Trimma aturirii, 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 : 203-210

Trimma aturirii , sp. nov.

Aturiri’s pygmy goby Figs. 1 , 3–6 , 18

Material Examined. All type specimens are from the northern part of West Papua province, Indonesia. The description is based on up to 17 specimens, 14.0– 18.8 mm SL culled from all five lots.

Holotype. ROM 94889, (18.4 mm SL female), Mapia Atoll, south end of Pulau Pegun, (00°47.795'N, 134°18.198'E), steep wall covered with coarse white Halimeda sand, 60 m, clove oil, 2 Nov., 2013, M.V. Erdmann.

Paratypes. MZB 22713, 7(13.5–14.7, ex-ROM 87934,), Pulau Mof (north of Waigeo), (00°31.431'N, 130°44.020'E), 70 m, clove oil, 7 Mar., 2011, M.V. Erdmann. ROM 95269, 5(14.4–16.6), NW side of Ayau Besar Atoll, (00°35.729'N, 131°06.212'E), exposed oceanic atoll with clear water, steep outer wall with small crevices and overhangs, coarse white coralline sand, 38 m, clove oil, 1 July, 2014, M.V. Erdmann. ROM 98809, 10(11.0– 16.8), Ayau Besar Atoll, (00°36.306'N, 131°06.398'E), steep outer reef slope with white calcareous sand, 40 m, clove oil, 22 Oct., 2014, M.V. Erdmann. ROM 98853, 3(14.1–18.8),NW side of Ayau Besar Atoll, (00°35.177' N, 131°06.834' E,), 50 m, 19 Feb., 2015, MVE-15-010, M.V. Erdmann.

Tissue specimens (all from Ayau Besar Atoll, collected by M.V. Erdmann): MB0614201, 1 Jul., 2014; MB0615401, MB0615402, 22 Oct., 2014; ROM T19515, 19 Feb., 2015.

Diagnosis. A species of Trimma unique in the possession of two dark oblique stripes on either side of the pupil (blue, edged with red in life, dark brown in preservative), the lower of which continues posteriorly across the dorsal margin of the opercle. The dorsal half of the body is red and the ventral half abruptly white in life. The species has a narrow bony interorbital (≤50 % pupil width), a moderate interorbital trench with a slight groove posterodorsal to the eye, no scales on the cheek, opercle or in the predorsal midline, no elongate spines in the first dorsal fin, 9–10 dorsal and 9 anal fin rays, pectoral fin rays 17–18 of which 7–11 are branched, and an unbranched fifth pelvic fin ray.

