Trimma trioculatum, Winterbottom, Richard, Erdmann, Mark V. & Dita Cahyani, N. K., 2015

Winterbottom, Richard, Erdmann, Mark V. & Dita Cahyani, N. K., 2015, New species of Trimma (Actinopterygii, Gobiidae) from Indonesia, with comments on head papillae nomenclature, Zootaxa 3973 (2), pp. 201-226 : 217-225

Trimma trioculatum sp. nov.

Three-eyed pygmy goby Figs. 12–18

Trimma sp: Allen et al., 2003:329

Trimma sp 1: Allen & Erdmann, 2012:946

Material. The type material is restricted to specimens collected in Cendrawasih Bay, which forms the eastern and northwestern margins of West Papua and Papua provinces, Indonesia, respectively.

Holotype. ROM 98816, 16.5 mm SL female, Indonesia, West Papua, Cendrawasih Bay, Mark's Delite, about 45 kms E of Pulau Roon, (02°25.833'S, 134°59.366'E), 20 m, clove oil, 13 May, 2014, M.V. Erdmann.

Paratypes. MZB 22715, 15(16.7–17.5, ex- WAM P.33043.001), Tridacna Atoll, outer reef, (02°30' S, 134°59' E), 20–60 m, CB 08–005, 8 Nov., 2008, G.R. Allen & M.V. Erdmann. ROM 95249, 13(11.3–19.4), collected with holotype. ROM 93648, 6(14.9–17.2), Mark’s Treasure, (02°25.830'S, 134°59.409'E), 45m, clove oil, 15 Jun., 2012, M.V. Erdmann. ROM 95778, 2(13.1–14.7), Tridacna Atoll, (02°29'37.6"S, 134°58'59.4"E), 50 m, clove oil, 15 Jul., 2013, M.V. Erdmann. WAM P.33043.001, 15(15.4–18.2), data as for MZB 22715. WAM P.33357.007), 13(9.4– 18.0), Tridacna Atoll, outer reef, (02°30'S, 134°59'E), 70–71 m, CB 10-002, 1 Sept., 2008, G.R. Allen & M.V. Erdmann.

Non-type material. Indonesia: Bali: ROM 94022, (17.5), Pulau Menjangan, (08°05.813'S 114°31.608'E), 8 m, 14 Sept., 2012, M.V. Erdmann. ROM T 012754, (20.2), as for ROM 94022. Sulawesi: ROM 94884, 5(16.8– 21.9), North Sulawesi, Bunaken I., Fukui, cave with silt, (01°36.755'N, 124°44.333'E), 70 m, 2 Sept., 2013, M.V. Erdmann. Palau: ROM 74797, 5(15.2–17.1), Uchelbeluu Reef (aka Short Drop Off), (07°16'29.2"N, 134°31'32.1"E), 14–26 m, 21 May, 2004, R. Winterbottom et al. ROM 80393, (19.8), Uchelbeluu Reef, (07°16'28.7"N, 134°31'32"E), 20–27 m, 31 Mar., 2006, R. Winterbottom et al. Papua New Guinea: New Britain, Rabaul: ROM 92317, (16.2), Dawapia Rocks, (04°14.185'S, 152°09.980'E), 17 m, 26 Nov., 2011, R. Winterbottom & W. Holleman. ROM T13200 , (16.2), as for ROM 92317. WAM P.28170–004, (17.7), six kilometers south east of Rabaul, near Bai village at steep dropoff (04°11'S, 152°12'E), 25–34 m, 0 7 Oct., 1983, G. Allen. Hermit Is, Amot I. USNM 263453, 2(13.1–15.2), ocean side of reef on drop-off (01°33'S, 144°59'E), 0–46 m, 31 Oct., 1978, Springer et al. Philippines: Balacasag I. USNM 258622, (18.9), west side at drop-off (09°31'14"N, 123°40'00"E), 0–24.4 m, 10 Jun., 1978, Springer et al. USNM 263467, 7(14.0–20.6), W side at drop-off, (09°31'14"N, 123°40'00"E), 0– 24 m, 10 Jun., 1978, Springer et al. USNM 263468, (19.1), W side at drop-off, (09°31'14"N, 123°40'00"E), 0–41 m, 11 Jun., 1978, Springer et al. Cebu: Caceres Reef: USNM 263521, 5(15.1–18.6), near Huisan Point, east coast of Cebu, 24.4–30.5 m, 18 May 1979, J. Libbey et al. Cebu: Mactan I: ROM 49217, (13.2), off Hudson Beach, (10°15'N, 124°00'E), 12–20 m, 7 Aug., 1985, R. Winterbottom & E.O. Murdy. ROM 49218, 2(8.8–17.7), off Hudson Beach, (0°15'N, 124°00'E), 12–18 m, 8 Aug., 1985, R. Winterbottom & E.O. Murdy. Negros Oriental: ROM 53062, (17.5), Bais Bay near main channel, (09°36'54"N, 123°11'06"E), 18–35 m, 19 May, 1987, R. Winterbottom et al. Siquijor Island: ROM 53059, (20.9), Tonga Point, (09°12'16"N, 123°26'48"E), 14–18 m, 8 May, 1987, R. Winterbottom et al. ROM 53060, (18.2), Tonga Point, (09°12'16"N, 123°26'48"E), 5–12 m, 9 May, 1987, G.D. Johnson et al. ROM 53061, 10(17.2–21.8, one specimen 20.3, cleared and stained, ROM 1410CS), Tonga Point, (09°12'16"N, 123°26'48"E), 15–21 m, 12 May, 1987, R. Winterbottom et al. ROM 53064, 3(17.9– 19.0), Tonga Point, (09°12'16"N, 123°26'48"E), 9–21 m, R. Winterbottom et al., 22 May, 1987. USNM 263561, 2(18.0–20.0), 2 km W of town of Siquijor, (09°13'30"N 123°29'E), 24.4–30.5 m, 14 May 1979, J. Libbey et al.

