Eviota readerae, Gill & Jewett, 2004

Gill, Anthony C. & Jewett, Susan L., 2004, Eviota hoesei and E. readerae, New Species of Fish from the Southwest Pacific, With Comments on the Identity of E. corneliae Fricke (Perciformes: Gobiidae), Records of the Australian Museum 56 (2), pp. 235-240 : 238-240

Eviota readerae n.sp.

Figs. 3, 4

Eviota n.sp. B.—Gill & Reader, 1992: 222 (Elizabeth and Middleton Reefs).

Type material. HOLOTYPE: AMS I.27141-018, 17.9 mm SL, Middleton Reef, tidal pools on exposed reef flat near wreck of Fuku Maru, 29°28.8'S 159°07.5'E, rotenone, A.C. Gill & S.E. Reader, 7 December 1987. PARATYPES: AMS I.27134-038, 3: 7.8–15.3 mm SL, Middleton Reef , 29°27.2'S 159°06.8'E, north face of outer reef slope, coral bommie, 6–9 m, rotenone, A.C. Gill et al., 4 December 1987 ; AMS I.27138-056, 3: 14.4–15.9 mm SL, Middleton Reef , mid back lagoon, 29°27.8'S 159°05'E, patch reef, 4– 9 m, rotenone, A.C. Gill et al., 5 December 1987 ; AMS I.27148-031, 4: 9.6–17.5 mm SL, Elizabeth Reef , outer east slope, 29°57.2'S 159°01.2'E, 10 m, rotenone, A.C. Gill et al., 10 December 1987 ; AMS I.27149-034, 1: 14.5 mm SL, Elizabeth Reef , northeast outer slope, 29°54.8'S 159°02.8'E, 8–10 m, rotenone, A.C. Gill et al., 10 December 1987 ; AMS I.27149-040, 3: 9.5–15.9 mm SL, collected with AMS I.27149-034; AMS I.27296-001, 1: 10.5 mm SL, Middleton Reef , outer reef edge near wreck of Runic, 29°27.4'S 159°03.7'E, 30–40 m, airlift substrate sampler, J.K. Lowry & R. T. Springthorpe, 5 December 1987 ; BMNH 2003.1.22.7–8, 2: 9.9–14.9 mm SL, collected with AMS I.27134-038; USNM 372388 , 2 : 14.0– 14.6 mm SL, collected with AMS I.27134-038 .

Diagnosis. The following combination of characters distinguishes Eviota readerae from congeners: dorsal-fin rays VI + I,9; anal-fin rays I,8; at least some pectoral-fin rays branched; fifth segmented pelvic-fin ray lacking; cephalic sensory-pore system pattern 1; male genital papilla nonfimbriate; 12–13 dark b ars or saddles on trunk from origin of spinous dorsal fin to mid peduncular spot, not extending below midline (except in small juveniles); and pectoral-fin base with prominent circular dark spot dorsally (only occasionally with additional small diffuse spot ventrally).

Description. Dorsal-fin rays VI + I,9(20); anal-fin rays I,8(20); pectoral-fin rays 16(1), 17(16), 18(3); pectoral-fin rays 9 through 17 may be branched, 11 through 15 always branched; pelvic-fin rays I,4 (20); branches on fourth segmented pelvic-fin ray 7–12, averaging 8.9; segments between consecutive branches of fourth segmented pelvicfin ray 0–3, averaging 1.1; pelvic-fin membrane reduced; branched caudal-fin rays 13(6), 14(4), 15(1); segmented caudal-fin rays 17(20); lateral scale rows 23(1), 24(2), 25(5), 26(3); transverse scale rows 6(4), 7(8); breast scaleless; vertebrae 10(16) precaudal plus 16(16) caudal, total 26.

Spinous dorsal fin not elongate in either sex. Pelvic fin usually reaches to anus, maximum length to about base of second segmented anal-fin ray. Cephalic sensory-pore system pattern 1; superficial neuromast (cutaneous papillae) system pattern A. Male genital papilla non-fimbriate.

