Trimma annosum Winterbottom, 2003

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 : 11-14

Trimma annosum Winterbottom, 2003

Grey-bearded Pygmygoby

Figs. 3–4 , Pl. 1 B

Trimma annosum Winterbottom, 2003:2 , figs. 1–2 (Cagilai Id off Ovalau Id, Viti Levu, Bau Waters, Fiji); Allen & Erdmann, 2012:935 ( Maldives and western Pacific); Motomura et al., 2013:333 ( Japan).

Trimma sp. 2: Randall et al., 1997:408 (Great Barrier Reef).

Trimma sp. 8: Kuiter & Tonozuka, 2001:705 (live individual from Bali).

Trimma sp. 9: Allen, 1993: 88 ( Ashmore Reef).

Australian material. Queensland: Ashmore Reef: AMS I.33743-061, 4(8–16), 3– 13 m. Cape Melville, outer reef off: AMS I.20774-114, 45(9–20), 0– 8 m. Cape York, False Orford Ness: AMS I.20776-050, (10), 0– 4 m. Escape Reef: AMS I.22574-032, 4(9–20), 3–6 m; AMS I.22582-053, 2(15–17), 14–17 m; AMS I.22583, 2(8–15), 29 m; AMS I.22619-039, (20), 19–22 m; AMS I.22621-040, 2(16–19), 5– 8 m. Great Detached Reef: AMS I.20756-092, 38(10–16), 2– 8 m. One Tree Id: AMS I.20201-011, 5(13–19), 1–2 m; AMS I.20210-021, (16), 1–2 m; AMS I.20211-023, (13), 0–2 m; AMS I.20211-047, (13), 0–2 m; AMS I.20212-022, 2(14–17), 12–15 m; NTM S.11061- 0 10, (18). Osprey Reef: AMS I.25109, 2(15–17), 1–3 m; AMS I.25110-037, (19), 2–8 m; AMS I.33719-038, 3(14–16); 5–11 m; AMS I.33749-127, 10(14–20), 2– 6 m. Portlock Reef: AMS I.33752-059, 2(8–14), 12– 16 m. Raine Id: AMS I.20775-057, 13(12–18), 0–20 m; AMS I.20775-153, 3(12–16), 0–20 m; AMS I.20757-084, 59(11–19), 0– 20 m. Tijou Reef: AMS I.20779-150, 4(14–19), 0– 25 m. Yonge Reef: AMS I.18740-075, 2(14–28), 9–12 m; AMS I.19456-075, 21(10–20), 5–15 m; AMS I.19481-042, 2(12–15), 2– 6 m. Western Australia: Timor Sea, Ashmore Reef: NTM S.11973–[ex 053], 2(16–17). Christmas Id: WAM P.26102-023, (19), 6–8 m; WAM P.26120-014, (19), 3–4 m; WAM P.26109-006, (14), 6–7 m; WAM P.26122-008, (18), 8– 10 m.

