Eviota piperata, Greenfield, David W. & Winterbottom, Richard, 2014

Greenfield, David W. & Winterbottom, Richard, 2014, Eviota piperata, a new gobiid species from Palau (Teleostei: Gobiidae), Zootaxa 3755 (3), pp. 295-300 : 296-299

Eviota piperata n. sp.

Peppered Dwarfgoby (Figs. 1–3)

Holotype. ROM 84490, 20.1 male, Palau, Sonsoral State, about middle of E coast of Fana Island, 05°21’17”N, 132°13’27”E, reef slope (30–44°) of coral rock with some rubble and coarse sand patches, moderate amounts of hard coral ( Acropora, Pocillopora, Millepora ), many dark colored sponges, 6–9 m, rotenone, field number RW08- 0 6, Winterbottom, R., Westneat, M., Williams, J., Holleman, W., Hubley, B., Winterbottom, M., McCord, C., Rall, H., 12 September 2008.

Paratypes: ROM 94753 (ex-ROM 84490), 7 males, 17.4–20.1, 18 females, 8.1–18.8, taken with holotype, photographed specimen in vial; AMS I.146290-001, 18.2 male, 18.8 female, taken with holotype; CAS 236164, 20.5 male, 18.5 female, taken with holotype; USNM 410661 18.3 male, 18.1 female, taken with holotype, ROM 94754 (ex-ROM 84501), 4 males, 15.5–19.6, 5 females 12.1–16.1.

Other material examined: ROM 84501 (123), 10.7–18.6 mm, single specimen in vial photographed. Palau, Sonsoral State, off SE tip of Pulo Anna, about 10 m from surf line, 04°39’09”N, 131°57’16”E, Halimeda , heavy cover of hard corals ( Acropora, Pocillopora, Millepora ), plate corals, lettuce corals, U-shaped channel about 10 m wide at seaward side and 3 m wide at shore side, floor 17 m at outside shelving to 9 m at tip, numerous caves at base of tip, floor mostly of live coral, 7–15 m, rotenone, field number RW 08-09, Winterbottom, R., Westneat, M., Williams, J., Holleman, W., Hubley, B., Winterbottom, M., McCord, C., 13 September 2008. ROM 76386 (9), 10.4–14.7 mm, single specimen in vial photographed, Palau, Ngatopang, W coast Babeldaob Island, lagoon close to outer barrier reef, 07°29’32.1”N, 134°25’28.6”E, bommies rising from sand/silt adjacent to coral rubble, brown algae, 0–7.3 m, rotenone, field number RW 04-23, Winterbottom, R., Holleman, W., Hubley, B., Winterbottom, D., 30 May 2004.

Diagnosis. The following combination of characters distinguish E. piperata from congeners: cephalic sensorypore system Group II (lacking only the IT pore), or lacking the IT and various combinations of the POP, from both absent to only the upper or lower pore absent; dorsal/anal–fin formula 8/8; some pectoral-fin rays branched; no dark spot over ural centrum; male genital papilla not fimbriate; cheek and body heavily peppered with chromatophores.

Description. Dorsal-fin rays VI+I,8 (all); anal-fin rays I,8 (all); pectoral-fin rays 17 (16[11], 17[12]), rays 7– 16 branched in holotype; fifth pelvic-fin ray 7.8% (7.2–16.1, 10.4%) of 4th ray; 6 relatively long branches on 4th ray (4[6], 5[3], 6[1]); 3 (2[6], 3[4]) segments between consecutive branches of 4th pelvic-fin ray; pelvic-fin membrane reduced, about ¼ the distance to the first branch; 12 (12[4], 13[4]) branched and 17 (all) segmented caudal-fin rays; 24 (24[3], 25[7]) lateral scale rows; transverse scale rows 6 (all); vertebrae 24; midline of abdomen with cycloid scales; first dorsal fin triangular in shape, first two spines of first dorsal fin may be filamentous in males as small as 12.5 mm, extending back past end of the second dorsal fin in holotype; genital papilla in male smooth, not fimbriate, fringed at 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 70° from the horizontal axis; mouth oblique, forming an angle of about 50° to horizontal axis of body, lower jaw not projecting; maxilla extending to posterior third of pupil; anterior tubular nares short, just reaching to edge of upper lip; gill opening extending forward to posteroventral edge of preoperculum; cephalic sensory-pore system pattern Group II (only IT pore missing), or lacking the IT and various combinations of the POP, from both absent to only the upper or lower pore absent.

