Eviota kermadecensis, Hoese, Douglass F. & Stewart, Andrew L., 2012

Hoese, Douglass F. & Stewart, Andrew L., 2012, A new species of the gobiid genus Eviota (Teleostei: Gobioidei) from the Kermadec Islands, New Zealand, Zootaxa 3418, pp. 61-67 : 62-66

Eviota kermadecensis n.sp.

Figs. 1–4

Eviota sp. Francis et al., 1987: 8 (Kermadec Islands); Paulin et al., 1989: 225, 264, fig. 157.2b, key and listed; Francis, 1993: 41, 54, (Kermadec Islands).

Material examined: (n = 115, 11 lots)

Holotype: NMNZ P. 041191, 23.1 mm SL, male, Denham Bay, western side of Raoul Island., Kermadec Islands, New Zealand. 29o10’S, 177o57.3’W, rotenone, 9–11 m depth, A.L. Stewart, 0 9 Nov., 2004.

Paratypes: Raoul Island area: AMS I.45746-001 (formerly NMNZ P.028584), 5(12–19 mm SL), Denham Bay, 29o16’S, 177o 57’W, rotenone, 12 m. M.P. Francis & C. Ward, 0 4 Jun., 1992; AMS I.45779-010, 12 (14-19), North Meyer Island, rotenone, 15.5 m, M. Francis, 13 May 2011; AMS I.45807-019, 7(9-19), Herald Islands, 29o 15.1’S, 1–12 m, A. Balance, 16 May 2911; NMNZ P.017758, 3(22–24 mm SL), Meyer Islet, 29o14.55’S, 177o52.75’W, rotenone, 3 m, M.P. Francis and K. Bailey, 18 Aug., 1985; NMNZ P. 041075, 23(14–19.5 mm SL), southern end of Denham Bay, 29o16.6’S, 177o57.2’W, rotenone, 7–10 m A.L. Stewart, 0 5 Nov., 2004; NMNZ P. 041042, 40(14–21 mm SL); NMNZ P. 041090, 3(15–19 mm SL) ~ 500 m from Smith's Bluff, Denham Bay, rotenone, 14–16 m, A.L. Stewart, B. Stevenson, L. Chadderton & C. Duffy, 10 Nov., 2004; NMNZ P. 041096, 14(12–19 mm SL) taken with holotype; NMNZ P. 041134, 14(15–24 mm SL); NE corner, Meyer Islet, 29o15’S, 177o52’W, rotenone, 10–12 m, A.L. Stewart, 0 8 Nov., 2004; NMNZ P. 041151, 10(14.2–21.3 mm SL); Denham Bay, 29o17.2’S, 177o57.3’W, rotenone, 9–10 m, A.L. Stewart, 0 5 Nov., 2004; NMNZ P. 041161, 1(16 mm SL), approx. 400 m from the southern end of Denham Bay beach, 29o16.45’S, 177o57.05’W, rotenone, 0–3 m, A.L. Stewart 0 9 Nov., 2004. Stawell Shoal: AMS I.45860-006, 1(20), north of Stella Passage, 30o31.7’S, 178o33.6’W, A. Balance, 25 May 2011.

Non-type material: AMS I.45771-005, 1(18), west side of Meyer Island, 29o14.8’S, 177o52.9’W, 20-22 m; AMS I.45773-004, north side of Meyer Island, 29o14.58’S, 177o52.72’W, 14-16 m; AMS I.45778-001, south-west side of Napier Island, 29°13.98’S, 177°57.57’W; AMS I.45787-015, 5(13-20), 29°18.53’S, 177°53.75’W, 7-11 m; AMS I.45794-008, 1(18), Raoul Island, Boat Cove, 29°16.78’S, 177°53.82’W; AMS I.45840-017, 7(14-20), west side of Macauley Island, 30o13.7’S, 178o26.72’W, 21-24 m; AMS I.45815-006, 4(13-22), south-west side of Nugent Island, 29o13.9’S, 177o52.22’W, 12-16 m; AMS I.45826-014, 2(16-18), North Meyer Island, 29o14.48’S, 177o52.72’W, 16-18 m; I.45827-020, 2(15-17), north west corner of North Meyer Island, 29°14.48'S, 177°52.72'W; NMNZ P.013500, 1(17 mm SL), close to east side of Meyer Islet, off Raoul Island, 29o14.83’S, 177o51.93’W, pipe dredge, 25–29 m, R/V Acheron, Stn. B.S. 574, 11 Sep., 1976.