Other material. The following are new localities for the species from which we have examined specimens, or from which we have taken data. Fiji: Bega Lagoon: AMS I.18448–032, 2(8–10), 1– 6 m. Great Astrolabe Reef: ROM 45971, 13(14–23), 1–4 m; ROM 45972, 1(19), 10–20 m; ROM 45974, 4(17–21), 2– 7 m. Nagau Id: ROM 45961, 3(16–19), 3– 9 m. Suva Harbour: AMS I.18354-115, 2(14–17), 6 m; ROM 45976, 13(9–18), 10– 14 m. Viti Levu: ROM 40061, 5(12–18). Indonesia: Ambon: USNM 396715, 18(12–17), 2 m; USNM 298791, 2(13–15), 11– 18 m. Bali: NTM S.11203-038, 10(11–24), 12 m. Banda Ids: USNM 298788, 2(13–15), 3–9 m; USNM 298806, 5(9–16). Ceram: USNM 210185, 2(15–16), 0– 1 m. Haruku Id: USNM 209593, 24(9–16), 5 m. Raja Ampat Id: ROM 84912, 1(14), 5 m; ROM 85050, 1(13), 15–40 m; ROM 85060, 1(13), 16–22 m; ROM 85169, 3(9–17), 2–5 m; ROM 85286, 1(15), 2–28 m; ROM 87425, 8(13–18), 6–21 m; Kiribati: Abaiang Atoll: AMS I.18039-025, 5(15–18), 1–4 m; AMS I.18043-073, (19), 5–8 m; AMS I.18044-041, (14), 9 m; AMS I.18046-035, 3(17–18), 2–5 m; AMS I.18047-043, 8(14–19), 2–5 m; AMS I.18050-061, 2(12–14), 12 m; AMS I.18051-066, 2(17–18), 11 m. Palau: Main Ids: ROM 74964, 38(9–17), 3–7m; ROM 74757, 23(9–16), 6–11 m; ROM 74758, 11(9–19), 6– 9m; ROM 74759, (15), 0–8 m; ROM 76078, 8(14–18), 0–8 m; ROM 76079, 2(15–17), 15–24 m; ROM 76080, 9(14–20), 0–7 m; ROM 76081, 15(9–17), 3–7 m; ROM 76418, (10), 15–18 m; ROM 76446, 7(10–16), 0–9 m; ROM 76427, 10(11–17), 15–21 m; ROM 76447, 7(12–18), 3–8 m; ROM 80320, (15), 0–7 m; ROM 80333, 4(9–17), 8–12 m; ROM 80323, 6(11–17), 3–9 m; ROM 80375, 15(13–18), 14–18 m; ROM 80362, 9(14–17), 0–5 m; ROM 80433, 6(11–16), 0–7 m; ROM 80435, (12), 24–34 m; ROM 80446, 27(10–17), 5–18 m; ROM 80463, 23(12–18), 7–17 m; ROM 80477, (15), 9–21 m; ROM 80509, 16(13–19), 2– 6 m. Ponape: USNM 298763, 2(11–15), 0–16 m; USNM 298764 [ex 223269], 9(10–19), 0– 1 m. South West Ids: ROM 82988, 4(8.1–14.0), 20–36 m; ROM 82996, 3(17.7–18.3), 16–33 m; ROM 83005, 2(17.7–18.5), 16–33 m; ROM 83026, 5(15.6–21.4), 7–15 m; ROM 83040, (17.7), 20–35 m; ROM 83046, (15.4), 12–30 m; ROM 83059, (14.9), 18–30 m; ROM 83081, (16.1), 2–8 m; ROM 83253, (10.3), 4–25 m; ROM 83397, (16.2), 22– 35 m. Papua New Guinea: Bagabag Id: USNM 298781, 2(15–18), 6– 12 m. Coral Sea, Eastern Fields Atoll: NTM S.12230–004, (10) 6– 18 m. Hermit Ids: USNM 298799, (20), 0– 12 m. Louisade Archipelago: USNM 245213, (19), 0– 6 m. Massas Id: USNM 262633, (16), 0– 18 m. Madang Harbour: USNM 295299, 2(14–15). New Ireland: USNM 298782, 2(18–19), 0– 10 m. New Britain: USNM 203311, 2(16–18), 1– 2 m. Ninigo Ids: USNM 244077, (17), 0– 6 m. Port Moresby: NTM S.12243- 0 0 2, (10), 9– 24 m. Trobriand Ids: AMS I.17094-030, 3(12–15), 0–5 m; USNM 298784, 9(12–16), 0– 10 m. Umboi Id: USNM 244165, 3(8–15), 0–4.5 m. Philippines: Batan Id: USNM 293343, 4(18–21), 9– 12 m. Cebu: ROM 49225, 2(17–21), 0–2 m; ROM 53152, 6(16–20), 3– 11 m. Mindanao: USNM 263475, 25(14–19), 0– 5 m. Mindoro: LACM 42490 [ex –77], 1(15); LACM 42491–[ex–76], 3(15–17). Negros: ROM 53150, 1(20), 0–5 m; USNM 263472, 15(14–21), 0– 3 m. Sombrero Id: AMS I.21915-053, 8(10–19), 6 m. Solomon Ids: Guadalcanal: AMS I.17486-057, 3(18–18), 2– 4 m. Savo Id: AMS I.17491-037, 1(14), 10 m. Florida I: AMS I.17497-022, (18), 2– 5 m. Taiwan: Ch'uan-Fan-Shih: USNM 263455, 2(20–22), 8–9 m; USNM 263460, 3(18–23), 0–6 m; USNM 295308, 2(19–20), 8– 9 m. Mao-Pi T'ou: USNM 263473, 1(21), 12– 13 m.

