Siphamia spinicola, Gon & Allen, 2012

Gon, Ofer & Allen, Gerald R., 2012, 3294, Zootaxa 3294, pp. 1-84 : 66-69

Siphamia spinicola new species

Figures 28e, 31; Table 12

Holotype: BPBM 27105 , 24.4 mm, male, New Caledonia, NE coast, Kinde Reef , 10–15 m, rotenone, P. Laboute and J.-L. Menou, 10 January 1979.

Paratypes: CAS 84288, 2 : 14.8–24.1 mm, juvenile and female, respectively, Vanuatu, Espiritu Santo , Palikulo Bay, isolated coral head , R. L. Bolin and A. Persson, 7 October 1958 ; SAIAB 1934 , 6 : 15.2–27.4 mm, Vanuatu, Efate, Port Vila Harbour, E side of Iririki Island , 17º44’96”S, 168º18’22”E, 1 m , R.U. Gooding, 23 December 1969 ; USNM 133997 , 2 : 26.1–32.5 mm, Indonesia, Biak, Schouton Islands , F.M. Bayer, April 1945 ; USNM 133998 , 26.7 mm, collected with USNM 133997 ; USNM 205089 , 16.5 mm, Federated States of Micronesia, Yap, Woleai Atoll, in lagoon opposite Utagal Island , in association with Acanthaster planci, L.R. McCloski , 28 July 1969 ; USNM 357887 , 3 : 14.7–21.8 mm, Papua New Guinea, N end of New Ireland, 2º35’21”S, 150º47’18”E, among spines of Diadema savignyi , on rock and coral , R.U. Gooding, 18 September 1969 ; USNM 357888 , 25.8 mm, Papua New Guinea, Milne Bay, Basilaki Island, N point, coral reef, 0–10 m , T. Roberts, 22–25 August 1975 ; USNM 357889 , 4 : 24.9–29.6 mm, collected together with USNM 357888 ; BMNH 2009.11 .27.4, 17.4 mm and MNHN 2009-1671 , 16.6 mm, both originally from USNM 357887 ; AMS I.45073-001, 26.7 mm and NSMT-P 96742 , 29.2 mm, both originally from USNM 357889 .

Other material: BPBM 33847 , 22.5 mm, Chesterfield Island , beam trawl , R / V Alis , 22 August 1988 ; BPBM 36233 , 23.7 mm, Papua New Guinea, D’Entrecasteaux Islands , Normanby Island, hand net, 35 m, with fire urchin, J.L. Earle, 12 December 1993 ; USNM 324812 , 14.3 mm, Loyalty Islands , Uvea Island, S end of lagoon, 20º42’48”S, 166º24’00”E, small patch reef surrounded by sand, 13 m, rotenone, J . T. Williams et al., 13 November 1991 ; USNM 219946 , 3 : 28.9–30.0 mm, Vanuatu, Espiritu Santo, A. Power .

Diagnosis: Dorsal rays VII+I,9; anal rays II,8; pectoral rays 14–16; tubed lateral-line scales 14–21; median predorsal scales 4–5; total gill rakers 2–4 + 9–11 = 12–14; developed gill rakers 1 + 8–9; gill rakers on ceratobranchial 7–8. Body depth 2.4–2.7 in SL and body width 1.8–2.2 in the depth; eye diameter 2.8–3.4 in head length; first dorsal spine 2.5–3.25 in second spine; second dorsal spine 4.15–5.5, spine of second dorsal fin 3.5–4.6, and second anal spine 5.5–6.1, all in head length; pectoral-fin length 4.4–5.4 and pelvic-fin length 4.1–5.3 in SL; caudal-peduncle length 1.3–1.9 in distance between pelvic spine insertion and anal-fin origin. Preopercular edge with 19–32 small serrations; preopercular ridge smooth. Tip of light organ on each side of tongue bound by membrane.

Colour in life: unknown, but see colour description of fresh holotype below.

