Ostorhinchus aphanes, Fraser, Thomas H., 2012

Fraser, Thomas H., 2012, A new species of deeper dwelling West Pacific cardinalfish (Percomorpha: Apogonidae) with a redescription of Ostorhinchus atrogaster, Zootaxa 3492, pp. 77-84 : 77-83

Ostorhinchus aphanes n.sp.

Figure 1 A & B, Table 1

Material examined. Ostorhinchus aphanes holotype, ROM 81239, 44.6mm SL, Palau, Off Uchelbeluu Reef (short drop-off), 07°16'24.8"N 134°01'26.6"E, RW 06–14, 73m, 28 Mar 2006, P. Colin. Paratypes, ROM 91948, (4, 39–41), same data as holotype. Paratype, ROM 1839cs, (1, 41), same data as holotype, cleared and counter stained. Comparative material. Apogon dispar holotype BPBM 9378, (1, 44.1), Palau Islands, Augulpelu Reef, 13 Apr 1970. Apogon cladophilos holotype WAM P.31480.001, (1, 30.0), Australia, Queensland, Lizard Island, 10 Dec 1982. Apogon franssedai paratypes WAM P.30511.001, (2, 50–51), Indonesia, Pasir Sari Reef, 20– 25 m. Apogon gularis holotype USNM 225672, (1, 36.1), Yemen, Red Sea, 14°55'N 42°28'E, 13 Jun 1958. Apogon leptofasciatus paratypes, WAM P.31782.001, (2, 48–49), Indonesia, Raja Ampat Is., Wruwarez I., 30 Mar 2001, 15 m. Apogon lineomaculatus paratypes WAM P.30514.002, (2, 46–49), Indonesia, Bali, 20 May 1992 20– 25 m. Apogon melanoproctus holotype BPBM 15747, (1, 40.0), Solomon Islands, Florida Island, 30 July 1973. Apogon ocellicaudus holotype WAM P.29049.025, (1, 48.8), Australia, Western Australia, Ashmore Reef, East Pass, 15 Sep 1986, 20– 25m. Apogon oxygrammus paratypes WAM P.31780.001, (2, 31–34), Indonesia, Raja Ampat Is., Pef I., 4 Nov 2001, 43m.

Diagnosis. Pale fins, a single faint yellow stripe above the pored lateral line scales, teeth in one row at front of premaxilla to two rows on side then a single row, teeth on dentary in 1–2 rows becoming larger on side in a single row, basicaudal spot with discrete melanophores.

Description. For general body shape see Fig. 1 . Proportions as percent of standard length, paratypes in parentheses: greatest body depth 31.2 (30.4–32.2); head length 36.5 (37.8–40.2); eye diameter 12.3 (11.2–11.8); snout length 8.5 (9.3–10.2); bony interorbital width 7.8 (7.8–8.4); upper-jaw length 15.9 (16.1–17.2); caudalpeduncle depth 13.2 (12.5–14.6); caudal-peduncle length 27.6 (27.0–29.2); first dorsal-fin spine length 2.7 (1.5–3.0); second dorsal-fin spine length 10.8 (10.8–11.8); third dorsal-fin spine length 15.0 (14.9–15.2); fourth dorsal-fin spine length 15.0 (13.5–14.4); spine in second dorsal fin 11.9 (10.5–12.1); first anal-fin spine length 2.2 (3.0–2.8); second anal-fin spine length 11.4 (11.0–11.8); pectoral-fin length 23.3 (22.8–23.3); pelvic-fin length 19.7 (19.7–20.6).

Dorsal fin VIII as VII(0)-I,9, two supernumerary spines on first pterygiophore, no hidden eighth spine; anal fin II,8, one supernumerary spine on first pterygiophore, second spine in series with first pterygiophore, first anal ray branched; pectoral fin 15–15 (two with 14–14; three with 15–15); pelvic fin I,5; principal caudal rays 9+8, branched caudal rays 8+7, 9 upper procurrent rays with cartilage plates under first 6 rays, 9 lower procurrent rays with cartilage plates under first 3 rays and rays 5–8, ray 4 supported by haemal spine from 22nd vertebra.

