Eviota asymbasia, Greenfield, David W. & Jewett, Susan L., 2016

Greenfield, David W. & Jewett, Susan L., 2016, Two new dwarfgobies from the Indian and Western Pacific Oceans (Teleostei: Gobiidae: Eviota), Zootaxa 4121 (5), pp. 589-599 : 590-594

Eviota asymbasia n. sp.

Inconsistent Dwarfgoby Figs. 2–4

Holotype. USNM 229476, 15.0 male, Philippine Islands, Palawan Province, Cuyo Id., 1 m, field number SP 78-17, 21 May 1978, V.G. Springer & team.

Paratypes. All from Philippine Islands. USNM 437288, 14.6 female, 4 males 12.7–14.1, taken with holotype; CAS 238219, 2 males 14.0, 2 females 13.5–14.0. taken with holotype; ROM 101093, 12.0 female, 2 males 11.6– 11.7, Barain Id, 0–13.7 m, SP 78-20, 23 May 1978, V.G Springer & team; USNM 229470, 16.8 male, Solino Id, 0– 4.6 m, LK 79-7, 3 May 1979, L. Knapp et al.; USNM 229471, 14.8 male, Tagauayan Id., 0–10 m, SP 78-7, 10 May 1978, V.G. Springer & team; USNM 229473, 15.1 female, 3 males 13.4–14.2, Putic Id., 0–4.6 m, SP 78-18, 22 May 1978, V.G. Springer & team; USNM 229475, 12.0 female, Siquijor Id., 0–6 m, SP 18-4, 9 May 1978, V.G. Springer & team; USNM 229477, 12.2 female, Siquijor Id., 0–10 m, SP 78-7, 10 May 1978, V.G. Springer & team.

Non-type material examined: USNM 229462 (2), Indonesia, Karimjundjawa Id.; USNM 229468 (5), Indonesia, N. of Mendjaagan Id.; USNM 229469 (1), Indonesia, Bawean Id.; CAS 238223 (1), Terbamg Selatan, Damar.

Diagnosis. The following combination of characters distinguish E. asymbasia from congeners: cephalic sensory-pore system always lacking the IT, and usually the POP, but occasionally the POP is present on both or only one side of the head, a dorsal/anal-fin formula of 8/8, some pectoral-fin rays branched and usually 15 rays, two spots on the pectoral-fin base, no dark spot over the preural centrum, first dorsal fin may be filamentous, six ventral postanal spots, and the male genital papilla is not fimbriate.

Description. Dorsal-fin rays VI+I,8 [all], first dorsal fin triangular in shape, first two spines of first dorsal fin may be filamentous in males, extending back to 3rd ray of second dorsal fin in holotype, may also be filamentous in females; anal-fin rays I,8 [all], all soft rays branched, last ray branched to base; pectoral-fin rays 15 (13[1], 14 [2], 15 [16], 16 [1],17[12]), some rays branched; fifth pelvic-fin ray about 10% of 4th ray (pelvics broken in most types); 12 branched and 17 segmented caudal-fin rays; 24 lateral scale rows, transverse scale rows 6, area under first half of dorsal fin naked, scales on body finely ctenoid, midline of abdomen with cycloid scales; genital papilla in male smooth, not fimbriate, tapered with fringed tip, extending to anal-fin spine; female genital papilla short and rounded with smooth sides, several short finger-like projections on the end; body moderately slender, front of head rounded with an angle of about 60° from the horizontal axis; mouth oblique, forming an angle of about 65° to horizontal axis of body, lower jaw not projecting; maxilla extending to front of pupil; anterior naris tube short, just reaching to edge of upper lip; gill opening extending forward to posteroventral edge of preoperculum; cephalic sensory-pore system pattern always lacking the IT, and usually the POP, but occasionally the POP is present on both or only one side of the head. Of 21 specimens examined, 16 lacked both the IT and POP, 4 lacked the IT but had the POP on both sides, and one lacked the IT but had the POP on one side. The holotype has POP pores on both sides, but they are close together and near the center of the canal ( Fig. 2 ).