Diagnosis. The following combination of characters distinguishes E. kermadecensis from congeners: dorsalfin rays usually VI + I,10; anal-fin rays usually I,8; most pectoral-fin rays branched; cephalic sensory-pore system pattern 1 (terminal lateral canal pore present); males with first dorsal spine filamentous, base of pectoral fin with two prominent spots (darker than body color or much lighter than body color), lower spot usually smaller than upper and sometimes obscure; four segmented pelvic-fin rays plus a rudimentary fifth ray present, pelvic rays partly separated, connected about one-third to one half between segmented rays 2–4 and almost completely connected to tip between spine and first ray; rudimentary fifth pelvic ray bound in membrane to fourth ray; subcutaneous bars on lower trunk behind anus usually lacking in preserved adults; nasal tubes short, tips of tubes with thin black ring, dorsal, anal and caudal fins usually grey to black; dorsal fin with some light spots. Vertebrae usually 26.

Description (holotype counts underlined). Dorsal-fin rays: VI + I,9(7), VI + I,10(37); anal-fin rays I,8(41), I,9(2); pectoral-fin rays 16(6), 17(22), 18(12); pectoral-fin ray number4 (from top of fin) through lowermost may be branched, 8 through lowermost ray always branched; pelvic-fin rays I,4 plus rudiment; terminal tips on fourth segmented pelvic-fin ray 6–10 in specimens less than 21 mm SL, averaging 7.7 (n = 21), mode 8, and 9–10 in specimens 21–24 mm SL, averaging 9.7 (n = 7), mode 10; segments between consecutive branches of fourth segmented pelvic-fin ray 1–3, 2 in over 99% of interspaces, rarely 1 or 3; pelvic-fin membrane reduced; branched caudal-fin rays 11(5), 12(17), 13(10), 14(1); segmented caudal-fin rays 17(33), 18(1); longitudinal scale count 21(1), 22(3), 22(9), 23(12), 24(2); transverse scale count (TRDB) 7(14), 8(12); breast scaleless; vertebrae 10(35) precaudal plus 16(35) caudal, total 26. First two dorsal-fin spines in males usually filamentous, often only first in specimens below 18 mm SL, first longest; maximum extension to just behind end of second dorsal-fin base; females sometimes with first spine filamentous. Pelvic fin usually reaches to urogenital papilla, maximum length to just beyond anal-fin origin. Cephalic sensory-pore system pattern 1; superficial neuromast (cutaneous papillae) system pattern A. Male genital papilla the non-fimbriate pattern of Lachner & Karnella (1980); papilla elongate with small lobes at posterior rim and a median enlarged lobe. Anterior nostril midway between upper lip and eye at end of short tube; posterior nostril in contact with orbit.

Head pores: (terminology follows Lachner & Karnella (1978), where different their term given in parentheses): posterior nasal pore (nasal) immediately median to the posterior nostril; median anterior interobital pore above middle of eye, median posterior interorbital pore above posterior end of eye, postorbital pore (supraotic) behind eye in line with upper margin of eye, infraorbital pore (anterior otic) just behind middle of eye and terminal lateral canal pore (intertemporal) on each side of head just before posterior preopercular margin; two preopercular pores.