Diagnosis. A species of Trimma with a large (slightly greater than pupil diameter in width) round, black, ocellated spot in the first dorsal fin between spines 1 and 5, a second, much smaller black or dark red spot just posterior to the spine of the second dorsal fin and above the basal stripe, a yellow body with a dark purplish or gray head with two distinct red bars across the cheek, no round spots of any colour on the nape, opercle or cheek, a small dark (preserved) or white (alive) spot on the upper pectoral fin base, a narrow bony interorbital (<70% pupil diameter), no elongate spines in the first dorsal fin, 15–16 pectoral fin rays with the middle 4–8 rays branched, a fifth pelvic fin ray with a single dichotomous branch, and 16–17 total gill rakers on the first gill arch.

Description. Based on the holotype and 10 specimens (15.4–19.4 mm SL) from ROM 95249. Dorsal fins VI + I 8– 9 (mean = 8.8), second spine longest and reaching to between base of first to third elements of D2 when adpressed, first ray of second dorsal fin unbranched, (once branched), posterior element of last dorsal ray unbranched, last ray reaching posteriorly 28– 37.4 –44% (mean = 35.7%) of distance between its base and first dorsal procurrent caudal ray; anal fin I 8, first ray unbranched, as is posterior element of last ray, which reaches posteriorly 29– 34.8 –43% (mean = 33.8%) distance between its base and first ventral procurrent caudal ray; pectoral fin 15– 16 (mean = 15.8), 4 –7 dorsal and 4– 5 –6 ventral rays unbranched, total unbranched rays 8– 9 –12 (mean = 9.7) with 4– 7 –8 (mean = 6.1) branched rays, fin reaching posteriorly to above first, second or third anal fin element; pelvic fin I 5, first four rays with one sequential branch, fifth ray unbranched and 41– 43 –54% length of fourth (mean = 47.7%), fourth ray reaching posteriorly to between bases of first to sixth anal fin elements; no fraenum; basal membrane vestigial (<7% length of fourth ray—Fig. 12, red arrow) or not crossing midline and attached to side of body beneath last pre-pelvic scale. Lateral scales 23; anterior transverse scales 8 (once 9); posterior transverse scales 7– 8; predorsal scales 7– 8 (mean = 7.7); scales extending anteriorly on sides of nape to just behind eye, scales on cheek apparently absent; opercle with 1–2 rows of 3 and 1–2 cycloid scales respectively or with larger scales ctenoid; pectoral-fin base margined posteriorly with two vertical rows of 3 –4 scales in outer row and 1– 2 in inner row; scales anterior to pelvic fin 6– 7 (mean = 6.7), scales on pectoral-fin base, breast, anterior midline of belly and anterior nape cycloid, others ctenoid. Upper jaw teeth with outer row of about 8 evenly spaced, curved, enlarged canines decreasing in size posteriorly and extending almost to distal end of premaxilla, inner row of about 4 straight conical teeth about half size of outer row, ending before bend of premaxilla, 2–3 irregular rows of small conical teeth between these, grading to single row on posterior part of premaxilla. Lower jaw teeth with outer row of about 6 evenly spaced, curved, enlarged canines ending at bend of dentary, inner row of slightly enlarged and curved teeth