Measurements (based on holotype and 11 paratypes, 12.1–20.1). Head length 31.4 (30.3–34.2, 32.2); origin of first dorsal fin 33.7 (33.7–37.9, 36.4), lying behind posterior margin of pectoral-fin base; origin of second dorsal fin 56.6 (54.9–60.3, 57.6), slightly in advance of anal-fin origin; origin of anal fin 60.5 (58.7–62.7, 60.3); caudalpeduncle length 22.7 (22.4–24.8, 23.9); caudal-peduncle of moderate depth 13.5 (10.9–15.3, 13.3); body relatively slender, its depth 21.4 (19.6–22.2, 21.1); eye diameter 8.7 (8.7–11.7, 11.1); snout length 5.1 (4.2–6.0, 5.1); pectoral-fin length 28.8 (25.5–37.5, 31.4); pelvic-fin length 55.3 (30.1–55.3, 36.6).

Color in preservative of holotype (Fig. 1). Background color of head and body pale yellowish. Head with a heavy peppering of chromatophores on the top and nape, on the cheeks, and on the operculum. A concentration of chromatophores along the posterior edge of the preoperculum that extends down to a heavy peppering of chromatophores on the branchiostegal membranes. A cluster of chromatophores below the eye extending down behind the jaws. Interorbital area, snout, nares and jaws with a lighter peppering. Pupil of the eye clear, iris black. A heavy band of chromatophores on the pectoral-fin base. Peppering of chromatophores less intense on the body than on the head, scale pockets outlined with chromatophores, more intense on the dorsal half of the body. Abdomen peppered. A thin dark line running along the middle of the sides of the body along the caudal peduncle. Five obvious, dark, postanal midline spots followed by a smaller spot, matched by a similar spot at the top of the caudal-fin base. Caudal, anal and second dorsal fins peppered with chromatophores and melanophores. Filamentous spine of first dorsal fin with a series of spaced brown spots. Remainder of fin peppered with small brown spots, its distal margin darker. Pectoral and pelvic fins lighter than other fins.

FIGURE 1. Eviota piperata , holotype preserved, ROM 84490. Photograph by D.W. Greenfield.

FIGURE 2. Eviota piperata , holotype fresh, ROM 84490. Photograph by R. Winterbottom.

FIGURE 3. Eviota piperata , paratype fresh, ROM 94753. Photograph by R. Winterbottom.

Color of fresh holotype (Fig.2). Background color of head and body light brown. Scale pocket margins outlined with chromatophores, more intense on dorsal surface. Head darker than body, heavily peppered with large chromatophores, more concentrated on preopercular margin, under eye, behind jaws, and under head. Two dark bars crossing top of head behind eyes. Nares dark with black tips. Pupil of eye black, iris yellow with orange spokes radiating out from pupil. Pectoral-fin base dark, slightly darker on top and bottom. Body with six subcutaneous bars: the first at anterior half of first dorsal fin; the second at posterior half of first dorsal fin; third from origin of second dorsal fin to anal-fin origin; fourth at end of anal fin; fifth and sixth on caudal peduncle. Five postanal midline spots on ventral surface of body: the first at anal-fin origin, second at end of anal fin; third, fourth, and fifth on caudal peduncle, followed by a smaller spot at ventral caudal-fin margin next to procurrent spines, this last spot matched at top of caudal fin. Caudal and anal fins brown, heavily peppered with melanophores. Filamentous spine of first dorsal fin with a series of spaced black spots with orange halos. Remainder of fin brown with an orange tinge, its distal margin darker. A narrow light area running from third black spot of first dorsal spine down across fin to base of fourth spine. A single black spot on membrane between spines five and six. Second dorsal fin brown, heavily peppered with chromatophores, lighter on distal half. Spine with four spaced black spots similar to those on the first spine of the first dorsal fin, similar dark spots on the soft rays. Pectoral and pelvic fins lighter than other fins.

Fresh color of paratype. In some specimens, the peppering of chromatophores on the head is lighter revealing the concentration of chromatophores on various portions of the head (Fig. 3).

