Trimma tevegae Cohen & Davis, 1969

Winterbottom, Richard & Hoese, Douglass F., 2015, A revision of the Australian species of Trimma (Actinopterygii, Gobiidae), with descriptions of six new species and redescriptions of twenty-three valid species, Zootaxa 3934 (1), pp. 1-102 : 87-90

Trimma tevegae Cohen & Davis, 1969

Bluestripe Pygmygoby

Figs. 49–50 , Pl. 4 A

Trimma tevegae Cohen & Davis, 1969:321 (Rabaul, New Britain); Kuiter, 1992:236 D; Shao et al., 1992:330, B; Kobayashi, 1994:120 (# 4); Randall et al., 1997:536; Myers, 1999:pl. 163 (LMM); Kuiter, 1998:209;? Hayashi & Shiratori, 2003:39 (x 2); Kimura & Matsuura, 2003:193; Allen et al., 2004:330; Kuiter & Tonozuka, 2004:707; Anderson, 2005:105; Randall, 2005:554.

Trimma sp. 9:? Senou et al., 2004:113 (x 2); Allen & Erdmann, 2012:948 (Red Sea to western Pacific)

Material. Australian Material. Queensland: Ashmore Reef: AMS I.33720-056, 2(10–11), 2–32 m; AMS I.33730-036, 8, 21– 32 m. Escape Reef: AMS I.22576-026, 3(23–27), 34 m; AMS I.22580-016, 2(21–22), 37 m; AMS I.22580-019, 2(17–18), 37 m; AMS I.22587-014, 2(23–24), 40 m; AMS I.22613-030, 25, 27 m; AMS I.22627-013, 4(21–23), 52–60 m; AMS I.22629-007, 3(22–24), 56–60 m; ROM 40468, 2(24–26), 40 m. Lihou Reef: WAM P.29638.016, 4(14–25), 20– 35 m. Lizard Id: AMS I.20730-006, 3(14–24), 20– 22 m. One Tree Id: AMS I.20206-014, (23), 22– 30 m. Raine Id: AMS I.20775-059, 3(9–21), 20 m. Tijou Reef: AMS I.20779-145, 2(13–15), 25 m. Yonge Reef: AMS I.19454-061, (26), 1– 18 m. W estern Australia: Rowley Shoals: WAM P.28024.021, (28), 35–40 m; WAM P.28024.033, (18), 35– 40 m.