which decrease in size posteriorly and end at coronoid process, 2–3 irregular rows of small conical teeth between these, grading posteriorly to single row and ending on anterodorsal tip of coronoid process of dentary. (Description of teeth based on a single, non-type cleared and stained specimen from the Philippines, ROM 1410CS). Tongue broadly truncate, often slightly concave in midline. Gill opening extending anteroventrally to below mid-pupil; outer gill rakers on first gill arch 3 –4 (mean = 3.2) + 13– 14 (mean = 13.6), total rakers 16– 17 –18 (mean = 16.8). Anterior naris short tube, separated from upper lip by its width, post naris small pore with a slight or no raised rim and more or less flush with surface of snout, separated from eye by 3–4 times its diameter, nasal apparatus small, confined to anterior one-third of snout ( Fig. 13 B). Bony interorbital width 37– 40 – 47% of pupil diameter in width (mean 41.1%), interorbital with moderately developed 'U'-shaped trench about as wide as deep, a shallow postorbital groove but not trench-like. Sensory papillae as in Figure 13 , number of papillae in each row given in Table 1 . No ridge of tissue (or dermal crest) extending anterior to first dorsal spine. Epaxialis reaching anteriorly to above vertical with posterior margin of pupil. Abdominal/caudal vertebral transition Type B, based on non-type, cleared and stained specimen (ROM 1410CS) from the Philippines ( Fig. 14 ).

Colour pattern, live and freshly collected, based on numerous photographs by G.R. Allen and M.V. Erdmann ( Fig. 15 ). Head (except opercular region) dark purplish-gray, lighter in juveniles, with two one-third pupil diameter red bars across cheek, first bar below anterior margin of pupil, second bar below posterior margin of pupil and may be slightly convex along its anterior margin; faint diffuse reddish marking may be present between eye and maxilla, remainder of cheek dark grey or purple (lighter in juveniles) sprinkled with dark chromatophores, larger within red bars than elsewhere on cheek; iris mottled with dark red and black or purple with thin white circle around iris; two to three red spots separated by lighter bluish-purple interspaces along dorsomedial margin. Opercular region and body yellow, scales on nape and upper body below first dorsal fin usually edged with darker pigment (less so in juveniles). First dorsal fin with large black spot (slightly greater in diameter than pupil) between spines 1–5, margined anteriorly and dorsally with white or light blue; remainder of fin yellowish with a diffuse basal band of iridocytes and dark chromatophores; distal margin of fin between spines 4– 6 may also have iridocytes and dark chromatophores. Second dorsal fin with similar basal and distal stripes, main body of fin translucent yellow; dark red or black round spot almost fills space between spine and first ray just above distal stripe. Caudal fin translucent, often with yellowish wash. Anal translucent yellow with leading and distal margins dirty white or pale blue. Pelvic and pectoral membranes translucent, pectoral rays yellow to reddish; white spot diffusely margined with melanophores on upper pectoral fin base.