Pored lateral line scales 24, about 4 small elongate pored scales extend onto caudal fin; transverse scale rows above lateral line 2; transverse scale rows below lateral line 6; median predorsal scales 5; circumpeduncular scale rows 12 as 5 +2+5. Scales with a single row of ctenii on nape, cheek, preopercle, subopercle, opercle, breast and rest of body, small ctenoid axillary scale, anterior pelvic scale narrow ctenoid, posterior cycloid (three with anterior ctenoid scale, two with anterior cycloid scale, one with posterior ctenoid scale), small cycloid scales on base of caudal fin. Lateral-line scales with one pore above and one pore below main canal.

Upper arch with 2 rudiments and 3 rakers, lower arch with 14 rakers and 1 rudiment as 2+3-14+1, 17 rakers, 20 total (0-2+ 3-13-15 +0-1, 16–18 rakers, 17–21 total); no gill rakers on second arch.

Villiform teeth in one row with a short gap at symphysis of premaxilla, becoming two rows with inner row smaller than outer row, tapering to a single row near distal end; two rows of villiform teeth on dentary at symphysis tapering to one row and increasing in size distally; one row of villiform teeth on vomer, larger near outer edge; one row on palatine; none on ectopterygoid, endopterygoid or basihyal.

Vertebrae 10+14; 7 epineurals beginning on first vertebra; 8 ribs beginning on third vertebra, all rod-shaped except last short and flattened; five free hypurals, urostylar centrum with a sheath over anterior ends of third and fourth hypurals; one pair of long slender uroneurals, upturned anteriorly, extending from mid-urostyle to half of fifth hypural; three epurals, first hooked and proximally expanded slightly, second with slightly expanded proximal tip, third as a rod; a free parhypural; three supraneurals, as 0/0/0 with respect to first three neural spines, free distal radial on seventh pterygiophore lacking serial spine; anal fin pterygiophores relationship with first haemal spine 1/ 4, anterior flange on first anal ptergyiophore with a point.

Basisphenoid present; supramaxilla absent; posttemporal serrate on posterior margin; preopercle ridge with a few small serrations near angle, preopercle edges serrate on vertical and horizontal margins; six infraorbital, edges smooth, with narrow, elongate shelf length of third infraorbital; 7 branchiostegals, 3 ventrally on epihyal, 2 on face of ceratohyal, 2 on face of epihyal; urohyal with anterior process.

Eyes with two ossified sclerals and partial ring of scleral cartilages on either side.

Anal and genital openings well anterior of anal-fin origin; peritoneum with melanophore spots, becoming larger posteriorly toward the openings. Stomach and intestine blackish.

Anterior naris with raised rim as short tube grading higher from front to back, posterior naris flat as vertical oval. Terminal supraorbital pore not reaching edge of snout, lachrymal with two anterior pores on ventral edge, anterior dentary pores on face and ventral side.

Pore patterns on head incomplete: anterior supraorbital pore slightly posteriad edge of upper lip, many small pores on interorbit, no large dorsal pores along edge of eye, small pores on post orbit and anterior nape, pores along surface of preopercle, narrow slit at anterior of lachrymal below nares, two large pores near anteroventral edge of lachrymal, row of small pores near ventral edge of mid to posterior lachrymal, many tiny pores along lower and posterior edge of eye, two rows, outer and inner along dentary, 4–5 medium sized inner pores anterior to articular pore

Free neuromast patterns not well-preserved, on upper branched principal caudal rays at least seven rows of free neuromasts along ventral side of rays 9–15 and on lower unbranched and branched principal caudal rays seven row on dorsal side of rays 1–7; free neuromasts on snout, interorbit, post orbit, anterior nape, preopercle, infraorbitals, cheek, dentary; no free neuromasts were detected on surfaces of lateral line scales, except the last one or two terminal scales on caudal fin.