Distribution. Only known from Palau. Eviota piperata was collected throughout the Palauan Islands, from the north tip of Babeldaop to Helen Reef, the southernmost of the South West Islands. It was locally abundant in the South West Islands (except at Helen Reef, where only two specimens were collected despite nearly two weeks of sampling), with a single collection from Pulo Anna containing 131 specimens, and a total of over 330 specimens collected in limited collecting effort (7 days). Two three-week long expeditions to the main Palauan Islands (in 2004 and 2006) resulted in the collection of only 34 specimens of this species. The five South West Islands (excluding Helen Reef) are all small coral limestone islands perched on submerged volcanic peaks, with small shallow lagoons and steep outer slopes to deepwater.

Etymology. The specific epithet is from the Latin piper (pepper) referring to the heavy peppering of melanophores over the head and rest of the body.

Comparisons. Of the 30 described species of Eviota in cephalic sensory-pore system Group II (lacking only the IT pore) (Table 1), only four others have branched pectoral-fin rays and a dorsal/anal-fin formula of 8/8 ( E. dorsimaculata , E. indica , E. latifasciata , and E. rubra ). Eviota dorsimaculata , E. indica and E. latifasciata all have a dark spot on the caudal peduncle over the ural centrum that is lacking in E. piperata , and neither E. indica nor E. latifasciata have an elongation of the first dorsal fin, which rarely is slightly elongated in E. dorsimaculata (the first spines in males of E. piperata may be filamentous). Eviota rubra also has branched pectoral-fin rays and no spot over the ural centrum; however, E. rubra has a distinctive fimbriate genital papilla in both the male and female, whereas the papillae are non fimbriate in E. piperata . Eviota rubra also lacks the heavy peppering of melanophores present in E. piperata as well as other color differences ( Greenfield & Randall, 1999, 2004 -Fig. 62).

TABLE 1. Species of Eviota included in the cephalic sensory-canal pore system Group II (IT missing), dorsal/anal-fin formulas (D/A) and pectoral-fin branching (S=simple, BR=branched).

ΡeʗtoɼDǀ bɼDnʗh!ng D/Α 8/7 D/Α 8/8 D/Α 9/7 D/Α 9/8 D/Α 10/9 E. anʗora s x

E. atrivantris s x

E. nigrispina s x

E. prasitas s x

E. rubriʗaps s x

E. springari s x

E. storthynx s x

E. spi/ota s x

E. ʗomata s x x

E. sigi//ata s x

E. zabrina s x x

E. pa//uʗida ΒR x

E. dorsimaʗu/ata ΒR x

E. indiʗa ΒR x

E. /aʗrimosa ΒR x

E. /atiʃasʗiata ΒR x

E. piparata n. sp ΒR x

E. rubra ΒR x

E. aʃa/ai ΒR x

E. bimaʗu/ata ΒR x

E. hinanoaa ΒR x

E. hoasai ΒR x

E. japoniʗa ΒR x

E. prasina ΒR x

E. punʗtu/ata ΒR x

E. quaans/andiʗa ΒR x

E. saipanansis ΒR x

E. zonura ΒR x

E. tigrina ΒR x E. vario/a ΒR x Because the number of preopercular pores (POP) can be variable in E. piperata it also is necessary to compare it to five other species of Eviota that lack both the IT and POP: E. lacrimae , E. ocellifer , E. pinocchioi , E. sparsa and E. susanae . All of these species except E. susanae have a dorsal/anal-fin formula of 9/8, (8/ 8 in E. piperata ). Eviota susanae has a fimbriate genital papilla in both the male and female (non-flimbrate in E. piperata ); the 5th pelvic-fin ray is 53–90% of the length of the 4th ray in E. sparsa (vs. 7.2–16.1% in E. piperata ); E. ocellifer has the anteroventral region of the first dorsal fin black, bordered above with pale yellow, whereas E. piperata lacks that dorsal fin coloration; the anterior tubular nares are black and very elongate, reaching well anterior to the upper lip in E. pinocchioi (nares only reach to the upper lip in E. piperata ).

Remarks. Eviota piperata is unusual in exhibiting variation in the presence of the preopercular pores (POP). Even though the cephalic-sensory pore system groupings do not appear to reflect genetic relationships ( Tornabene et al. 2013), they are useful in differentiating different species and species groups and usually do not vary within a species. We are aware of an undescribed species of Eviota in Indonesia that is similar in coloration to E. piperata but differs in pore patterns. The relationship between these two species awaits the collection of more material, especially DNA tissue. We note in passing that 1 of 234 specimens that we assigned to E. piperata possessed the IT pore – we regard this specimen as an anomaly.