Preserved colour. Background colour of head and body off-white ( Fig. 16 ). Cheek with many dark chromatophores except where red bars occurred, where pale with only a few chromatophores. Top of snout very heavily pigmented with dark chromatophores, nape and opercular region somewhat less so, with pigment concentrated on, but not confined to, scale margins on nape; behind this, dark chromatophores along scale margins with a few others scattered on body, amount of pigmentation decreasing posteriorly and ventrally. Large black spot in first dorsal still evident, but rest of fin hyaline except for a distal dusting of dark chromatophores. Black (or sometimes red in life) spot behind spine of second dorsal fin also present, as are dark chromatophores in basal stripe and along distal margin of fin. Caudal fin translucent with a few scattered chromatophores. Anal fin hyaline with darker basal and distal stripes. Pelvic fin with a few darker pigment cells basally. Pectoral fin membranes hyaline, a small concentration of dark chromatophores forming diffuse spot on dorsal base of fin.

Etymology. The name is derived from “tri” (three), and “oculatus” (having eyes) in reference to the extra apparent eye formed by the dark ocellated spot in the first dorsal fin. This species has been informally referred to as Trimma RW sp. 32.

Distribution. Positively known only from the northern portion Cendrawasih Bay, West Papua, Indonesia (see Discussion below, Fig. 18 ).

Comparisons. Only one other species of Trimma , T. zurae has a large, round, ocellated black spot in the first dorsal fin. In T. zurae , the black spot is about equal to the eye diameter in width (vs. slightly greater than pupil diameter), there are yellow spots on the nape, posterodorsal cheek and upper opercle (vs. such spots absent), there are no red bars on the cheek (vs. two such bars present), and there are 17–18 pectoral fin rays (vs. 15–16). In addition, the posterior nares of T. trioculatum lack a raised rim, and the nasal sac is not elevated above the surrounding surface of the snout (vs. posterior nares with a raised rim, nasal sac slightly raised above surrounding snout in T. zurae ). In T. irinae there is an ovoid dark basal spot in the first dorsal fin between spines 1–4, with a smaller rounded basal spot between spines 5–6. This species lacks the dark spot behind the spine of the second dorsal fin, has an elongate second dorsal spine reaching posteriorly to the end of, or beyond the second dorsal fin (vs. second spine not elongate), has round reddish spots on the posterior head and anterior body (vs. such spots absent), lacks bars on the cheek (vs. present), has a dark spot on the branchiostegal membranes (vs. such a spot absent), and has more total gill rakers (19–20 vs. 16–18). Trimma papayum Winterbottom, 2011 , also has one or two dark spots near the base of the first dorsal fin, but these are very small (about one-quarter pupil diameter in width vs. a single spot greater than pupil diameter in width), an elongate second dorsal spine in the first dorsal fin (vs. not elongate), orange spots on the opercle and nape (vs. such spots absent), and 18–19 pectoral fin rays (vs. 15–16).

Discussion. Winterbottom et al. (2014b) provided a BOL analysis of the CO1 gene based on four specimens identified as T. RW sp 32 from three localities. The results suggested that there were three haplogroups corresponding to the three localities, each group separated by a minimum of 7% of the genome from the others (Cendrawasih Bay, Group 1; Palau, Group 2; and Rabaul, Group 3). Additional localities for which no tissue samples were available include other islands within Indonesia (Bali, Sulawesi), the Philippines (several localities), the Hermit Islands and the Wallis and Futuna Islands (photograph only). A specimen from Sulawesi ( Fig. 17 A) is basically similar to the Cendrawasih Bay material, but the dorsal part of the body is partly translucent, giving it a mottled appearance, the bars on the cheek are much lighter red, and the area around the bases of the first three spines of the first dorsal fin is white (which continues dorsally to join the white ocellus around the dorsal black spot). A specimen photographed alive from Bali ( Fig. 17 B) has a brick-red body, with a dark grey-purple head. In two photographed specimens from Rabaul ( Fig. 17 C), the background colouration of the head is a whitish-grey (rather than dark purple) heavily invested with large dark chromatophores, and there is a red blotch at the posteroventral margin of the black ocellated spot in the first dorsal fin. No basal stripe is visible in either the dorsal or the anal fins. A specimen from Palau ( Fig. 17 D) has a dark grey head, with no trace of the white ocellation around the black dorsal spot, but the dark basal stripe is evident in the second dorsal fin. Specimens from the Philippines also tend to have a grey head and yellow body, but the white ocellation is clearly apparent, although one specimen has a brownish (rather than yellow) body dorsally, and the margins of the scales are red instead of black ( Fig. 17 E). A specimen from the Wallis Islands ( Fig. 17 6 F) is very similar to the type material, although the large dark chromatophores on the body extend further posteriorly and ventrally, and the scale margins are edged with red over most of the body.