Diagnosis. A species of Trimma with a shallow concave bony interorbital about half pupil-diameter in width; predorsal completely covered with ctenoid scales, with no naked patches, a large scale above and between the end of the eyes above the posterior half of the pupil; cheek naked; operculum usually with a single large ctenoid scale dorsally, often followed by a smaller cycloid scale posteriorly; pectoral-fin base with 3 large vertically elongate cycloid scales; prepelvic area with 4–5 rows of cycloid scales, 1 enlarged scale between the bases of the pelvic spines, pectoral rays normally unbranched, rarely with up to 4 rays with a single branch; fifth pelvic-fin ray branched once dichotomously, rarely branched twice resulting in 3 terminal tips, and 40–65% the length of the fourth; no trough or groove posterodorsal to the eye; second and third dorsal spines subequal in length, none elongated; head bluish grey, cheek uniform colour, in life a yellowish orange spot about the size of the pupil on the middle of the anterior part of the operculum, a similar sized spot dorsally and posteriorly on the operculum, a smaller yellowish orange spot behind eye; an oval yellowish orange to reddish orange spot centrally on the pectoral base; body with moderate sized yellowish orange spots in 4 rows anteriorly converging to 3 on the caudal peduncle; body fully scaled; no nape crest; dorsal and anal rays usually I 8.

Description. The description is primarily based on specimens from the Great Barrier Reef. Dorsal fin VI + I 8 (rarely I 7 or I 9 in 3.4% of individuals, mean = I 8.0, n = 202), second to fourth rays longest and subequal in length, reaching to between bases of first to second segmented dorsal-fin rays when adpressed, first ray of dorsal fin usually branched, anterior element of last element branched; anal fin I 8 (rarely I 7 or I 9, in 5% of individuals, mean = I 8.0, n = 202), first ray unbranched, anterior element of last ray branched; pectoral fin usually 18 (in 60 % of individuals), 16 in 1% of individuals, 17 or 19 in 39% of individuals, mean = 18.0, n = 189), reaching just posterior to a vertical in line with anal spine, rays usually unbranched (rarely with 3 branched rays, beginning at fifth from top in 2 of 80 specimens examined); pelvic fin I 5, first four rays with 1 sequential branch, fifth ray with one dichotomous branch (two terminal tips), 40–65% the length of the fourth ray, which reaches posteriorly to anterior few elements of anal fin; fraenum absent, basal membrane present, variably present in preserved specimens, from just connected to basal 10% of fifth ray to tip of fifth ray, but often torn and low values possibly not normal. Lateral scales 22–25 (mean Australia = 23.0, n = 89, non Australian specimens 23.3, n = 68, largely due to high counts of 11 Fiji specimens); transverse scales usually 7, (rarely 6 in <1% of individuals, mean = 6.9, n = 130); midline predorsal scales 4–7, 5 in 92% of specimens, mean 5.0, n = 168); scales on pectoral-fin base, breast, and sometimes anteriormost 1–2 scales on midline of belly cycloid, remaining scales ctenoid; scales extending anteriorly to just behind eye; scales below posterior end of second dorsal fin with small accessory scales; pectoral-fin base with 3 large vertically elongate cycloid scales; prepelvic area with 4–5 rows of cycloid scales. Teeth in lower jaw consist of an enlarged outer row of curved, spaced canines and an inner row of similar, but smaller, canines with irregular rows of small conical teeth in between; outer row of teeth in upper jaw similar to those of lower jaw, with small irregular inner rows of teeth. Tongue tip truncate to slightly emarginate, no central point. Gill opening extending anteroventrally to below posterior margin of pupil to mid pupil; gill rakers on first arch 2–4 + 10–14 = 12 –17 (mean = 14.5, based on 56 specimens). Winterbottom (2003) reported 2–3 + 10–12 = 12–15 (mean = 14.1, n = 15). Anterior nares a narrow tube, posterior nares a large pore with a raised rim; nasal sac slightly elevated as a raised oval sac located midway between orbit and upper lip. Interorbital trough moderate, often just reaching upper posterior margin of eye, posterodorsal trough otherwise absent, bony interorbital width about one third to half pupil diameter. Posterior abdominal/anterior caudal vertebral pattern is Type B.

Colour pattern. Freshly collected. From slides of freshly collected specimens from the Great Barrier Reef ( Fig. 4 ). Three to four rows of yellow to orange spots on a dirty white to grey background; rows of spots loosely defined, and not vertically aligned, but forming longitudinal lines on caudal peduncle, with uppermost row close to dorsal surface. Spots on caudal fin, and a row of spots just above base or a basal stripe present on dorsal fins, colour of paired fins yellow to orange. A single yellow-orange round or oval blotch (usually vertically oriented) present on pectoral-fin base and two other such blotches occur on upper and at anteriormost portion of opercle. A smaller spot, about half pupil diameter in width, present immediately posterior to eye and in line with pupil. Cheek uniform grey to bluish-grey with no bars or spots. Scale pockets strongly outlined with pigment, usually melanophores, but sometimes yellowish chromatophores; a diffuse, yellow to orange ring around the pupil. Photographed freshly collected specimens from other localities may have red (rather than yellow/orange) markings on head, body and fins, as is evident in live specimen from Raja Ampat (Pl. 1B).