Preserved coloration. Four weak saddles to dark bars present dorsally on head and on nape in front of spinous dorsal fin; anteriormost two bars ending ventrally in prominent dark spots; head otherwise generally pale or with clusters of brown chromatophores, usually around posterior margin of eye, on lower cheek, just behind mid-posterior edge of eye, on anterior part of opercle, on subopercle, on branchiostegal membrane (adjacent to subopercle cluster), and sometimes on chin and lower lip; pectoral-fin base with prominent circular dark spot dorsally, which may encroach posteriorly on to bases of upper few pectoral-fin rays; small diffuse second spot or cluster of melanophores occasionally on ventral part of pectoral-fin base; 12–13 prominent dark bars present on trunk from origin of spinous dorsal fin to midpeduncular spot; bars generally not extending below midline, often reduced to series of short dorsal saddles, extending below midline only in small juveniles; five subcutaneous spots or short bars on lower postanal trunk, though some or all may be weakly developed or lacking in some specimens; last subcutaneous bar continuous with prominent caudal peduncle spot, which is all or mostly developed kidney-shaped or semicircular mark over entire subcutaneous; scale margins may be lightly edged with base in E. fasciola , a dorsal and a ventral well-developed melanophores, but scale pockets not outlined; trunk bars discrete circular spot in E. disrupta , and a dorsal and a and subcutaneous spots sometimes extending slightly on to ventral well-developed indiscrete oval or circular spot in E. dorsal and anal fins; spinous dorsal fin immaculate pale, or irrasa ); pectoral spot equal to or darker than other body pale with 1–2 broad, diffuse dusky bars; second-dorsal and pigmentation (versus equal to or less than in E. epiphanes , anal fins varying from pale to dusky; caudal, pectoral and equal to in E. irrasa , and darker than in E. fasciola and E. pelvic fins may have rays bordered with melanophores, but disrupta ); trunk bars not extending below midline (reduced otherwise pale. to saddles in E. epiphanes , and extending to lower body in

E. fasciola and E. disrupta ); trunk bars usually discrete and Live coloration. Not recorded. uniform (versus interrupted anteriorly in E. disrupta , and not discrete in E. irrasa ); branchiostegal mark present Etymology. The specific epithet is for Sally E. Reader, who

(versus absent in E. epiphanes ); no scale pocket pigmentassisted the first author with the collection of most of the

ation (versus weakly developed in E. irrasa , and well type specimens, and kindly arranged the loan of specimens

developed in E. epiphanes ); and pale area present on for this study.

posterior opercle and anterior pectoral-fin base (absent in Comparisons. Eviota readerae is a member of Lachner & E. epiphanes ). Karnella’s (1980) Group I species-group, which is Remarks. Eviota readerae is known only from Middleton diagnosed by the following: total vertebrae usually 26; some and Elizabeth Reefs on the Lord Howe Rise, Tasman Sea. It pectoral-fin rays branched; male genital papilla non- has been collected from tidal pools, lagoon patch reefs and fimbriate; and cephalic sensory-pore system 1 (NA, AITO, reef slopes at depths ranging from about 0.3 to at least 30 m. PITO, SOT, AOT, POP and IT pores present). It belongs to a complex of species within this group that Karnella & Identity of Eviota corneliae Fricke, 1998 Lachner (1981) termed the Eviota epiphanes complex. Eviota readerae and the other members of this complex (E. Fricke (1998) described E. corneliae on the basis of two disrupta Karnella & Lachner, 1981 , E. epiphanes Jenkins , specimens from Maré Island, Loyalty Islands. He assigned 1903, E. fasciola Karnella & Lachner, 1981 , and E. irrasa the species to the E. epiphanes complex on the basis of it Karnella & Lachner, 1981) differ from other Group I species having vertical trunk bars. Several salient details are missing in sharing the following combination of characters: dorsal- from Fricke’s description, particularly details of head pore fin rays usually VI + I,9; anal-fin rays usually I,8; no structure. We therefore borrowed the holotype (SMNS elongation of spinous dorsal-fin rays in either sex; pelvic- 19870) in order to make comparisons with E. readerae and fin rays I,4; pelvic-fin membranes joining segmented rays other E. epiphanes complex species. Our examination of reduced; segments between consecutive branches of fourth the holotype revealed that it is not a species of Eviota , pelvic-fin ray usually 1; and five subcutaneous spots on differing in various details: head pores absent (versus usually lower postanal trunk. The species are also similar in general present in Eviota ; absent only in one undescribed species); coloration: head and nape with bars dorsally; at least short subcutaneous spots or bars absent (versus almost always bars or saddles along the dorsal midline of the trunk; head present); and gill opening wide (versus narrow), extending with scattered large chromatophores ventrally and laterally, often arranged in clusters or large spots; caudal peduncle with well-developed subcutaneous spot, which is integrated with a weak to strong subcutaneous bar; and first dorsal fin with dark irregularly mottled or barred pattern. The five species are differentiated on the basis of coloration characters (see Karnella & Lachner, 1981: table 1). The following characters distinguish E. readerae : pectoral-fin base with prominent circular dark spot dorsally (versus Fig. 5. Trimmatom eviotops, SMNS 19870, 14.0 mm SL, holotype of Eviota weak spot dorsally in E. epiphanes , well- corneliae Fricke, Maré Island, Loyalty Islands. (Photographed by H. Taylor.)