Description. Dorsal fins VI + I 9 –10 (mean = 9.6), second or third spine longest but not elongate, reaching posteriorly to between bases of sixth spine of D1 and spine of D2 when adpressed, first ray of second dorsal fin unbranched (branched in 3 specimens), posterior element of last dorsal ray unbranched, last ray reaching posteriorly 50– 67 –72% (mean = 65.8%) of distance between its base and first dorsal procurrent caudal ray; anal fin I 9 (once 10), first ray unbranched as is posterior element of last ray, which reaches posteriorly 45– 62 –65% (mean = 57.4%) distance between its base and first ventral procurrent caudal ray; pectoral fin 17 –18 (mean = 17.2), 3– 4 – 6 (mean = 4.1) dorsal and 2– 5 (mean = 4.1) ventral unbranched rays separated by 7– 8 –12 (mean = 9.1) branched rays, fin reaching posteriorly to a point above area between anus to urogenital papilla; pelvic fin I 5, first four rays with one sequential branch, fifth ray unbranched ( Fig. 3 ) and 52–67% the length of fourth (mean = 57.0, fourth ray damaged in holotype), fourth ray reaching posteriorly to a point between posterior margin of urogenital papilla and base of second anal ray; no fraenum; basal membrane varies from absent, where membrane from fifth ray joins to abdomen lateral to midline to 9% length of fourth ray ( Fig. 3 , red arrow). Lateral scales 23– 24 (mean = 23.4), where 24 count due to additional small anteriormost scale; anterior transverse scales 8– 9 –10 (mean = 8.9; yellow arrow in Fig. 3 shows direction of count); posterior transverse scales 7– 8 (mean = 7.9; blue arrow in Fig. 3 shows direction of count); no scales on median predorsal, cheek or opercle; scales extending anteriorly on sides of body from upper pectoral base curving up to middle of first dorsal fin, a few specimens with 1–2 small isolated cycloid scales on side of nape; pectoral-fin base usually with 3 vertical rows of scales, with 1– 2, 2– 4 and 3– 5 scales per row respectively; scales in midline anterior to pelvic fin 4– 5 (mean = 4.5), where 4, usually an additional scale anteriorly just lateral to midline; scales on pectoral-fin base, breast, anterior midline of belly cycloid ( Fig. 3 , green arrows show anteriormost ctenoid scales), scales on sides of nape and rest of body ctenoid; 12 circumpeduncular scales, 7– 8 (mean = 7.2) scales between base of last anal fin ray and first ventral procurrent caudal ray. Upper jaw teeth with an outer row of 6–8 evenly spaced, curved, enlarged canines decreasing in size posteriorly and extending to bend of premaxilla, short inner row of straight conical teeth slightly larger than teeth anterior to them, 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 enlarged, slightly curved teeth about one-third length of outer row, decreasing in size posteriorly, ending at beginning of coronoid process, 2–3 irregular rows of small conical teeth between these, grading posteriorly to single row and ending near anterodorsal tip of coronoid process of dentary. Tongue broadly rounded, sometimes with small central tip. Gill opening extending anteroventrally to below mid- to posterior third of pupil; outer gill rakers on first gill arch 3– 4 (mean = 3.3) + 12– 13 –14 (mean = 13.1), total rakers 15– 17 (mean = 16.4). Anterior naris a short tube extending half way over upper lip, posterior naris a pore with raised rim, separated from eye by 1.5 –2 times its diameter, nasal apparatus occupying anterior two-thirds of snout ( Fig. 4 ). Bony interorbital width 30– 33 –43% (mean = 36.6) of pupil diameter in width, interorbital with moderately developed ‘U’-shaped trough about as wide as deep, a shallow postorbital groove but not trench-like. Cephalic sensory papillae as in Figure 4 , number of papillae in each row given in Table 1 . Ridge of tissue (or dermal crest) may extend anterior to first dorsal spine for up to two-thirds distance to interorbital. Epaxialis extending anteriorly to above a vertical with posterior margin of pupil. Abdominal/caudal vertebral transition not examined, but presumed to be Type B.

Colour pattern, live, based on images of holotype, 18.2 mm SL female, ROM 94889, Mapia Atoll, Fig. 5 A, and paratype, Ayau Besar Atoll, ROM 98809, Fig. 5 B. Holotype bicoloured, dark red dorsally and white ventrally below midlateral line continuing anteriorly across cheek just below eye. Midline of dorsum with diffuse white stripe from above posterior margin of pupil to anteriormost dorsal procurrent caudal fin ray. Iris dark gold above pupil, red margined purple stripe across top of pupil which continues anteriorly on snout as diffuse, and much wider, red stripe. White stripe margined dorsally with red across bottom of pupil, continuing anteriorly to maxilla and, after short disjunction behind eye, posteriorly across top of opercle, where white grades to blue margined dorsally with red. Area of snout between stripes and above dorsal stripe yellow, anterior snout and lips red. Rays of dorsal, pectoral and upper half of caudal fins light red (pelvic and anal fin not visible), ventral half of caudal lighter. Upper pectoral fin base with white spot more intense than surroundings. Internal lighter stripe (spinal cord?) anteriorly, followed by three internal lighter spots beneath dorsal fins. Specimen from Ayau Besar Atoll essentially similar, but upper body more orange than red, lower half of body very pale pink, anterior half of lower eye stripe blue rather than white, and spot at upper pectoral fin base more obvious and bluish-white. In other live specimens, dorsum reddish-orange (possibly juveniles). Freshly collected specimen from Pulau Mof (ROM 87934, Fig. 5 C) with yellow head grading to orange on nape and then to orange-red behind this with light greenish-yellow cheek, pale pinkish white abdomen and posterior body, blue or white of iris stripes dark purple, dorsal fins with basal, half-pupil diameter wide basal white stripe bordered dorsally by yellow stripe half this width, then hyaline, caudal fin with outer edges whitish and central rays dirty orange-brown.

Preserved colour. Background pale straw yellow, with heavy concentrations of dark brown chromatophores on dorsal half of nape and body, decreasing in number ventrally, where absent from about two scale rows from ventral midline. Moderate number of similar chromatophores on cheek with some on dorsal part of opercle, and on upper and lower lips. Stripes across iris evident as lines of dark brown chromatophores ( Fig. 6 ) which continue anterodorsally onto snout. Lower line continues posterodorsally as dark ovoid patch over dorsal tip of preopercle and from anterodorsal process of opercle half way to its posterodorsal tip; in some specimens dark line continuous from snout to opercle. Fins hyaline except for scattered brown pigment cells on distal half of second dorsal fin, some in caudal fin, and along distal margin of last few anal fin rays.