Post mortem color pattern. ( Fig. 1 A). From a post-mortem slide by Richard Winterbottom: tip of lower jaw black with melanophores along dentary and upper jaw, scattered within a yellowish snout mark, some yellowish along edge of upper jaw; yellowish stripe from over eye and above lateral line extending under second dorsal fin; interrupted yellowish post-ocular markings on infraorbital, dorsal arm of preopercle and on opercle suggestive of the continuation of the snout mark, scattered yellowish cast below eye and on opercular series; a narrow mid-line body linear series of yellowish, reddish and blackish chromatophores/melanophores with more dispersed tiny spots forming the limits of the stripe-like feature ending just prior to a basicaudal mark; roundish basicaudal mark a mixture of reddish-brown chromatophores and melanophores covering most of the last vertebrae, hypurals and onto a few of the basal caudal fin-rays; body translucent; peritoneum silvery with band of melanophore spots along lower side of abdomen, fewer melanophore spots along upper side; blackish area above peritoneum extending back and down to near origin of anal fin; all fins without markings, pale with reddish cast on second dorsal, caudal, anal and pelvic fin-rays.

Color in alcohol. ( Fig. 1 B). Anterior snout and jaws with melanophores, postocular line of melanophores reaching nearly to basicaudal spot about size of pupil, line of melanophores from snout over eye, just above posttemporal and lateral line ending under first dorsal; nape and predorsal scales outlined with melanophores, rest of body and fins without any markings, roof of mouth pale, melanophores on inner side opercle and preopercle

Distribution. Known only from Palau, but expected elsewhere in the West Pacific region.

Etymology. aphanes , a Greek adjective meaning obscure and referring to the difficulty identifying this species without carefully examining premaxillary and dentary teeth.

Remarks. Three paratypes are ripe females and one paratype exhibited buccal expansion without eggs. These specimens were collected during a deep dive by Pat Colin along a steep wall in 73 m. It is unlikely that collections will be common at such depths. Differences and similarities with the new species and other apogonids usually taken from deep dives follows: all have VII-I,9 dorsal fin (see Table 1), II,8 anal fin, serrated lower preopercle edge, three supraneurals and 12 circumpeduncular scales unless noted as different (below and Table 1) and all are placed in Ostorhinchus until this heterogeneous, catch-basket genus is examined in greater detail for monophyly, see Mabuchi et al., (2006).

Ostorhinchus cladophilos ( Allen and Randall, 2002) differs by having a single brown stripe from snout though eye, along midline, tapering to midline black basicaudal spot, with nine soft anal rays, 14 pectoral fin rays, 20–22 (4-5+16-17) developed gill rakers and four predorsal scales. Ostorhinchus dispar ( Fraser and Randall, 1976) differs in having a narrow red band from the tip of the snout to the base of the caudal fin ending in a squarish red spot, two red spots behind and above the eye, broadly red-tipped caudal fin lobes, 13–14 pectoral fin rays, 21-25 (4-5+17-20) developed gill rakers, 4–5 predorsal scales and two supraneurals. Ostorhinchus franssedai ( Allen, Kuiter and Randall, 1994) differs by having two narrow red brown stripes, one on snout over eye above lateral line scales fading out before the second dorsal fin, the second as a stripe on the side of the snout continuing behind eye along midline to a large black basicaudal spot, with 14 pectoral fin rays, 17-18 (3-4+14-15) developed gill rakers and five predorsal scales. Ostorhinchus gularis ( Fraser and Lachner, 1984) differs by having six first dorsal spines and an anal opening just behind the pelvic fins. Ostorhinchus leptofasciatus ( Allen, 2001) differs by having two thin brown stripes, one from snout, over eye and above the pored lateral line scales onto caudal peduncle, the second from side of snout then behind eye along midline to caudal peduncle near basicaudal bar with expanded midsection as a black spot, with 14 pectoral fin rays, 18 (4+14) developed gill rakers and 5–6 predorsal scales. Ostorhinchus lineomaculatus ( Allen and Randall, 2002) differs by having a brown stripe on snout through eye along midline of body to near black mid line basicaudal spot, about nine faint darkish bars on side of abdomen and above anal fin from just below midline stripe, 15 pectoral fin rays, 23-25 (5+18-20) developed gill rakers and four predorsal scales. Ostorhinchus melanproctus ( Fraser and Randall, 1976) differs in having a faint brown-orange caudal base with a white spot above, a white spot behind the base of the second dorsal fin, a black area around the anus, 14 pectoral fin rays, 22-24 (4-5+18-19) developed gill rakers, five predorsal scales and two supraneurals. Ostorhinchus ocellicaudus ( Allen, Kuiter and Randall, 1994) differs by having a broad dark brownish stripe on snout through eye fading out on the opercle, brownish stripe from lower lip to edge of eye, a large ocellated basicaudal black spot with 14 pectoral fin rays, 17-18 (3+14-15) developed gill rakers, four predorsal scales, and 11 circumpeduncular scales Ostorhinchus oxygrammus ( Allen, 2001) differs by having a single broad stripe from edge of the eye reaching to the tip of the caudal fin, with 13 pectoral fin rays, 14 (2+12) developed gill rakers and 3–4 predorsal scales.