Measurements (based on holotype and 8 paratypes, 13.5–15.0 mm). Head length 31.0 (30.0–32.1, 30.9); origin of first dorsal fin 36.0 (33.6–37.8, 36.1), lying behind posterior margin of pectoral-fin base; origin of second dorsal fin 57.0 (57.0–60.0, 58.2), slightly in advance of anal-fin origin; origin of anal fin 60.7 (58.6–61.4, 60.3); caudal-peduncle length 23.3 (23.3–27.0, 25.0); caudal peduncle moderate depth 14.0 (11.1–14.0, 12.5); body depth 21.3 (20.7–26.1, 22.2); eye diameter 9.7 (9.6–11.8, 10.7); snout length 4.7 (3.6–5.6, 5.2); pectoral-fin length (all broken); pelvic-fin length (all broken).

Color in preservative of holotype ( Fig. 3 ). Background color of head and body pale yellow. Head and body with peppering of small brown chromatophores. Blotch of brown chromatophores on operculum, centered behind edge of preoperculum, second concentration behind lower preopercular edge. Three distinct bars under eye: first at 8 o’clock position extending down across jaws; second at 6 o’clock extending down under head; third at 4 o’clock, a short rounded blotch. Scattered brown blotches behind center of eye extending back across top of operculum. Pupil of eye clear, iris gray. Three dark brown lines on top of head spaced between back of eyes and first dorsal-fin origin. Naris tubes brown. Pectoral-fin base with two brown blotches, one dorsal and one ventral. Scale pockets on body lightly lined with small brown chromatophores. Thin dark line running along middle of sides of body. Six obvious, dark, ventral postanal midline spots followed by a smaller spot at caudal-fin base, matched by a similar spot at top, these two not counted as postanal spots. Filamentous spine of first dorsal fin with a series of spaced brown spots, remainder of fin peppered with small brown spots, lighter area at center. Second dorsal and anal fins peppered with dark chromatophores and melanophores. Pectoral, pelvic, and caudal fins lighter than other fins.

Color of fresh specimen from Damar ( Fig. 4 ). Background color of head and body translucent gray. Body with white line along vertebral column from above pectoral-fin base, over abdomen bifurcating to one line above and one below column. Three wide triangular light brown bars over abdomen below vertebral column, separated by white areas. Posterior half of body with four dark brown bars below vertebral column, each separated by white: first at front of anal fin; second over anal fin, bifurcating into two bars, one extending to center of anal fin, second to end of anal fin, resulting in three dark brown marks over anal fin; third bar at front of caudal peduncle, also bifurcating ventrally; fourth bar single on caudal peduncle. Two small spots at caudal-fin base, one dorsal and one ventral. Area on upper half of body with light brown scale margins. Three white areas extending up from vertebral column to fin bases: first at front of first dorsal fin; second at center of first dorsal fin; third at front of second dorsal fin. Nape with four dark brown bars crossing top, each separated by white spot. White bars extending down from vertebral column in front and behind pectoral-fin base. Pectoral-fin base with two brown spots, one dorsal and one ventral, top one with brown line behind it. Pupil of eye black with greenish highlights, surrounded by yellow ring. Eight dorsal brown bars extending out from pupil like spokes onto white iris. Three brown bars extending down from eye: first at 8 o’clock, extending forward over jaws; second at 6 o’clock, extending down behind jaws to under head; third at 4 o’clock extending short distance onto cheek. Short brown line from front of eye onto snout. Brown blotch behind upper part of eye extending towards nape. Three vertical brown bars along edge of preoperculum, lower bar extending under head, upper smallest. Another brown blotch between those on preoperculum and longest line under eye. First dorsal fin mottled light and dark brown with distinctive white sections: first spine with four white sections separated by orange brown on lower half and dark brown distally; white bar crossing from second white body bar up to just above center of first spine; lower half of fin orange brown, upper half dark brown. Second dorsal fin orange brown on basal half, upper half dark brown, crossed by four rows of white spots. Anal fin with three dark brown areas extending down from dark body bars, crossed by two rows of white spots on posterior half. Caudal-fin rays orange brown with small white spots on basal half, ventral edge of fin margined with white. Pectoral and pelvic fins immaculate.