Midline of belly usually naked only in narrow medial area, sometimes with a few scales crossing midline before anus. Scales reach forward to just short of pectoral fin base, with a broad naked area above a line from upper pectoral base to just behind second dorsal origin.

Pelvic rays laterally branched with each branch not subdividing ( Fig. 2 ).

Coloration in preservative: Head dorsally with scattered brown speckles, spots often arranged in circles forming ocellated spots; females generally paler having fewer spots; head laterally with scattered brown speckles, often forming ocellated spots as on top of head; head with little or no pigment ventrally, except for a small patch of melanophores anteriorly on chin in some specimens; upper lip with moderately dense concentration of melanophores on anterior quarter to half of lip; lower lip with concentration of melanophores only at distal tip; sometimes with small flecks of grey posteriorly; nasal tubes with thin black distal rim, faint in small specimens; pectoral-fin base usually with an upper pale spot and a lower pale spot, separated medially by a concentration of melanophores, usually with a thin line of melanophores around whole spot; light spots often with scattered melanophores, but spots usually distinctly lighter than bar separating spots; in some specimens the melanophore concentration is highest in the spots, with the spots appearing dark gray and darker than space between them; lower spot usually smaller than upper spot and sometimes obscure (as in holotype); dorsal trunk midline usually with melanophores forming faint vertical bands, extending only a short distinct ventrally; first band at origin of first dorsal fin, second below first dorsal fin, third below space between dorsal fins, fourth under second dorsal origin, fifth and sixth below second dorsal fin, seventh just behind end of second dorsal fin, eighth and sometime a ninth on caudal peduncle; posterior bands fainter; in most specimens the bands have irregular margins, with the margins darker than central area; frequently (particularly in young only the dark margins are visible; in juveniles below 16 mm SL) bands are indistinct; trunk with dark crescent-shaped marks at scale pockets, most distinct dorsally, usually with only scattered melanophores ventrally; belly with scattered subcutaneous melanophores, not forming distinct pattern, midline of belly and sometimes lower sides with dense concentration of melanophores; subcutaneous bars and spots usually not discernible on lower trunk behind anus; in specimens below 16 mm SL, sometimes with 3 spots along base of anal fin and 3 on caudal peduncle, often with faint traces of subcutaneous bands extending dorsally, rarely with distinct subcutaneous bands; first dorsal fin grey to black, usually with small white or clear spots, often with pale areas ventrally; in females pigment may be confined to thin line near distal margin of fin; second dorsal fin pale to black, with light spots forming 4–5 rows on lower two-thirds of fin; females often with little pigment; anal fin pale to black, with melanophores concentrated on membranes between rays, giving fin a striped appearance; pigment concentrated on anal fin distally in juveniles and females below 18 mm SL; caudal fin clear in young to grey in adults, with clear spots forming wavy bands; pectoral and pelvic fins clear, without melanophores.

Coloration in freshly collected specimens ( Fig. 4 ): Head and body translucent green, with a dense concentration of melanophores over whole region; head with scattered dusky orange spots subequal to pupil diameter; ventrally on head 3 large orange spots below preoperculum and one just behind end of jaws; scales on dorsal part of body with dark edges posteriorly forming short vertical marks; black subcutaneous bars extending upward from anal fin to near dorsal fin; first just behind anal origin, followed by two above anal fin, followed by three vertical bars on caudal peduncle; a dark vertical black bar at end of caudal peduncle; pectoral fin base with a round black spot dorsally larger than pupil diameter and ventrally a smaller spot, subequal to pupil diameter; dorsal fins with black and orange; caudal fin largely orange becoming blackish ventrally; anal fin black.

Etymology. The specific epithet, kermadecensis is from the type and only known locality, the Kermadec Islands of New Zealand.

