Siphamia goreni, Gon & Allen, 2012

Gon, Ofer & Allen, Gerald R., 2012, 3294, Zootaxa 3294, pp. 1-84 : 45-48

Siphamia goreni new species

Figures 20b, 22; Table 9

Holotype: TAU P.11353, 16.4 mm, male, Eritrea, Dahlak Archipelago , Dahlak Kebir, ship wreck, 11 m, M. Goren, 28 May 1995.

Paratypes: AMS I.45900-001 (originally SMF 34707), 16.9 mm, male, Red Sea coast of Saudi Arabia, Farasan Archipelago, Katir Island, 16º48.46998’N, 41º43.749’E, reef slope, 10 m , T. Alpermann and J. Bouwmeester, 8 November 2010 ; BPBM 41098 (originally SMF 33581) , 16.7 mm, male, Red Sea coast of Saudi Arabia, Amaq, 18°22.948'N, 41°26.965'E, fringing reef, 6–7 m, S . V. Bogorodsky, 31 March 2011 ; SAIAB 96710 , 2 : 16.6–18.7 mm and TAU P.13902, 2: 16.1– 16.1 mm, both originally TAU P.11353, collected with holotype ; SAIAB 185719 , 2 : 19.0– 20.5 mm, females (originally SMF 33582 and 33579, respectively), collected with BPBM 41098 ; USNM 405349 (originally SMF 33580) , 18.3 mm, female, collected with BPBM 41098 ; WAM 33627-001 (originally SMF 34709) , 15.2 mm, female, collected with AMS I.45900-001; SMF 33586 , 20.5 mm, SMF 33587 , 19.8 mm, and SMF 33613 , 19.65 mm, all females, Red Sea coast of Saudi Arabia, Farasan Archipelago, Gomah Island, 16°36.811'N, 42°1.081'E, coral patch on sandy slope, 7 m, S . V. Bogorodsky, 3 April 2011 ; SMF 34708 , 16.9 mm, male, as well as SMF 33648, SMF 34710 and SMF 34711, 18.6 , 11.7 and 12.5 mm, respectively, all females, collected with AMS I.45900-001.

Diagnosis: Dorsal rays VII+I,9; anal rays II,8; pectoral rays 13–14 (rarely 15); tubed lateral-line scales 2–3; median predorsal scales apparently missing in all specimens; total gill rakers 2–3 + 9–12; developed gill rakers 1 + 8–9; gill rakers on ceratobranchial 7 (rarely 6). Body depth 2.4–2.9 in SL and body width 1.8–2.2 in the depth; eye diameter 2.5–3.2 in head length; first dorsal spine 2.4–3.0 in second spine; second dorsal spine 3.8–4.5, spine of second dorsal fin 3.9–5.2, and second anal spine 5.4–6.9, all in head length; pectoral-fin length 4.4–5.1 and pelvic-fin length 4.4–4.8 in SL; caudal-peduncle length 1.3–2.2 in distance between pelvic spine insertion and anal-fin origin. Preopercular edge with 17–25 small serrations along its posterior and ventral edge, largest serrations at angle; preopercular ridge smooth. Tip of light organ on each side of tongue bound by membrane.

Colour in life: unknown.

Colour when fresh (from photograph by S. Bogorodsky): pale brown with variable amount of dark dots of various sizes, becoming darker ventrally; head with orange hue, more enhanced behind upper part of eye and along preopercle ridge and some orange dots scattered mostly ventrally; eye encircled by narrow ring of orange dots of variable size; branchiostegal rays with dark dots; spines of first dorsal and pelvic fins with dark marks interspersed with small orange dots; second dorsal, anal and caudal fins as well as soft portion of pelvic fin with orange-brown dots mostly along margins of rays; light organ silvery with dark vertical striations; dorsal margin of light organ dark brown.

Colour in alcohol: variable; body pale to dark brown with variable amount of blackish dots of various sizes; head usually paler than body and peppered with dark dots, denser dorsally; dark dots along middle of caudal peduncle usually present, sometimes extending to front of body, becoming gradually smaller. Dark dots extending posteriorly from occiput as 2–3 series along upper part of body, usually fading below second dorsal fin; second dorsal and anal fins usually with small dark dot at base of each fin ray and larger dot between adjacent pterygiophores; first dorsal-fin spines with dark dots, but membrane between them largely pale; pectoral fin with dark dots; pelvic-fin base usually darker then body; pelvic spine and innermost 1–2 rays with dark dots; other fins pale; dark mark on cheek from ventral edge of eye to angle of preopercular ridge sometimes present; two or three dark dots across caudal-fin base; premaxilla with series of small dark dots or dark brown line; throat and branchiostegal rays with small dark dots; palate with dark dots anteriorly; peritoneum dark brown with variable amount of dark dots; intestine and stomach pale with dark dots of various sizes; light organ along ventral margin of body and caudal peduncle with dark striations.

Smallest specimen, TAU P.13902, 16.1 mm, from Eritrea and largest specimen examined, 20.5 mm, from Saudi Arabia.

Description: Proportional measurements of the holotype and selected paratypes are given in Table 9. Dorsal rays VII+I,9; anal rays II,8; last soft ray of dorsal and anal fins branched to base; pectoral rays 14 (13–15), two upper and 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 8 (7–8); tubed lateral-line scales 2 (2–3); most body scales missing in many specimens; median predorsal scales seem to be missing in all; developed gill rakers 1 + 8 (on paratype with 1 + 9); gill rakers on ceratobranchial 7 (6–7); branchiostegal rays 7.