Among the slender, deeper-water species and brief characters given above, only Ostorhinchus franssedai is nearly identical in color pattern and meristics. Ostorhinchus aphanes has pale fins, versus yellowish first dorsal and pelvic fin, a single faint yellow stripe above the pored lateral line scales versus two red-brown stripes; teeth in one row at front of premaxilla to two rows on side then a single row versus two rows at front then a band of five to six rows; teeth on dentary in 1–2 rows becoming larger on side versus 2–3 rows to a single row on side; basicaudal spot discrete melanophores versus continuous black.

Redescription and Status of Amia atrogaster

Smith and Radcliffe in Radcliffe (1912) described Amia atrogaster from eight specimens. Fraser and Lachner (1984) briefly discussed the type series with reference to the number of first dorsal spines and gill raker counts. It is appropriate to review the characters of this species in light of the number of deeper-water, slender-bodied apogonids placed in Apogon sensu lato ( Fraser and Randall, 1976; Allen, Kuiter and Randall, 1994; Allen, 2001; Allen and Randall, 2002). This species has not been reliably reported since the original description.

Ostorhinchus atrogaster (Smith & Radcliffe in Radcliffe, 1912) Figures 2 A–C, Table 1

Material examined. Amia atrogaster Holotype: USNM 70249; 46.8 mm SL; Philippines, Luzon I., Manila Bay to Lingayen Gulf, 16°30'36"N 120°11'06"E; Albatross D 5442; 10–11 May 1909; 82 m; digital of film x-ray. Paratypes: USNM 163227; (7, 35–48); same data as holotype; digital of film x-ray. Ostorhinchus atrogaster ? WAM P.28306-001; (3, 44–56); Australia, Western Australia; 3 Dec 1979.

Description of holotype. For general body shape see Fig. 2 A&B. Proportions (as percent of standard length): greatest body depth 29.0; head length 41.0; eye diameter 10.5; snout length 10.2; bony interorbital width 17.9; upper- jaw length 16.0; caudal-peduncle depth 11.5; caudal-peduncle length 25.2; second dorsal spine length 14.5; first anal-fin spine length 2.3; second anal-fin spine length 9.4; pectoral-fin length 17.9; pelvic-fin length 16.6.

Dorsal fin VII-I,9, two supernumerary spines on first pterygiophore, first spine missing in holotype ( Fig. 2 C); anal fin II,8, one supernumerary spine on first pterygiophore, second spine in serial association with first pterygiophore, following ray branched; pectoral fin-rays 15, broken on right side; pelvic fin I,5; principal caudal rays 9+8, branched caudal rays 8+7; upper gill arch with 3 rudiments and 5 developed gill rakers, lower gill arch without rudiments and 19 developed gill rakers.

No scales present.

Villiform teeth in several rows on the premaxilla; one row on the dentary; one row on the palatine and vomer; none on ectopterygoid, endopterygoid or basihyal.