Colour in alcohol: body brown to dark brown with a variable amount of darker dots of various sizes; pale areas between areas of dense dots sometimes present giving the impression of three faint dark stripes; a line of dark dots sometimes present along ventral edge and lower posterior edge of preopercular ridge; proximal part of spines of first dorsal (at least anteriorly) and pelvic fins with small dark dots; other fins pale, but caudal-fin base sometimes brown; scattered dark dots may be present on upper limb of first gill arch; peritoneum with dark dots of various sizes; intestine and stomach with minute dark dots.

Smallest specimen, 14.3 mm, USNM 324812, from Loyalty Islands and largest specimen examined, 32.5 mm, USNM 133997, from Biak, Indonesia.

Description: Proportional measurements of the holotype and selected paratypes are given in Table 12. Dorsal rays VII+I,9; anal rays II,8; last soft ray of dorsal and anal fins branched to base; pectoral rays 15 (14–16), two upper and two lowermost rays unbranched; pelvic rays I,5, all soft rays branched; principal caudal rays 17, upper and lowermost rays unbranched; upper and lower procurrent caudal rays 7–6 (6–7 on each side in paratypes); tubed lateral-line scales 18 (14–21); vertical scale rows 23 (23–24); horizontal scale rows at level of second dorsal fin origin 7; median predorsal scales 4 or 5; circumpeduncular scales 12; developed gill rakers 1 + 9 (1 + 8–9); gill rakers on ceratobranchial 8 (7–8); branchiostegal rays 7.

length.

Body deep and compressed, its depth 2.6 (2.4–2.7) in SL and its width 2.2 (1.8–2.2) in depth; head length 2.0 (2.0–2.2) in SL; snout length 5.5 (4.2–6.7), eye diameter 3.4 (2.8–3.15, and slightly convex interorbital space 4.9 (4.7–4.9), all in head length.

Mouth terminal, oblique and large; maxilla reaching posteriorly to vertical at about mid-distance between rear edges of pupil and eye respectively; upper jaw length 2.0 (1.9–2.0) and lower jaw 1.7 (1.6–1.8) in head length; both jaws with band of small, conical teeth; upper jaw band with 1–2 series at symphysis, increasing to about 5–6 series at middle of jaw; lower jaw band with 3–4 series at symphysis tapering to one series posteriorly; inner series teeth of both jaws somewhat enlarged; vomer with a single series of small conical teeth; palatines with similar teeth arranged in single, irregular series.

Rear nostril close in front of eye and above level of middle of eye, its vertical diameter about 5 times in pupil diameter; anterior nostril slightly larger, with raised fleshy rim, at level of middle of eye and closer to upper lip than to rear nostril.

Preopercular edge with 32 (19–26) serrations, largest around angle; preopercular ridge smooth; exposed edge of posttemporal with 4 small serrations (smooth to 3).

Body scales large, thin and easily shed; scales weakly spinoid or without spines; tubed lateral-line scales of some paratypes with vertical line of minute papillae along middle of scale above and below tube; caudal fin with low scaly sheath of 2–3 scale series across its base; other fins without scales or scaly sheath.

Dorsal-fin origin over posterior margin of second lateral-line scale and slightly behind vertical through pelvicfin base; first dorsal spine broken, (2.5–3.25 in second spine); second dorsal spine broken (4.15–5.5) and third dorsal spine, longest, 2.8 (2.5–2.9) in head length; spine of second dorsal fin broken (3.9–4.6) and longest dorsal soft ray 2.2 (2.1–2.3) in head length; first anal spine 1.95–3.3 in second spine in paratypes (see Table 12 for the proportion of this spine as percentage SL in holotype); second anal spine and longest anal ray broken in holotype, but are 5.5–6.1 and 2.5–2.8 in head length, respectively, in paratypes; pectoral fin reaching posteriorly to above anal-fin origin (slightly in front of it in some paratypes), its length 4.65 (4.4–5.4) in SL; pelvic fin length 5.3 (4.1–4.6) in SL and pelvic spine length 1.3 (1.4–1.6) in fin’s length; caudal fin emarginate, 3.3 (3.2–3.6) in SL.

