

Tearful Dwarfgoby

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

Eviota sp. 3. Suzuki et al., 2004: 143 (underwater photographs, Iriomote-jima Island, the Ryukyu Islands, Japan, 4 and 6 m depth).

Holotype. NSMT-P 114944, 10.1 mm, male, Nakana, Iriomote-jima Island, the Ryukyu Islands, Japan, 24.4341N, 123.7905E, 5-8 m depth, field number S-18758, Toshiyuki Suzuki, Koichi Shibukawa, Masatomi Suzuki & Akira Kawai, 14 August 2010.

Diagnosis. The following combination of characters distinguishes E. flebilis from congeners: cephalic sensory-pore system pattern 2 (lacking only IT pore); dorsal/anal fin-ray formula 8/7; pectoral-fin rays unbranched; 5th pelvic-fin ray 12.9% of 4th; red-orange blotches running along the vertebral column, a distinctive narrow, redorange line under the eye, and a dark vertical line at the caudal-fin base.

Description. Dorsal-fin rays VI–I, 8; anal-fin rays I,7; dorsal and anal soft rays branched except first, the last ray branched to base; pectoral-fin rays 15, all unbranched, fin reaching to third anal-fin ray base; pelvic fins joined by membrane only at extreme base, no pelvic frenum, pelvic-fin membrane reduced, pelvic-fin rays I,5, 4th pelvicfin ray with 5 branches, 1 segment between branches, 5th segmented pelvic-fin ray 12.9% of 4th ray, pelvic fins reaching to second anal-fin ray base; 11 branched caudal-fin rays, segmented caudal-fin rays 17; lateral scale rows 22, transverse scale rows 5, no scales on head, nape, breast, pectoral-fin base, midline of belly and wide areas along bases of dorsal fins, scales on body finely ctenoid; vertebrae 10 + 15 = 25; first dorsal-fin spine filamentous, extending back to base of 2nd soft ray of second dorsal fin; cephalic sensory-pore system pattern 2 lacking only the IT pore: anterior oculoscapular canal with pores B', single C, single D, E and F', two preopercular-canal pores, N' and O'; male genital papilla non-fimbriate, reaching beyond anal-fin origin; mouth oblique, lower jaw slightly projecting, maxilla extending beyond a vertical at posterior margin of pupil; anterior tubular nares long, extending to upper lip and light in color; gill opening extending forward to a vertical at midway between edge of preoperculum and posterior end of opercular membrane, gill membranes attached anteriorly to isthmus, without a free fold.

Measurements. Standard length 10.1 mm; Head length 33.5; origin of first dorsal fin 38.7, above posterior end of pectoral-fin base; origin of second dorsal fin 58.1; origin of anal fin 61.3, a vertical through 1st soft ray of second dorsal fin; caudal-peduncle length 25.5; caudal-peduncle of moderate depth 12.3; body slender, its depth 17.0; eye diameter 9.4; snout length 6.1; upper-jaw length 14.2; pectoral-fin length 32.1; pelvic-fin length 34.0.

Color in preservative of holotype ( Fig 1 ). Body translucent white with internal markings corresponding to red-orange markings in fresh specimen visible. Clusters of chromatophores on ventral surface of body at bottom in internal marks. Abdomen with scattered chromatophores from behind pectoral-fin base following alimentary canal to anus. Cluster of larger chromatophores behind eye, three large chromatophores under eye at location of narrow red-orange line in fresh specimen. Scattered chromatophores at anterior end of jaws, and cluster of chromatophores on isthmus. First dorsal fin clear except for five dark marks on first spine. Second dorsal fin clear except for scattering of chromatophores on distal third. Anal fin heavily pigmented. Distinct vertical line of chromatophores at caudal-fin base. Caudal fin clear with scattered chromatophores at distal and lower margins. Pectoral and pelvic fins translucent.

Color of fresh holotype ( Fig. 2 ). Body translucent with series of seven red-orange blotches spread along vertebral column: first just posterior to pectoral-fin base in advance of first dorsal fin; second under center of first dorsal fin; third at end of first dorsal fin; fourth under elements two, three, and four of second dorsal fin; fifth under last three elements of second dorsal fin; sixth and seventh spaced along caudal peduncle. Abdomen dusky with three red-orange blotches, each behind three smaller blotches above vertebral column. Ventral blotches four through seven each with narrow red-orange lines extending down to ventral surface of body: fourth with single line; fifth with two lines; sixth with two lines but posteriormost line joining anteriormost line of the two extending down from seventh blotch. Spaces between these narrow lines appearing as six distinct light spots. Single narrow, vertical red-orange line with few chromatophores across caudal-fin base. Narrow yellow line extending up from vertebral blotches to dorsal surface, similar to those below blotches. Upper half of side of head and pectoral-fin base red-orange, lower half of head, jaws, and nares yellow overlaid with small red-orange spots. Distinctive narrow red-orange line extending down from under eye to posterior end of jaws. Eye with black pupil surrounded by yellow iris with scattered red-orange markings. Interorbital area and top of head behind eyes translucent with scattered chromatophores behind eye. Red-orange area extending up from side of head to top of head behind translucent area. Nape with few red-orange spots and faint yellow bars. Bases of first and second dorsal fins with yellow on membranes. First dorsal spine with five red-orange spots spaced along its length, the distal end bluish. Remaining spines of first dorsal fin with slight reddish tinge. Second dorsal fin with a row of red-orange spots across center of fin. Distal third of second dorsal fin with yellow on membranes overlaid with small bluish dots concentrated on distal margin. Anal fin heavily peppered with yellow and bluish dots. Caudal fin clear, crossed by three rows of red dots, distal margin with some yellow and peppering of bluish dots. Pelvic and pectoral fins translucent.