Vertebrae 10+14; hypurals 3 and 4 partially fused, hypurals 1, 2 and 5 free; one pair of slender uroneurals; three epurals; a free parhypural; three supraneurals as 0/0/0/ in association with anterior neural spines, none procumbent.

Supramaxilla absent; posttemporal serrate on posterior margin; preopercle ridge smooth, edges serrate on posterior vertical and ventral horizontal margins; infraorbital edge smooth.

Color in alcohol. None remains on body or fins. Tip of lower jaw dark with melanophores, scattered melanophores on snout. Smith and Radcliffe described the color patterns as: Ground color cream-buff; traces of a slightly decurved, silvery-white band from scapula to base of caudal; tip of chin and snout to middle of eye dusky black; dusky points on head; iris silvery; tip of spinous dorsal, blackish; caudal dusky distally; other fins hyalin; peritoneum silvery white; stomach jet black.

Life & post mortem colors. Unknown.

Distribution. Known from the types and one putative collection in western Australia.

Remarks. The holotype was damaged during capture in a beam trawl. Smith and Radcliffe in Radcliffe (1912) provided a figure of the holotype. This figure may be considered somewhat hypothetical for there are no scales present on the holotype, the first dorsal spine is missing, the second dorsal spine is complete with the third, fourth spines along with the spine in the second dorsal fin all broken. All caudal fin-rays are broken. The largest paratype, 47.5 mm SL has hypurals 1+2 fused and 3+4 fused, has VII first dorsal spines, 3 supraneurals and 2+5-19+1 rudiments and gill rakers for a total of 24 developed rakers and 27 combined elements. This specimen is conspecific with the holotype. Two paratypes (39.5 mm SL with eggs in mouth, with damaged first dorsal fins and 41.0 mm SL (both missing the first spine?) have 2+5-18+1 and 2+5-17+0 rudiments and gill rakers on the gill arch. Both of these specimens have all of the hypurals free without any sign of fusion. One paratype (42.4 mm SL) with damaged first dorsal fin (missing the first spine?) also was missing the left gill arch. One paratype (35.5 mm SL) has VII first dorsal spines but the first gill arch counts are 2+3-13+2 and is a different species, possibly the new species described here or a small Ostorhinchus apogonides as suggested by Fraser and Lachner (1984). Finally, two paratypes sustained more damage than listed above and no worthwhile information could be obtained. All of the paratypes with free hypurals also had three supraneurals.

Table 1. A comparison of selected characters of some deeper-water species of Ostorhinchus . Data from Allen (2001), Allen and Randall (2002), Allen, Kuiter and Randall (1994), Fraser and Lachner (1984), Fraser and Randall (1976), Smith and Radcliffe in Radcliffe (1912) and this paper.

Apogon atrogaster is treated as valid. There was not enough material to determine if the hypurals tend to fuse with size. The smaller paratypes that may be missing the first dorsal spine, with slightly lower gill arch counts and free hypurals, have an unresolved relationship with the holotype and largest paratype. Smooth condition of the preopercular ridge, infraorbitals and posttemporal should be viewed with caution because these edges may have been serrated but abraded in the trawl to appear smooth. This species was reported from Western Australia ( Paxton et al., 1989) based on three specimens at the Western Australian Museum without location or depth data. Radiographs of these fish were inconclusive on the status of the caudal skeleton and supraneurals.

Figures

FIGURE 1. Holotype of Ostorhinchus aphanes, ROM 81239, 44.6 mm SL, Palau. A. Post mortem, by R. Winterbottom. B. Preserved in ethyl alcohol, by T. Fraser.

FIGURE 2. The holotype of Amia atrogaster, USNM 70249, 46.8 mm SL, Philippines, Luzon I., Manila Bay to Lingayen Gulf. A. Modified figure 3 from plate 35, Smith & Radcliffe in Radcliffe, 1912 drawn by V. Dandridge. B. Preserved holotype, by T. Fraser. C. Positive image of the holotype from scanned negative radiograph by S. Raredon, inset of enlarged caudal complex.