No clear-cut differences in morphometric or meristic values between the Cendrawasih Bay specimens and those from other areas were apparent. However, three of eight specimens from the Philippines examined had one or both fifth pelvic fin rays branched, as did the single specimen from Bali and one from Palau. Further work on these aspects in conjunction with wider geographic sampling of tissues is needed to explore whether the differences in CO1 found by Winterbottom et al. (2014b) are supported by morphology, and to investigate whether there is any genetic connectivity between the various populations/species.

Specimens examined for this study were collected between 5– 71 m. The type series collected from Cendrawasih Bay were only found between 20–71 m depth (and never shallower). The habitat in Cendrawasih was consistently steep outer reef walls, with T. trioculatum often present in groups of up to 20 individuals loosely aggregated and perched vertically on the substrate at the back of small overhangs and crevices. Non-type specimens collected in Bali and North Sulawesi also were also nearly always found on steep outer reef walls in the same habitat as above.

Figures

FIGURE 12. Trimma trioculatum, 17.7 mm SL F, ROM 95249, Cendrawasih Bay, ventral view of pelvic fin and basal membrane, anterior to top. Red arrow points to junction between basal membrane and last prepelvic scale. Specimen stained with cyanine blue. Photo: R. Winterbottom.

FIGURE 13. Trimma trioculatum, details of head to show distribution of sensory papillae. A: Left lateral view, 16.8 mm SL female, ROM 95249, Cendrawasih Bay. B: Dorsal view, 19.4 mm SL female, ROM 95249, Cendrawasih Bay. Specimen stained with cyanine blue. Photos: R. Winterbottom.

FIGURE 14. Trimma trioculatum, 20.3 mm SL female, ROM 1410 CS, Philippines. Anterior view of 10 th abdominal (A) and 1 st caudal vertebrae (B). Abbreviations: C = centrum; HA = haemal arch; HC = haemal canal; HS = haemal spine; NA = neural arch; NS = neural spine; PR = pleural rib; SHC = secondary haemal canal. Specimen stained with alizarin red. Photos and image enhancement by R. Winterbottom.

FIGURE 15. Trimma trioculatum, Cendrawasih Bay. A: live specimen, juvenile (not collected). B: anaesthetised specimen, 16.8 mm SL female, ROM 95249. C: anaesthetised specimen, 18.0 mm SL female, ROM 95249 (note damaged dorsal fins). Photos: G. R. Allen (A); M. V. Erdmann (B & C).

FIGURE 16. Left lateral view of head and anterior body of preserved Trimma trioculatum, Cendrawasih Bay, to show pigmentation of head and dorsal fins (16.5 mm SL female, ROM 95249). Photo: R. Winterbottom.

FIGURE 17. Left lateral view of freshly collected, non-type specimens of Trimma trioculatum. A: ROM 94884, Bunaken Island, North Sulawesi. B: 17.5 mm SL, Menjangan Island, Bali. C: 16.2 mm SL male, ROM 92317, Rabaul, New Britain. D: 15.2 mm SL, ROM 74797, Palau. E: 17.7 mm SL female, ROM 94218, Mactan, Philippines. F: Wallis Island. Photos: M. V. Erdmann (A & B); R. Winterbottom (C – E); J. T. Williams (F).

FIGURE 18. Distribution of the three new species based on material examined for this study. Trimma aturirii, black inverted triangles. Trimma kardium, black diamonds. Trimma trioculatum, coloured pentagons. Blue fill, type locality, Group 1 haplogroup; green fill, Palau, Group 2 haplogroup; yellow fill, Rabaul, New Britain, Group 3 haplogroup; red fill, unknown haplogroup.