Apogonichthyoides umbratilis, Fraser, Thomas H. & Allen, Gerald R., 2010

Fraser, Thomas H. & Allen, Gerald R., 2010, Cardinalfish of the genus Apogonichthyoides Smith, 1949 (Apogonidae) with a description of a new species from the West-Pacific region, Zootaxa 2348, pp. 40-56 : 45-49

Apogonichthyoides umbratilis new species

Figures 2–4; Table 1–2

Type material examined: Apogonichthyoides umbratilis Holotype NMV A14250 (1, 32.7), Australia, Western Australia, Northwest Shelf, between Port Hedland and Dampier, 19°39'S 116°22'E, RV Soela, 7 Jun 1983, 46m. Paratypes: BPBM 40973, (1, 32), Palau, Koror, Ngeruketabel I., off E side, RW 04-13, 25 May 2004, 24– 26 m, R. Winterbottom et al. CAS 227497 (1, 32.6), Palau, Koror, Ngeruketabel I., off E side, RW 04-13, 25 May 2004, 24– 26 m, R. Winterbottom et al. ROM 77131 (4, 32.6–41.4), Palau, Koror, Ngeruketabel I., off E side, RW 04-13, 25 May 2004, 24– 26 m, R. Winterbottom et al. USNM 395059 (1, 35), Palau, Koror, Ngeruketabel I., off E side, RW 04-13, 25 May 2004, 24– 26 m, R. Winterbottom et al. WA M P.22914.006, (2, 27.0–27.2), Indonesia, Raja Ampat Islands, Fam Islands, Melissa’s Garden Reef, 0°35'S 130°19'E, 23 Aug 2007, M. Erdmann. WAM P.32791.001, (2, 9.5–19.1), Indonesia, West Papua, Pulau Karawatu, 04°02'S 133°28'E, 20 Apr 2006, 0–10 m, G. R. Allen. WAM P.330134-001, (2, 17–27), Brunei, Abana Patch NW, 5°07'N 115°04'E, 24 Oct 2008, 20– 21 m, M. V. Erdman, one cleared and stained.

FIGURE 2. Apogonichthyoides umbratilis new species, paratypes. A. Live, Brunei, WAM P.330334-001, 27.3 mm SL, G. R. Allen. B. Live, West Papua, WAM P.32791-001, 27.2 mm SL, G. R. Allen. C. Post mortem, Palau, ROM 77131, 36.3 mm SL, ripe female, R. Winterbottom. D. Holotype, NMV A14250, 32.7 mm SL, Western Australia, in ethyl alcohol. Apogonichthyoides timorensis . E. Live, Nusa Penida (near Bali), Indonesia, by G. R. Allen. F. Preserved in ethyl alcohol, AMS I.17099-014, 54 mm SL, Trobriand Islands Papua New Guinea. Apogonichthyoides opercularis . G. Postmortem, Darwin, Northern Territory, Australia, by J. E. Randall. H. Preserved in ethyl alcohol, WAM P. 31204-042, 47 mm SL, Kingfisher Island, Western Australia.

Diagnosis: Blackish spot in first-dorsal fin; five brownish bars on body and caudal peduncle; broad faint cheek mark; high postocular darkish spot; pectoral-fin rays 14 with tiny to small darkish spot above axil. Description: Range of proportions (as percentage of standard length) in Table 1 with holotype first and paratypes in parentheses.

Dorsal fin VII(I)-I,9, third and fourth spines thickened; anal fin II,8; pectoral-fin rays 14-14; pelvic fin I,5; longest procurrent caudal rays segmented, 1+8-7+1 principal caudal rays; pored lateral-line scales 24; transverse scale rows above lateral line 2, one large, one small; transverse scale rows below lateral line 6; median predorsal scales 3; circumpeduncular scale rows 12 as 5+2+5; total gill rakers and rudiments 14–16, well developed 8–9, upper arch 3+1, lower arch 7-8+3-5; second arch with small tooth patches or low rudiments.

Villiform teeth in several rows on the premaxilla and on the dentary; 1–2 rows on vomer; one row on the palatine; none on ectopterygoid, endopterygoid or basihyal.

