Eustomias suluensis Gibbs, Clarke & Gomon 1983

Two terminal bulbs separated by a long interspace, 1.9-2.4 times the length of distal bulb. Barbel length mostly 52-59% SL. Three long filaments, arising together from distal end of distal bulb or from a short stem; with numerous very small bulblets along most of their length. Distal bulb 1.5-1.8 times length of proximal-bulb. Barbel pigment variable, but a prominent dark spot or cap formed at the base of distal bulb. Middorsal paired spots between occiput and dorsal-fin origin 9 (Ref. 11333).

Dorsal soft rays (total): 24; Analsoft rays: 39; Vertebrae: 67

Eustomias suluensis

DIAGNOSIS.—Two terminal bulbs separated by a long distance (2.4%–2.8% SL, 1.9–2.4 times length of distal bulb). Barbel length 52%–59% SL. Three long filaments (15%–20% SL) arising together from distal end of distal bulb or from a short stem, with numerous very small bulblets along most of their length. Distal bulb 1.2%–1.3% SL, 1.5–1.8 times length of proximal bulb. Barbel pigment variable, but a prominent dark spot or cap formed at base of distal bulb. Middorsal paired spots between occiput and dorsal-fin origin 9 (smaller specimen).

DESCRIPTION.—Based on only 2 specimens (109 and 138 mm SL), so suggestions of growth patterns uncertain.

Barbel length is 50% SL in the smaller specimen, 59% in the larger. The smaller specimen has faded very much everywhere, and the only discernible barbel pigment is a suggestion of a spot at the base of the distal bulb. In the larger specimen, the axis of the stem, between the bulbs and in all filaments, is darkly pigmented; the pigmented stem axis is continuous around the outside of the proximal bulb, forming a stripe on that bulb; at the distal end of the axis between the bulbs, the pigment is very dark, forming a wide black cap over the base of the distal bulb; the external chevron-shaped or roundish striated areas on the stem are unpigmented in the proximal one-fifth of the stem, pigmented in the next two-fifths, and unpigmented in the distal two-fifths until pigmented just before the proximal bulb.

The proximal and distal bulbs are both ovoid in shape, the distal larger in all dimensions. The proximal bulb is 0.7% SL in the smaller specimen, 0.8% in the larger. The distal bulb is 1.3% SL in the smaller specimen, 1.2% in the larger. The distal bulb is 1.5–1.8 times the length of the proximal bulb.

The distance between bulbs is 2.4% SL in the smaller specimen, 2.8% in the larger. This distance is 1.9–2.4 times the length of the distal bulb and 3.3–3.5 times the proximal bulb.

The filaments are 15% SL in the smaller specimen, 20% in the larger. The filaments have bulblets rather closely spaced for almost their entire length; these bulblets are very small proximally, becoming tiny distally, and in the large specimen they are conspicuous against the pigmented axis.

The only male (109 mm) has a very small postorbital organ, 0.5% SL, 24% of fleshy orbit. Apparently, enlargement of this organ begins at a relatively large size.

No barbel colors have been recorded.

DESCRIPTION OF HOLOTYPE.—Female, 138.3 mm. D 24. A 39. P1 3. P2 7. IP 7. PV 33. VAV 16. OV 32. VAL 18. AC 19. IA 56. IC 75. OA 50. OC 69. VAV photophores over anal-fin base 6. Branchiostegal photophores 12. Premaxillary teeth 13 on both sides: from anterior to posterior, a long fixed tooth followed by a long space, a fixed fang, 2 short fixed teeth, a long depressible tooth, a short-to-moderate series of 2 fixed and 2 depressible teeth, and 4 short depressible teeth. Maxilla with about 20 short, slanting, serra-like teeth. Mandibular teeth 21 left, 20 right: from anterior to posterior, a short fixed symphysial tooth followed by a moderate space, a fixed fang (with replacement), 2 long depressible teeth, 2 short fixed teeth, 2 long depressible teeth, a short fixed tooth, 2 long depressible teeth, (a 3rd forming right), a short-to-moderate series of 5 depressible teeth (the 5th forming on right), and 5 short depressible teeth, the last one forming (4, the last one forming right). Vertebrae 67.

Measurements (in mm): Predorsal length 115.1, preanal length 96.3, prepelvic length 77.6, head length 18.9, barbel length 81.5, proximal-bulb length 1.1, distal-bulb length 1.6, distance between bulbs 3.9, filament length 27.2, snout damaged, fleshy orbit length 3.6, postorbital-organ length 0.9, lower-jaw length 15.8, upper-jaw length 14.6, depth behind head (greatest depth) 9.6, caudal-peduncle least depth 1.9, pectoral fins damaged, pelvic-fin length 18.2, dorsal-base length 17.9, anal-base length 35.5, longest premaxillary tooth 2.2, longest mandibular tooth 1.6.

Proximal and distal bulbs both ovoid, the proximal somewhat flattened on side away from pigmented axis. Barbel pigmentation and filament bulblets described above.

SIMILAR SPECIES.—The other 3 species with multiple long filaments have either 2 (kreffti) or 4 (posti, bertelseni), and all of these have prominent large bulblets and/or inclusions in 1 or more of the filaments, whereas suluensis has 3 filaments containing only very small bulblets.

Eustomias crossotus bears some resemblance to suluensis, but in crossotus all branches arise from a single terminal filament, albeit fairly close to the distal bulb, and the bulbs are much closer together (the interspace usually shorter than the distal bulb).

DISTRIBUTION.—Both known specimens were taken in the eastern part of the Sulu Sea, off the Philippine Islands (Figure 42).

ETYMOLOGY.—An adjective combining Sulu (the Southeast Asian Sea) plus the Latin suffix -ensis (denoting locality of occurrence), alluding to the habitat of the only known specimens in the Sulu Sea.

MATERIAL EXAMINED (1 male, 1 female).—Holotype: USNM 223714 (, 138.3), 09°22′N, 122°06′E, 0–110 m, 2307–2358, 5 Jun 1975.

Paratype: ZMUC P202847. (, 109.1), 07°23′N, 121°29′E, 0–300 m (600 mw) 0245, 30 Jun 1929.