Etymology. Named in honor of Abraham Aturiri, Governor of West Papua province from 2006-2016, in recognition of his energetic efforts to ensure the conservation and wise, sustainable use of the hugely diverse coral reefs of the Bird's Head Seascape for the benefit of the Papuan people. The species has been informally referred to as Trimma RW sp 99.

Distribution. Currently known with certainty only from the northern oceanic atolls of West Papua province, Indonesia ( Fig. 18 ).

Comparisons. Trimma aturirii is unique among species in the genus in its bipartite colour pattern (red or orange above, white or pale pink below). The two oblique dark stripes on either side of the pupil (blue-edged with red margins in life, dark brown in preservative), the lower of which continues after a short hiatus posteriorly along the dorsal margin of the opercle, are shared only with an undescribed species (T. RW sp 49) from the Line Islands, which lie some 7,500 kilometers due east of the easternmost sample from Indonesia. Specimens from the latter locality invariably have 10 (vs. 9) anal rays, and the red colouration of the body extends ventrally almost to the ventral midline (vs. confined above midlateral septum). Ten other described species of Trimma share with the new species the lack of scales in the predorsal midline and an unbranched fifth pelvic fin ray. Of these, T. anaima Winterbottom, 2000 , has 8 dorsal and anal fin rays, unbranched pectoral fin rays, and less than 15 total gill rakers (vs. 9–10, 9, middle rays branched and 15 or more gill rakers). Trimma grammistes ( Tomiyama, 1936) has unbranched pectoral fin rays and a second dorsal spine that reaches posteriorly beyond the first element of the second dorsal fin when adpressed (vs. branched, and not reaching beyond spine). That species also has a pupildiameter wide black stripe from the upper lip through the eye and along the body above the midlateral line until it curves gradually to the center of the caudal peduncle and onto the caudal fin (vs. stripe absent). Three other species, T. bisella Winterbottom, 2000 , T. cana Winterbottom, 2004 , and T. sostra Winterbottom, 2004 , have greatly elongate second dorsal spines (vs. not elongate) and lack a dermal crest anterior to the first dorsal fin (vs. present). The former species has four red bars on the head and white saddles on the peduncle (vs. both absent), while the latter two have a pale body with seven broad red bars or blotches (vs. bars absent). Trimma sanguinellus Winterbottom & Southcott, 2007 has an entirely red body, unbranched pectoral fin rays, and a second dorsal spine that extends posteriorly beyond the first element of the second dorsal fin when adpressed (vs. bicoloured, branched, and second spine anterior first spine of second dorsal fin respectively). Trimma maiandros Hoese et al., 2011 , has a pale grey body with large yellow blotches, 5 or fewer branched pectoral rays, and no opercular stripe (vs. bicoloured, <5 branched pectoral rays, and dark opercular stripe respectively). Trimma stobbsi Winterbottom, 2001 has a yellow to brown body with scale pockets outlined and a dark, half pupil diameter sized, roughly ovoid spot on the upper margin of the opercle near its posterior margin (vs. bicoloured with stripe along dorsal margin of opercle). Trimma hotsarihiensis Winterbottom, 2009 , has a yellow body with scale margins more strongly marked, yellow spots in the caudal fin and dark basal stripes in the dorsal and anal fins. It has a dark diffuse stripe across the top of the opercle, but the stripe is horizontal and ends anteriorly at the level of the mid-pupil rather than being obliquely oriented downwards to pass below the eye. Trimma kudoi Suzuki & Senou, 2008 , has a similar overall colouration as T. hotsarihiensis , but lacks the dark stripe over the opercle. It has two oblique purple-blue stripes, one at the dorsal margin of the iris and a second that passes across the middle of the pupil (vs. two stripes on either side of the pupil).

Discussion. Specimens of this species were usually found perched individually on vertical surfaces at the back of crevices and overhangs in depths ranging between 38– 70 m. Despite extensive sampling of these depths on reefs throughout eastern Indonesia, this species has only been found on exposed outer reef slopes of the northernmost oceanic atolls and islands of West Papua (Mapia Atoll, Ayau Besar Atoll and Pulau Mof).

An analysis of the CO1 gene of the three tissue specimens of this species suggests that they are phenetically closest to T. hotsarihiensis , from which they are separated by a minimum of 9.9% of the base pairs.