Vertebrae 10+14. Interhamal gap with 1+4 ( Table 2 ). Five free hypurals; one pair of slender uroneurals; three epurals; a free parhypural. Three thin supraneurals, two supernumerary spines on first dorsal pterygiophore. No procumbent spines (spurs). Basisphenoid present. Supramaxilla absent. Posttemporal serrate on posterior margin. Preopercle serrate on vertical edge, fewer serrations with crenulate horizontal edge, ridge smooth. Infraorbitals smooth. Infraorbital shelf present on third bone. Eighth dorsal spine a hidden nubbin, distal radial free. A pair of rounded scleral bones.

Scales ctenoid on cheek, subopercle, opercle, isthmus, base of pectoral fin, ctenoid behind pectoral fin and on body, nape and predorsal scales cycloid. Two large scales, cycloid (smaller fish) or becoming ctenoid (larger fish) on base of pelvic fin, no axillary scale. Pored lateral-line scales complete, fourth scale with two pores above and one below main canal (fig. 3); last pored lateral-line scale simple (fig. 3).

Head with many small pores (fig. 4). Anterior end of supra-orbital canal as a broad slit pore at edge of snout with a cleft-like distal edge open, one large pore over eye; lachrymal with large anterior pore near flat posterior nare opening, two large ventral slit pores along edge of lachrymal; anterior portion of dentary with dentary (anterior) and mental (ventral) pores, posterior with a large articular pore; supratemporal canal with posterior canals onto nape and predorsal scales.

Anterior nare tubular, posterior nare flat.

Caudal fin emarginate; second dorsal and anal fin with rounded distal edges.

Life colors: See Figure 2A & B. Brownish marks on head and body; no snout stripes; blackish spot in first-dorsal fin; brownish broad cheek mark from eye to ventral arm of preopercle; three brownish marks behind and above eye; brownish bar from base of first-dorsal fin on to side of abdomen behind pectoral fin; faint brownish bar below lateral line to near origin of anal fin; brownish bar from base of second-dorsal fin to base of anal fin; two faint bars on caudal peduncle followed by a brownish basicaudal bar; first-dorsal fin with blackish spot near distal portion of fin between third and fifth spines, whitish to pale regions around spot; second-dorsal fin with faint stripe-like darker area, otherwise with whitish small spots and darkish small spot at posterior base on fin; caudal fin with pale membranes and small brownish marks on the fin rays; anal fin with some whitish and brownish markings without any stripe-like appearance; pelvic fin with brownish broad mid-bar, whitish distally and proximally; pectoral fin pale; iris brownish.

Preserved color pattern: See Figure 2C & D. Holotype with a broad darkish cheek mark, three short darkish post-ocular marks, small darkish posttemporal mark, no snout stripes; lips and gular area uniform; body with six variably darkish bars, anterior bar from origin of first three dorsal spines extending behind pectoral fine onto side of abdomen, second bar fainter on side from below pored lateral-line scales, third bar from below posterior portion of second-dorsal fin to mid-anal fin, three bars on caudal peduncle; first-dorsal fin with darkish area between spines 3–5, anteriorly pale below darkish area, last two spine membranes dusky to base; darkish stripe in lower third of second-dorsal fin; no stripe in anal fin but with some spotting; pelvic fin with darkish markings; pectoral fin pale, small dark spot above axil; caudal fin with tiny melanophores on rays, membranes pale; peritoneum, intestine and stomach pale.

Paratypes similar to holotype, several without visible second bar, several without faint caudal peduncle bars, one without small spot above axil of pectoral fin.

Etymology: The Latin word umbratilis meaning of the shade, retired or private, in reference to the observed cryptic behavior.

Distribution: Known from Western Australia, Raja Ampat Islands of West Papua, Indonesia, Brunei, and Palau. Most of the specimens were from water depths greater than 20 meters.

Remarks: Apogonichthyoides umbratilis is a comparatively smaller species than its relatives. Our largest specimen was 41 mm SL. This species will likely be found throughout the West Pacific region based on the collection localities reported here. Specimens have been confused with Apogonichthyoides timorensis and with species of Foa . Lower pectoral fin-ray counts, markings on the head and multiple bars on the body distinguish Apogonichthyoides umbratilis from A. timorensis .

Regan (1908) described Apogon gardineri based on one specimen from Cargados Carajos (St. Brandon’s Shoal) from 55 meters. He suggested a relationship with Nectamia bandanensis . Our study suggests that Regan’s species belongs in Apogonichthyoides and is most similar to A. umbratilis . Apogonichthyoides gardineri , a rare deep water species with two bars on the body, one broad peduncle bar and 14 pectoral-fin rays, is endemic to the Mascarene Plateau including Mauritius ( Fraser, 2000).