Other material. Note: For AMS and ROM material, we provide catalogue numbers, number of specimens, length range and depth of capture where known. For other institutions, we list only catalogue number and number of specimens. American Samoa: AMS I.21988-002, 5(18–25), 58– 64 m. Carolines: BPBM 12169, 1; BPBM 22370, 1. Fiji: AMS I.18352-030, (21); ROM 46029, (13), 9–11 m; ROM 46030, 3(17–21), 10–15 m; ROM 46031, (16), 8–12 m; ROM 46032, (20), 5– 10 m. Indonesia: BPBM 26646, 2; BPBM 31517, 2; ex-CAS 64166, 1; ROM 64645, 2(12–15), 16 m; ROM 70715, 7(14–24), 30 m; ROM 70707, (22), 15 m; ROM 85131, 20(8–20), 20– 23 m. Japan: BPBM 8741, 11; LICPP 1970179, 4; LICPP 1971264, 1. Malaysia: ROM 56633, 2(20–25), 8 m. New Caledonia: ROM 63930, (24), 18–27 m; ROM 63931, (22), 18– 26 m. Palau: AMS I.17939–001, (22), 38 m; AMS I.17935–003, (16), 46 m; BPBM 31457, 3; CAS 60050, 27; ROM 70727, (22), 91 m; ROM 70730, 4(17–2), 91 m; ROM 70729, 16(14–29), 91 m; ROM 74794, 79(8–24), 14–26 m; ROM 74795, 74(8–24), 15–27 m; ROM 74796, 6(14–23), 31–43 m; ROM 74888, 58(8–23), 12–21 m; ROM 76100, 13(7–19), 15–31 m; ROM 76414, 11(8–20), 18–31 m; ROM 80312, 2(20–23), 12–26 m; ROM 80321, (17), 0–7 m; ROM 80325, 2(12–16), 37–46 m; ROM 80024, 2(21–28), 12 m; ROM 80305, 2(16–18), 27–42 m; ROM 80357, 2(12–20), 73 m; ROM 80363, 3(17–21), 17 m; ROM 80390, 62(8–22), 20–27 m; ROM 80400, 5(14–20), 20–27 m; ROM 80417, 9(9–19), 24–37 m; ROM 81939, 3 (7–16), 15 m; ROM 82404, 8(10–21), 50 m. Papua New Guinea: Bismarck Archipelago, Rabaul: ROM 88119, 4(16–19), 19.5 m; ROM 88123, 7(15–21), 27 m; ROM 88124, 5(17– 19), 19.5 m; ROM 88140, 3(18–10), 19.5 m; ROM 88143, 4(16–19), 17.7 m; ROM 88153, 2(20), 15 m; ROM 91272, 3(15–17), 30.5 m; ROM 92091, 2(16–17), 13.4 m; ROM 92109, (21), 20.7 m; ROM 92112, 2(18–20), 18.3 m; ROM 92117, (15), 27.7 m; ROM 92121, (15), 20 m; ROM 92124, (16), 31.4 m; ROM 92129, 3(21–22.0), 25.6 m; ROM 92137, (8), 15 m; ROM 92139, 5(16–19), 22 m; ROM 92152, 3(16–18), 18.2 m; ROM 92169, (18), 11.9 m; ROM 92182, 10(13–25), 26.8 m; ROM 92246, 3(16–19), 19.5 m; ROM 92253, (14), 18.9 m; ROM 92259, 3(16–18), 23.7 m; ROM 92271, 3(19–20), 17.1 m; ROM 92277, 3(13–20), 21.3 m; ROM 92285, (19), 17.8 m; ROM 92290, 4(18–19), 15.2 m; ROM 92304, (17), 16.5 m; ROM 92313, (19), 19.8 m; ROM 92321, (21), 17.4 m; USNM 203436, (20), holotype; USNM 203437, 10(13–20), paratypes (from original description). Other PNG material: AMS I.24375-001, 11(13–20), 15 m; BPBM 32448, 3; BPBM 36880, 1; WAM P.28161.008, 9; WAM P.28170.001, 4; WAM P.28172.016, 9; WAM P.28178.013, 1; WAM P.28186.014, 1. Philippines: AMS I.21903-018, 4(9–20), 3–15 m; AMS I.21927-007, 17(8–23), 14–21 m; BPBM 28521, 5; LICPP 1984237, 4; LICPP 1983349, 2; LICPP 1977087, 1; ROM 49222, 11(12–22), 12–18 m; ROM 49223, 2(9–18), 12–20 m; ROM 53087, (25), 12–21 m; ROM 53088, 2(23–25), 12–18 m; ROM 53089, (24), 14–18 m; ROM 53090, 2(16–20), 5–12 m; ROM 53091, 8(15–23), 15–21 m; ROM 53092, 6(12–27), 24–37 m; ROM 53093, 6(9–17), 18–35 m; ROM 53094, 10(20–26), 15–26 m; ROM 53122, (23), 3–11 m; ROM 53095, 11(14–265), 9–23 m; ROM 53096, 7(10–24), 9– 21 m. Solomons: AMS I.39040-072, (23), 10–30 m; AMS I.39033-082, 5, 3– 17 m; AMS I.39005-065, (19), 35 m; ROM E, 4(10–27), 8 m; ROM 0839CS, 8(10–31), 20–22 m; ROM 46126, (18), 21 m; ROM 46130, 21(7–22), 18–22 m; ROM 46132, 12(11–22), 18– 22 m. Taiwan: BPBM 23375, 1. Tonga: USNM 341463, 2.

Diagnosis. A species of Trimma with a bony interorbital greater or equal to pupil diameter, a fully scaled nape, papillae in longitudinal row immediately below eye single or with two papillae in a vertical row but not in vertical rows of 3–5 papillae each, usually unbranched pectoral-fin rays, an unbranched fifth pelvic-fin ray that is about 50% the length of the fourth ray, and a large dark blotch on the posterior caudal peduncle. Fresh, mature specimens> 20 mm SL may have a blue or purple stripe along the midline of the body reaching to the dorsal margin of the pupil, and another in the dorsal midline from the tip of the snout to the origin of the first dorsal fin.

Description. The description is based on five lots, 14 specimens (13.5–25.5 mm SL) from the northern Great Barrier Reef. Dorsal fin VI + I 8, second spine slightly to moderately elongated, reaching to between base of dorsal spine of second dorsal fin and that of third ray), all fin rays branched except for posterior element of last; anal fin I 8, first ray usually unbranched (12 of 14); pectoral fin 13–15 (mean = 14.4, n = 14), rays usually unbranched, but 1–4 of middle rays branched in four specimens, all> 20 mm SL; pelvic fin I 5, fifth ray unbranched (left side branched once dichotomously in largest specimen) and about 42–62% (mean = 54.1, n = 7) length of fourth ray, which reaches posteriorly to between bases of anal spine and third ray, basal membrane 6–11% (mean = 9.0, n = 9) length of fifth ray. Lateral scales 23–24 (mean = 23.3); transverse scales 7–8 (mean = 7.8, n = 12); predorsal scales 11–12 (mean = 11.5, n = 13); breast and midline of belly with cycloid scales; 5–10 scales present on pectoral-fin base; cheek scaled, usually with three rows of cycloid scales below and behind eye, 6–8 scales in middle row, upper row of 0–1 and lower row of 2–4 scales; opercle with at least three horizontal rows of cycloid scales. Single row of small, closely spaced, pointed teeth around lower jaw with additional outer row of larger, widely spaced, curved teeth; two rows of small, closely spaced pointed teeth in upper jaw. Tongue rounded. Gill opening extends anteroventrally to below mid-pupil; gill rakers 3–5 + 15–17 = 19–21 (mean = 3.8 + 15.9 = 19.8, n = 13). Anterior nares in short tube, posterior opening pore-like with raised rim, nasal sac raised and positioned close to upper lip. Bony interorbital 70–100% (mean = 83.6) pupil diameter; shallowly concave with median fleshy ridge forming broadly rounded W in cross section; epaxialis extending anteriorly to point above posterior half of pupil. Abdominal/caudal vertebral transition not examined (but probably Type A with haemal arches of first three caudal vertebrae expanded, as in other specimens currently identified as this species).