Distribution. Known from the islands in the Sulu Sea, south to Java and west to Damar.

Etymology. The specific epithet is from the Greek word asymbasia meaning inconsistency, in reference to the variability of the presence of the preopercular pores.

Comparisons. Because some of the specimens lack only the IT pore, E. asymbasia must be compared not only with those lacking both the IT and POP but also with those lacking only the IT pore. Of the 35 species of Eviota with cephalic sensory-pore system pattern 2 (lacking only the IT pore cephalic), only eight others have branched pectoral-fin rays and a dorsal/anal formula of 8/8: E. bipunctata n. sp. (this paper), E. dorsimaculata , E. indica , E. lacrimosa , E. latifasciata , E. piperata , E. rubra , and E. shibakawai . Eviota asymbasia differs from E. lacrimosa by having the first dorsal fin of the male filamentous in some specimens, with 3 small discrete dark spots on lower portion of spine (absent in E. lacrimosa ) and no dark bars across nape (vs. present). It differs from E. bipunctata n. sp. by having distinct lines radiating down from under eye (vs. absent), and a sometimes filamentous first dorsal fin (not elongate in E. bipunctata n. sp.). Eviota dorsimaculata , E.indica , E. latifasciata , and E. shibukawai have a distinct dark spot over the preural centrum (absent is E. asymbasia ). Eviota ru bra has fimbriate urogenital papilla in both the male and female (non fimbriate in E. asymbasia ). The following species also lack the spots on the pectoral-fin base present in E. asymbasia : Eviota dorsimaculata , E. indica , E. latifasciata , E. shibukawai , and E. rubra . Eviota asymbasia is most similar to E. piperata in general coloration and in sharing POP variation, but differs in the number of postanal spots and modal number of pectoral-fin rays. Eviota asymbasia has six postanal spots, whereas E. piperata only has five ( Fig. 5 ). Greenfield & Winterbottom (2014) reported 16 [11] or 17 [12] pectoral-fin rays for E. piperata , whereas the counts for E. asymbasia are 13 [1], 14 [2], 15 [16], 16 [1].

Five described species also lack both the IT and POP pores: E. lacrimae , E. ocellifer , E. pinocchioi , and E. susanae . Eviota lacrimae has unbranched pectoral-fin rays (branched in E. asymbasia ), E. ocellifer has a distinctive black spot on the anteroventral portion of the first dorsal fin (vs. absent), E. pinocchioi has very long anterior naris tubes (vs. short), and E. susanae has fimbriate urogenital papilla in both males and females (vs. nonfimbriate).

Remarks. Greenfield & Winterbottom (2014) described E. piperata based on specimens from Palau. In that paper they said they were aware of an undescribed species of Eviota in Indonesia that was similar in coloration to E. piperata . In further examination of the specimens from Indonesia, we discovered that besides the undescribed species (here described as E. asymbasia ), E. piperata also occurred in the area. Eviota asymbasia occurs in the Philippine Is. from the islands in the Sulu Sea, south to Java and west to Damar Fig. 6 ). Eviota piperata occurs from Palau south to Raja Ampat and the Moluccas in Indonesia and Papua New Guinea, and then from Taiwan south in the South China Sea to the Philippine Islands at Apo Reef, Mindoro Provence, outside of the Sulu Sea.

Figures

FIGURE 2. Cephalic sensory-pores of Eviota asymbasia holotype, USNM 229476. Photograph by D. W. Greenfield.

FIGURE 3. Eviota asymbasia holotype, USNM 229476. Photograph by D. W. Greenfield.

FIGURE 4. Eviota asymbasia, CAS 238223, Damar, fresh specimen. Photograph by M. V. Erdmann.

FIGURE 5. Postanal spots of A. Eviota asymbasia - USNM 229476 - 14.0 mm, B. E. piperata - USNM 229481 - 17.4 mm. Photograph by D. W. Greenfield.

FIGURE 6. Distribution of Eviota asymbasia (yellow) and E. piperata (red).