Bleeker (1851) described Apogon cantoris and subsequently illustrated this species in his Atlas (1871–76: fig 1, perc. 32). Bleeker’s specimens of Apogon cantoris are much larger than Apogonichthyoides umbratilis . See remarks under Apogonichthyoides timorensis for other differences.

Head pore pattern differs from Ostorhinchus fleurieu Lacépède, 1802 , by having only one large supraorbital pore, many more small pores on the snout and interorbit, no large mandibular pores, more mandibular pores and size of the terminal lachrymal pore (see Bergman, 2004).

A serrate preopercle and completely pored lateral-line scales will separate Apogonichthyoides umbratilis from look-alike Foa species with a smooth preopercle and incomplete pored lateral-line scales.

The new species is generally found solitary or in pairs at depths ranging from about 10 to 40 meters. It displays cryptic behavior, at least during daylight hours, sheltering between rocks and rubble. The species has not been observed free swimming, but only when flushed from its lair with the use of clove-oil or rotenone. Specimens collected at the Raja Ampat Islands, West Papua were living in a rubble field in sheltered waters at the base of a small islet. Brunei fish were found under rock slabs on a submerged patch reef (several km from shore) with abundant sponges and gorgonians and minimal hard corals. Specimens collected at Palau were from a flat sand and shell bottom with abundant Gonipora, some Fungia and considerable macroalgae. The ROM collection had three ripe females and one buccal male without eggs.

Tables

TABLE 1. Proportions as a percent of standard length for Apogonichthyoides umbratilis, A. timorensis and A. opercularis. The proportions for primary types are followed by parentheses for all other types and additional material.

Body Proportions	umbratilis ‡	timorensis †	opercularis *
percent of standard length	N=12	N=26	N=18
greatest body depth	37.3(39.0–42.1)	36.3(34.4–39.3)	42.6(37.3–44.9)
head length	42.8(41.6–46.7)	39.3(39.8–43.3)	40.9(36.0–43.6)
eye diameter	13.5(14.0–16.2)	13.6(12.0–14.8)	11.9(10.7–13.5)
snout length	11.3(9.8–11.5)	10.7(8.9–10.5)	9.7(9.4–10.6)
bony interorbital width	8.9(9.2–11.5)	8.2(7.1–10.4)	8.1(6.9–8.8)
upper jaw length	21.1(20.9–23.0)	17.8(17.6–20.2)	17.3(15..0–18.8)
caudal-peduncle depth	16.2(15.1–17.1)	13.8(13.8–17.6)	17.4(14.6–17.9)
caudal-peduncle length	24.6(21.0–25.2)	21.0(21.9–27.0)	22.8(17.6–24.3)
1st dorsal-fin spine length	3.4(2.5–4.5)	3.9(2.6–5.0)	3.5(2.7–4.4)
2nd dorsal-fin spine length	11.0(8.0–12.0)	9.2(8.0–12.7)	9.4(7.6–11.3)
3rd dorsal-fin spine length	19.9(18.2–22.0)	23.8(19.4–25.1)	20.6(19.3–23.6)
4th dorsal-fin spine length	18.6(16.6–21.5)	21.0(17.9–23.5)	17.7(17.5–20.5)
2nd dorsal-fin spine	14.4(14.8–17.7)	17.8(15.4–18.7)	17.3(15.5–18.4)
1st anal-fin spine length	3.1(3.3–5.2)	3.0(1.7–4.9)	2.6(2.0–4.2)
2nd anal-fin spine length	12.8(12.7–14.1)	15.1(12.6–15.6)	16.4(13.9–17.5)
pectoral-fin length	24.8(22.2–29.4)	20.4(20.7–25.8)	24.8(20.3–26.1)
pelvic-fin length	24.2(23.1–26.2)	25.8(24.3–30.9)	25.2(22.3–26.3)

‡ Apogonichthyoides umbratilis , holotype, paratypes. † Apogon timorensis , holotype, no paratypes; including holotype of Apogonichthys darnleyensis and holotype and paratypes of Apogonichthyoides fraxineus . * Apogon opercularis lectotype, paralectotypes.