Remarks. Eviota kermadecensis shows considerable sexual dimorphism. Males average a larger size than for females (mean = 19.3 mm SL for males and 15.9 mm SL for females, with 80% of the females between 14 and 17 mm SL versus 60% of males between 18 and 21 mm SL ( Fig. 3)). Males are less numerous, with females being 1.5 more abundant than males. Taru & Sunobe (2000) noted an average F:M ratio of 1.4 for the related species, Eviota abax . Males typically have the first two dorsal spines filamentous, but females usually have only the anterior spine slightly prolonged. Males are generally more heavily pigmented. The colour and filamentous spine differences may relate primarily to the larger size of males.

Distribution. Eviota kermadecensis is known only from the Kermadec Islands including Raoul Island, area, Macauley Island and Stawell Shoal. It has been collected from rocky reefs at depths ranging from 0 to 29 m.

Comparisons. Eviota kermadecensis is a member of Species Group I of Lachner & Karnella’s (1980) and Jewett & Lachner (1983), which is diagnosed by the following: cephalic sensory-pore system pattern 1 (NA, AITO, PITO, SOT, AOT, IT and POP pores present); vertebrae usually 26; some pectoral-fin rays branched; urogenital papilla of male nonfrimbriate; and fifth segmented pelvic-fin ray absent or very short. The vertebral counts and branching of pectoral rays are also characteristic of Group II, with both groups typically spending most of their time on the bottom, while members of Group III generally are more free-swimming species, with 25 vertebrae and unbranched pectoral rays.

The present species belongs to a subgroup, which has the pelvic-fin membranes joining first four segmented rays reduced, connecting less than half of the basal portion of the rays. Species in Group I ( Lachner & Karnella, 1980; Karnella & Lachner, 1981, Jewett & Lachner, 1983) include: E. abax ( Jordan and Snyder, 1901); E. albolineata Jewett & Lachner, 1983 ; E. distigma Jordan & Seale, 1906; E. disrupta Karnella & Lachner, 1981 ; E. epiphanes Jenkins, 1903 ; E. fasciola Karnella & Lachner, 1981 ; E. guttata Lachner & Karnella, 1978 ; E. herrei Jordan & Seale, 1906; E. inutilis Whitley, 1943 ; E. irrasa Karnella & Lachner, 1981 ; E. japonica Jewett & Lachner, 1983 ; E. korechika Shibukawa & Suzuki, 2005 ; E. latifasciata Jewett & Lachner, 1983 ; E. masudai Matsuura & Senou, 2006 ; E. melasma Lachner & Karnella, 1980 ; E. monostigma Fourmanoir, 1971 ; E.nebulosa Smith, 1958 ; E. nigripinna Lachner and Karnella, 1980 ; E. pardalota Lachner & Karnella, 1978 ; E. pseudostigma Lachner & Karnella, 1980 ; E. punctulata Jewett & Lachner, 1983 , Eviota randalli Greenfield, 2009 ; Eviota readerae Gill & Jewett, 2004 ; Eviota rubriguttata Greenfield & Suzuki, 2011 ; E. rubrisparsa Greenfield & Randall, 2010 ; E. smaragdus Jordan & Seale, 1906; E, toshiyuki Greenfield & Randall, 2010; and E. winterbottomi Greenfield & Randall, 2010 . Eviota kermadecensis is most similar to members of the Eviota ephiphanes subgroup, which normally have vertical trunk bars. In preserved material of E. kermadecensis the bars are confined to the dorsal surface and do not extend below the midside. The E. ephiphanes group is confined to the western and central Pacific. Eviota kermadecensis differs from most of these species in having the second dorsal usually I, 10. The only other species in the group with the same count are Eviota abax and E. masudai from Japan. Those species lack transverse trunk bars and have a large dark spot on the nape above the operculum.

Figures

FIGURE 1. Holotype of Eviota kermadecensis NMNZ P. 41191, 23.1 mm SL male.

FIGURE 2. Ventral view of left pelvic fin of Eviota kermadecensis, composite based on several specimens.

FIGURE 4. Freshly collected specimen from 2004 of Eviota kermadecensis, photo A. Stewart.