Dorsal profile of head straight; predorsal distance 2.2 (2.05–2.3), preanal distance 1.5 (1.4–15) and prepelvic distance 2.3 (2.1–2.5) in SL; caudal peduncle depth 1.7 (1.5–1.8) in its length, and the length 1.35 (1.3–1.9) in distance between pelvic-fin base and anal-fin origin; latter distance 3.6 (3.0–3.9) in SL.

Colour when fresh (from colour slide by J.E. Randall): body pale brown with dark brown dots of various sizes overlaid with scattered smaller orange-brown dots. Dark dots denser above lateral line and on predorsal area giving back dark appearance; dark dots below lateral line in more or less distinct series separated by pale areas peppered with minute dark dots; top of snout, lower jaw, throat and end of caudal peduncle paler with fewer, contracted dark dots; branchiostegal rays with dark dots; pupil ringed with orange-brown pigment ( Fig. 28e); all fins peppered with small orange-brown dots; first dorsal fin spines also with dark dots on lower part; margin of pupil ringed in orange; light organ silvery with dark brown vertical striations.

Colour in alcohol: body brown with dense dark brown dots of various sizes, snout paler; melanophores of cheek expanded and indistinct; top of head with larger and more widely spaced dark dots; narrow pale area with few dark dots across caudal peduncle in front of caudal-fin base; branchiostegal rays with dark dots; fins pale except for few dark dots in proximal part of first dorsal-fin spines; pelvic-fin base dark brown; narrow dark line from below ventral edge of eye, under maxilla, to anterior end of preopercular ridge; roof of mouth with dark dots behind vomer and between palatines; peritoneum with dense dark dots of various sizes; intestine and stomach with smaller dark dots.

Remarks: See Tables 1–3 for frequency distributions of pectoral rays, lateral-line scales and gill rakers. Of 19 specimens in which median predorsal scales could be counted with confidence 16 fish had four scales, and four fish had five scales. However, only two scales were present in the holotype. Two specimens (USNM 357889) had two series of teeth on the middle section of the palatines. Several specimens had a vertical line of papillae at least on some lateral-line scales (RUSI 1934; USNM 357888 and 357889). These papillae appeared to be missing on the holotype. In a number of specimens the tubed scales of the lateral line were followed posteriorly by 1–3 scales with vestigial tubes. In one specimen (SAIAB 1934) the lateral line had a non-tubed scale between fully tubed scales in two places. The holotype, a male, had a large genital papilla (about 75% of the length of the first anal-fin spine) and this feature was also shared by three paratypes (USNM 219946).

Siphamia spinicola is similar to S. fuscolineata , S. tubifer and S. fraseri . The latter two species also have partially overlapping geographical distributions ( Figs. 6, 8, respectively). In S. fraseri there are fewer tubed lateralline scales, and in S. fuscolineata and S. tubifer this character is modally lower and higher, respectively ( Table 2). In addition, the number of developed gill rakers is modally lower in S. tubifer and higher in S. fraseri ( Table 3). Another partially sympatric species, S. jebbi , is easily distinguished in having a pale body with inconspicuous dark dots, much shorter tubed lateral line, fewer pectoral-fin rays and modally more gill rakers, including two developed rakers on the upper limb of the first gill arch ( Tables 1–3).

This species is known from Biak in eastern Indonesia, Papua New Guinea, Woleai Atoll of the Federated States of Micronesia, Vanuatu, New Caledonia and the Chesterfield Islands ( Fig. 8). Specimens of this species were collected from and observed among the spines of Acanthaster planci in Woleai Atoll (USNM 205089) and Diadema savignyi in New Ireland (USNM 357887) on bottoms of coral and rock or on coral patches surrounded by sand.

Etymology: This species is named spinicola (Latin: “spine-dweller”) with reference to its habit of living among the spines of echinoderms.