Body deep and compressed, its depth 2.6 (2.4–2.9) in SL and its width 1.95 (1.8–2.2) in depth; head length 2.05 (1.95–2.3) in SL; snout length 5.3 (4.35–6.0), eye diameter 2.6 (2.5–3.2), and interorbital space, slightly convex, 4.7 (4.1–4.9), 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 1.8 (1.7–1.9) and lower jaw 1.6 (1.5–1.7) in head length; both jaws with band of small, conical teeth; upper jaw band with 1–2 series at symphysis, increasing to about 3–4 series at middle of jaw; lower jaw band with 3–4 series at symphysis tapering to 2 series posteriorly; inner series teeth of both jaws somewhat enlarged; vomer with 1–2 sometimes irregular series of small conical teeth; palatines with similar teeth arranged in single irregular series anteriorly, widening to 2 series posteriorly (1 series in one paratype and 2 series in another).

Rear nostril on front edge of eye at level of upper half of pupil, its vertical diameter about 3 times in pupil diameter; anterior nostril round and of similar size, at level of middle of eye and at about mid-distance between tip of snout and rear nostril.

Preopercular edge with 17 (15–25) small serrations, largest around angle; preopercular ridge smooth; exposed edge of posttemporal smooth (2–4 minute serrations in paratypes).

Body scales large, very thin and easily shed, mostly missing in many specimens; remaining scales cycloid to weakly spinoid.

Dorsal-fin origin slightly behind vertical through upper pectoral-fin base; first dorsal spine broken (2.4–3.0 in second spine); second dorsal spine broken (3.8–4.5) and third dorsal spine longest 3.0 (2.5–3.15) in head length; spine of second dorsal fin 4.4 (3.9–5.2) and longest dorsal soft ray 2.2 (2.1–2.7) in head length; first anal spine 2.0 (1.6–2.8) in second spine, and second anal spine 6.7 (5.4–6.9) and longest anal ray 2.8 (2.2–3.0) in head length; pectoral fin length 4.7 (4.4–5.1) in SL; pelvic fin origin on vertical with posterior preopercular edge (slightly behind in one paratype); pelvic fin length 4.3 (4.4–4.7) in SL and pelvic spine length 1.5 (1.4–1.65) in fin’s length; caudal fin emarginate, 3.4 (3.5–3.9) in SL.

Dorsal profile of head straight to slightly convex, predorsal distance 2.2 (2.05–2.5), preanal distance 1.5 (1.3–1.5), and prepelvic distance 2.5 (2.2–2.8) in SL; caudal peduncle depth 1.8 (1.5–2.1) in its length, and the length 1.4 (1.3–2.2) in distance between pelvic-fin base and anal-fin origin; latter distance 3.5 (2.3–3.2) in SL.

Colour in alcohol: head and body pale brown with dark brown to blackish dots of various sizes; dots on anterior part of body dense, gradually becoming fewer and dispersed posteriorly; larger blackish dots in one series along middle of caudal peduncle becoming smaller anteriorly; dark dots on cheek forming triangular mark, widest at lower edge of eye, tapering toward angle of preopercle ridge; premaxilla with small dark spots near symphysis and narrow dark brown line posteriorly; faint dark line from anterior end of cheek mark to anterior end of preopercular ridge; palate, branchiostegal rays, fins, peritoneum, intestine and stomach as described in Diagnosis above.

Remarks: See Tables 1–3 for frequency distributions of pectoral rays, lateral-line scales and gill rakers. The lateral-line scales had 0–3 spines and some scales on predorsal area had 2–4 spines on their posterior edge. One paratype (SMF 33648) had eight soft rays in the second dorsal fin.

Siphamia goreni is a member of the S. tubifer species group. Within this group it shares a low lateral-line scales count with S. majimai and S. jebbi ( Table 2). It is easily distinguished from S. majimai which has six spines in the first dorsal fin. S. jebbi differs from S. goreni in having two developed gill rakers and a higher total number of developed gill rakers ( Table 3), as well as in its different colour pattern with much fewer and smaller dark dots on the body and much more orange pigment ( Fig. 20c–e). Furthermore, S. majimai and S. jebbi are not known from the western Indian Ocean. In the absence of lateral line scales S. goreni may be confused with S. arabica , S. mossambica and S. tubifer all of which have a similar colour pattern and occur in the northern part of the western Indian Ocean. However, the latter three species usually have 15 pectoral-fin rays ( Table 1). In addition, S. arabica has fewer developed gill rakers ( Table 3) and, with S. tubifer , more serrations (23–35) on the preopercular edge while S. mossambica has fewer such serrations (3–19).

Siphamia goreni is known only from the southern Red Sea where it was collected in the Dahlak and Farasan Archipelagos, as well as in Amaq, Saudi Arabia ( Fig. 6). It was found sheltering among the spines of sea urchins living in patches of coral reef at 6– 11 m.

Etymology: This species is named goreni for Dr. Menachem Goren of Tel-Aviv University, Israel, who collected the first specimens of this species, in recognition of his contribution to our knowledge of Red Sea fishes.