Preserved. Background colour straw yellow with brown chromatophores. Scale pockets strongly outlined on head and anterior portion of body on some specimens. Area between light spots on body forming grey lines, better developed anteriorly. Cheek and snout uniformly dusky. First dorsal fin with a sprinkling of melanophores; second dorsal fin with two dark stripes, one basal, one in middle of fin; anal fin with a basal stripe and a second almost distal stripe. Pectoral fins often hyaline, but some specimens have melanophores along fin rays. Some pigment is also present on outer fin rays and membranes of pelvic fins. Large light spots on head and body, six or seven large (pupil size) spots along top third of the body. Four spots are immediately adjacent to two dorsal fins, and two spots on upper half of caudal peduncle. These spots usually joining at dorsal surface to create a series of saddles. Second and third rows of spots not as distinct as uppermost row and often appear more like random blotches on the body. Four single spots on opercle, pectoral-fin base and behind the eye in freshly collected specimens present in preserved material as light brown spots.

Variation. Samples of more than 20 specimens were available from the Great Barrier Reef, Fiji, the Philippines and Kiribati. Analysis of that data shows no significant differences between the populations in fin-ray and scale counts. The maximum size known is 28 mm SL, but from most samples the maximum size is around 20–22 mm SL.

Colour varies slightly in individuals from the Great Barrier Reef. The reddish-orange spot on the base of the pectoral fin varies from oval and vertically elongate to round, covering between one-third and one half of the pectoral-fin base. The bluish grey lines on the body vary from only being present anteriorly on the body (with the caudal peduncle almost totally yellowish orange) to the lines extending to the end of the caudal peduncle with distinct yellowish orange spots on caudal peduncle. The body colour can vary from reddish orange to yellowish orange and the light head and body spots vary from yellow to bright red.

Etymology. From the Latin ‘annosum’, full of years, long lived, aged; in allusion to the plain grey cheek of the new species, which is perhaps reminiscent of some elderly, bearded human males.

Distribution. Trimma annosum is abundant on the Great Barrier Reef, and is currently known from One Tree Island on the southern part of the reef and from Escape Reef to Tijou Reef on the northern part of the reef. It is also found on islands of the Coral Sea and Ashmore Reef in the Timor Sea. It is normally confined to offshore reefs along the eastern edge of the Great Barrier Reef and is not normally found on mid reefs and never from coastal reefs. In Australia it is most abundant in depths of 1–10 metres, but has been found to almost 30 m. Outside of Australia the species was found in similar clear water reefs over a similar depth range. The species is known from the Maldives and Christmas Island in the Indian Ocean, northward to Taiwan and eastward to Fiji, the Caroline Islands and Kiribati ( Fig 3 ). Specific locations outside of Australia include Bali, Moluccas, Papua New Guinea, Micronesia, Kiribati, Palau, China, Taiwan, Fiji, Philippines, Solomon Islands, and Vietnam.

Comparisons. Winterbottom (2003) compared the species to Trimma maiandros (as Trimma DFH sp. 17) and T. okinawae , which have a colouration that can be confused with this species. Both have some reduction in predorsal scales. In having a depressed head, uniformly dark coloured cheek, opercular scales, fully scaled predorsal and dorsal and anal-ray counts the species is most similar to members of the Trimma emeryi complex, which in Australia includes Trimma emeryi and Trimma pentherum sp. nov. In life the three species are easily separated: Trimma emeryi is most easily distinguished by the uniform body colouration without yellowish or reddish-orange spots. Trimma pentherum sp. nov. differs in having a large black bar on the pectoral base. Trimma annosum is also similar to T. flavicaudatum ( Goren, 1982) from the Red Sea, which has large red spots on the head. The DNA analysis of 14 specimens ( Taiwan, 4; Palau, 4; Raja Ampat, Indonesia, 4; Great Barrier Reef, 2) show very modest variation in the CO1 sequences (0.7%) across this extensive range.

Discussion. This species has been referred to informally as Trimma DFH sp. 9. It has been collected in depths from 5– 60 m. In Australia it is known only from outer barrier reef islands to 29 m, and on the reefs in the Coral Sea from 1– 20 m.

Figures

FIGURE 3. Map of the distributions of Trimma anaima (solid circles) and T. annosum (solid triangles). A black star indicates localities at which both species occur.

FIGURE 4. Trimma annosum, AMS I. 20757 - 084, Raine Id, Far Northern Queensland. Photo by D. F. Hoese.