to vertical through rear edge of eye. We also noticed several discrepancies with the original description: there are I,5 not I,4 pelvic-fin rays (the inner ray is small and unbranched); whereas Fricke recorded the lower seven pectoral-fin rays as branched, we could find no evidence of branched rays in the fin (although the ray tips of most rays are broken, some of the lower rays are undamaged and not branched); Fricke recorded a spine and eight rays in the anal fin, but there are 10 rays, the anteriormost of which is bilaterally paired, thus not a true spine; and the positions of some of the trunk bars are incorrectly depicted (compare Fricke’s fig. 1 with Fig.

5). Also, although Fricke correctly gave the length of the holotype as 14.0 mm SL, the scale bar in his figure suggests that the specimen is about 35 mm SL; the scale bar is obviously intended to indicate 2 mm, not 5 mm as incorrectly indicated in the figure caption.

The E. corneliae holotype keys to Trimmatom Winterbottom & Emery (1981) using Larson & Murdy’s (2001) key to western central Pacific gobiid genera. We therefore contacted R. Winterbottom, current expert on Trimmatom and related genera, for assistance. He confirmed the generic assignment, although noting that the recognition of the genus as distinct from Trimma Jordan & Seale is tentative; his phylogenetic studies suggest that Trimmatom is nested within Trimma , and that the recognition of Trimmatom may therefore render Trimma paraphyletic (see also Winterbottom, 1990). He further identified the holotype as Trimmatom eviotops ( Schultz, 1943) . Eviota corneliae Fricke (1998) is therefore a junior subjective synonym of Trimma eviotops Schultz (1943) .

ACKNOWLEDGMENTS. We are grateful to the following for the loan of specimens: R. Fricke, D.F. Hoese, H.K. Larson, M. McGrouther, J.E. Randall, S.E. Reader and A. Suzumoto. Specimens of the new species were collected by the first author and associates on an Australian Museum expedition to Middleton and Elizabeth Reefs in 1987; he extends his thanks to other expedition participants, particularly S.E. Reader, M. Cordell and D. Leadbitter for their assistance in making rotenone stations. We are grateful to D.F. Hoese and R. Winterbottom for helpful discussions, in particular to R. Winterbottom for his input on the identity of E. corneliae and for review of the manuscript. We thank O.A. Crimmen for radiographs, H. Taylor for the photographs of E. readerae and the holotype of E. corneliae , and J.R. Schroeder for his drawing of the holotype of E. hoesei . The second author thanks the late Ernest A. Lachner who, in about 1971, lured her into the study of Eviota with the promise that it was a tidy little group comprising just a few undescribed species, for his inspiration and collaboration on earlier papers.