Figures

FIGURE 1. Trimma aturirii, 16.2 F, ROM 98809, lateral (A) and dorsal (B) views of head papillae. Note paths of sensory nerves (narrow purple lines linking papillae); specimen somewhat distorted by a fully splayed hyoid arch. Specimen stained with cyanine blue. Photos by R. Winterbottom.

FIGURE 3. Trimma aturirii, 15.3 mm SL female, ROM 95269, ventral view of region between pelvic and anal fins. Red arrow indicates basal membrane; green arrows show anterior extent of ctenoid scales on belly; yellow and blue arrows show direction for anterior and posterior transverse scale counts respectively. Specimen stained with cyanine blue. Photo by R. Winterbottom.

FIGURE 4. Trimma aturirii, 16.2 mm SL male, ROM 95269, lateral (A) and dorsal (B) views of head papillae. Red arrows show supernumerary papillae, thin white lines indicate lines of papillae. Specimen stained with cyanine blue. Photos by R. Winterbottom.

FIGURE 5. Trimma aturirii, left lateral views of live specimens from Mapia Atoll, ROM 94889, holotype (A—image reversed); Ayau Besar Atoll, ROM 98853 (B—image reversed); and a freshly collected specimen from Mof Island, ROM 87934 (C). Photos by M. V. Erdmann.

FIGURE 6. Trimma aturirii, 14.0 mm SL female, ROM 87934, Mof Island, Raja Ampat, lateral view of head (unstained). Photo by R. Winterbottom.

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.

Tables

TABLE 1. Counts of cephalic sensory papillae in the different rows of the three new species of Trimma. Data given as minimum to maximum values, with the mean, Standard Deviation and number of specimens for which data were available respectively given in parentheses, except where the value was invariant, where only the number of specimens is given. Terminology follows that used in Winterbottom (2011) as emended here.

Papillae row	T. aturirii	T. kardium	T. trioculatum
Row a	6 (17)	6 (4)	6 (11)
Row b	5–7 (5.9, 0.484, 16)	5–7 (5.8, 0.839, 4)	6–8 (6.3, 0.617, 11)
Row c	5 (16)	5 (4)	5 (11)
Row cp	1 (16)	1 (4)	1 (11)
Row d	4–6 (5.5, 0.707, 16)	6–7 (6.5, 0.500, 4)	5–8 (6.4, 0.979, 11)
Row d'	5–7 (5.8, 0.634, 16)	6–7 (6.5, 0.500, 4)	6–9 (7.0, 0.853, 11)
Row e –ant.	10–13 (11.1, 0.872, 17)	11–13 (11.5, 0.866, 4)	11–14 (12.5, 0.782, 11)
Row e –post.	10–14 (11.3, 1.250, 16)	12–13 (12.3, 0.433, 4)	12–15 (13.1, 0.966, 11)
Row i – ant.	7–8 (7.5, 0.499, 17)	7–8 (7.8, 0.433, 4)	6–8 (7.2, 0.833, 11)
Row i – post.	6–8 (7.4, 0.704, 16)	7–8 (7.5, 0.500, 4)	6–8, 7.2, 0.575, 11)
Row p	6 (17)	6 (4)	6–7 (6.1, 0.287, 11)
Row r	2 (17)	2 (4)	1–2 (1.9, 0.287, 11)
Row f	2–4 (2.9, 0.428, 16)	3 (4)	2–3 (2.9, 0.287, 11)
Row cs"	3 (17)	3 (4)	3 (11)
Row g	6–8 (7.2, 0.716, 11)	4–6 (5.0, 0,707, 4)	4–6 (5.0, 0.577, 6)
Row n	1 (5)	1 (1)	1-3 (2)
Row x	5–6 (5.5, 0.500, 16)	6–7 (6.5, 0.500, 4)	7–8 (7.6, 0.484, 8)
Row u	4–5 (4.8, 0.433, 4)	5 (1)	5 (1)
Row z	4–6 (4.5, 0.612, 16)	5–6 (5.3, 0.433, 4)	5–6 (5.4, 0.490, 10)
Row ot	10–13 (11.1, 1.053, 16)	9-13 (11.8, 1.639,6)	12–16 (13.5, 1.076, 11)
Row os	4–6 (4.8, 0.6534, 15)	4 (2)	4–7 (6.1, 0.875, 9)
Row oi	3–4 (3.8, 0.390, 16)	4 (4)	3–5 (3.9, 0.539, 10)