Colour pattern. Freshly collected. Body yellow, heavily invested with dark subdermal chromatophores, especially below midlateral septum ( Fig. 49 ). Pale blue stripe, lying just above midlateral septum and tapering at both ends, from just behind eye at level of dorsal margin of pupil and fading out at about mid-length of caudal peduncle. A white, slightly oblique, bar about two scales wide posteriorly, thinning ventrally, broadening to about four scales wide just above midline, then narrowing to two scale widths dorsally. Large (slightly greater than eye diameter) dark red spot, much darker towards centre, covers hypural region of peduncle and proximal bases of caudal-fin rays. Blotch extends further anteriorly on lower half of body, giving anterior margin notched appearance. Iris yellow with dark mottling, with red margined blue stripe across it at level of upper pupil. Tips of jaws, upper cheek and opercle yellow, faint blue stripe below this on cheek bordered dorsally with red. Ventral margin of cheek below suffused with yellow. Scattered dark chromatophores form diffuse bar on base of pectoral fin, and tips of pelvic-fin rays tinged with mauve. Dorsal fins with dark purple basal band sprinkled with melanophores and iridocytes, followed by pupil-diameter wide yellowish stripe (broader posteriorly in both fins), distal part of fins mauve with liberal sprinkling of iridocytes. Caudal and anal fins mauve to bluish-purple, with pupil-diameter wide basal stripe of purple/red in anal fin. No underwater photographs of live specimens from Australia available. Pair of individuals with almost identical colour pattern from Biak, Indonesia shown in Pl. 4 A.

Preserved. Background colour light brown with scale pockets heavily outlined on dorsal portion of body, particularly beneath dorsal fin base. Scale pockets immediately above mid lateral septum very faintly outlined, and scale pockets below mid lateral septum more strongly outlined, forming light band down side of body midlaterally. Snout very heavily pigmented. Some scattered pigment present along ventral edge of eye, cheek below immaculate or almost so. Tip of lower jaw with scattered melanophores, most of ventral surface of body immaculate. Blotch on caudal peduncle dark brown, and covers posterior section of caudal peduncle and base of caudal fin.

Etymology. Named after the American research vessel “Te Vega”, a converted luxury yacht, operated at the time the type specimens were collected by Stanford University's Hopkins Marine Station.

Distribution. The distribution is difficult to determine because of questions as to the potential confusion revolving around the taxonomy of this species (see Discussion). The blue striped form appears to range from the middle reaches of the Red Sea through the Maldives (but not south of this in the Indian Ocean) to the western Pacific as far east as the Marshall Islands and Samoa ( Fig. 50 ).

Comparisons. Among the described species of Trimma possessing a broad bony interorbital Trimma tevegae , T. griffithsi and T. nasa all have a dark spot on the hypural region of the caudal peduncle. Trimma griffithsi and T. nasa can be distinguished from T. tevegae in having a branched fifth pelvic ray, no scales on the cheek, and cycloid scales on the nape (vs. fifth ray unbranched, cheeks scaled, and ctenoid scales on the nape). The caudal spot on Trimma griffithsi is much smaller and positioned on the lower half of the peduncle. Trimma nasa has a very light colouration with much less pigment on the body compared with T. tevegae , except for a dark ‘shadow’ created along the side by pigment on the peritoneum. Trimma tevegae is more heavily pigmented along the dorsal surface than T. nasa .

Discussion. Trimma tevegae has previously been defined by a broad bony interorbital, scaled nape, unbranched fifth pelvic ray and the large dark patch on the posterior caudal peduncle. Variation in cheek scalation, snout stripe and lateral stripe were commonly seen within specimens from a single collection and across its extensive geographic range ( Winterbottom, 2005b). Results of recent genetic studies, however, have caused its specific status to become a morphological Pandora's Box. The situation is extremely complex, and the reader is referred to Winterbottom et al. (2014) for details. Suffice it to say that we suspect the Australian material will be found to share the same haplogroup as Group 4 of Winterbottom et al. (2014), which is currently known from samples from Raja Ampat, Indonesia and Rabaul, New Britain.

This species, to which we provisionally apply the name Trimma tevegae , has been collected at depths of 12– 73 m. The type material was collected in depths of 12–15 m, and Cohen and Davis (1969:317) state that small groups of this goby were observed at the type locality (Dawapia Rocks, Rabaul, New Britain) in depths of 9– 30 m.

Figures

FIGURE 49. Trimma tevegae, 23.2 mm SL male, AMS I. 20779 - 145, Tijou Reef, Queensland. Photo by D. F. Hoese.

FIGURE 50. Distribution map for Trimma tevegae (solid circles with white stars) and T. unisquame (solid squares with white circles). A hollow square with an X indicates localities at which both species occur.