Color in life ( Fig. 3 ) ( Suzuki et al., 2004: 143). Body translucent with red and white markings. Red extending down the vertebral column separated by seven white marks on dorsal part of column. Narrow red lines extending down from vertebral column posterior to abdomen. Abdomen, cheek, and top of head red with white spots of various sizes. Series of eight roundish progressively smaller white spots running from pectoral-fin base along ventral surface of side to caudal-fin base. Three or four small white spots on cheek and more on top of head. Lower half of head translucent overlaid with peppering of chromatophores. A distinctive narrow red line extending ventrally from under eye to posterior end of jaws. Pupil of eye black surrounded by yellow iris with red areas, small yellow-white dots on red at top of iris. Caudal-fin base with distinct vertical dark mark, sometimes extending anteriorly as small triangle. Membranes of dorsal, anal, and caudal fins appear peppered with dark pigment. Dark marks present on filamentous first spine of male.

Distribution. Amami-oshima Island, Kerama Islands and Iriomote-jima Island, the Ryukyu Islands, Japan ( Suzuki et al., 2004). Has been photographed or taken from lagoon, slope, and drop-off coral-reef habitats.

Etymology. The specific epithet is from the Latin flebilis (tearful) referring to the distinctive tear-like red line under the eye, and is treated as a noun in apposition.

Comparisons. Eviota flebilis belongs to the cephalic sensory-pore pattern 2 of Lachner and Karnella (1980), lacking only the IT pore. The group contains 30 described species ( Greenfield & Winterbottom, 2014, Table 1), increasing to 31 with the addition of E. flebilis . It differs from species in cephalic sensory-pore pattern 2 as follows: the following species have branched pectoral-fin rays whereas they are unbranched in E. flebilis – E. afelei Jordan & Seale, E. bimaculata Lachner & Karnella , E. dorsimaculata Tornabene, Ahmadia , & Williams, E. hinanoae Tornabene, Ahmadia , & Williams, E. hoesei Gill & Jewett , E. indica Lachner & Karnella , E. japonica Jewett & Lachner , E. latifasciata Jewett & Lachner , E. lacrimosa Tornabene, Ahmadia , & Williams, E. pellucida Larson , E. piperata Greenfield & Winterbottom , E. prasina (Klunzinger) , E. punctulata Jewett & Lachner , E. queenslandica Whitley , E. rubra Greenfield & Randall , E. saipanensis Fowler , E. tigrina Greenfield & Randall , E. variola Lachner & Karnella , and E. zonura Jordan & Seale; from those with unbranched pectoral-fin rays by having a dorsal/anal fin-ray formula of 8/7 whereas, E. sigillata Jewett & Lachner , E. spilota Lachner & Karnella , and E. zebrina Lachner & Karnella usually have values of 9/8 or 9/7, and from E. cometa Jewett & Lachner , which can have 9/8 or 8/7, by lacking an obvious black spot before the caudal fin; from those with dorsal/anal values of 8/7 by having a shorter 5th pelvic-fin ray, 12.9% the length of the 4th ray, (longer, modally 40% in E. pellucida and E. prasites Jordan & Seale); and from E. storthynx Rofen , with shorter 5th pelvic-fin rays, by lacking the dark occipital spot present in that species. The only other described species of Eviota sharing characters with E. flebilis are E. ancora Greenfield & Suzuki , and E. springeri Greenfield & Jewett. Eviota ancora is a species that has a hook-shaped orange coloration on the side of the head, the caudal fin has five irregular bands of circles of small, dark chromatophores on larger red spots crossing the fin; and lacks the red-orange blotches running along the vertebral column that are present in E. flebilis , the distinctive narrow, red-orange line under the eye, and the dark vertical line at the caudal-fin base. Eviota springeri has a large dark spot medially at the end of the caudal peduncle that is lacking in E. flebilis .

Figures

FIGURE 1. Preserved holotype of Eviota flebilis NSMT 114944. Photograph by Toshiyuki Suzuki.

FIGURE 2. Freshly collected holotype of Eviota flebilis, NSMT 114944. Photograph by Koichi Shibukawa.

FIGURE 3. Underwater photograph of Eviota flebilis. Photograph by Korechika Yano.