Eustomias deofamiliaris Gibbs, Clarke & Gomon 1983

Eustomias deofamiliaris

DIAGNOSIS.—Two terminal bulbs separated by a very long distance (3.6% SL, 2.4 times length of distal bulb). Barbel 66% SL. Proximal bulb not centered in stem, extending externally and bearing 3 slender filaments, the longest reaching end of distal bulb. Distal bulb 1.5% SL, 1.5 times proximal-bulb length, with an intermediate (∼11% SL) terminal filament bearing a short side branch. Axis of stem between bulbs and in filament densely pigmented. External chevron-shaped or rounded striated areas unpigmented except near base of stem. Middorsal paired spots between occiput and dorsal-fin origin 8.

DESCRIPTION OF HOLOTYPE.—Maturing male, 108.8 mm SL. D 26. A 38. P1 3. P2 7. IP 8, PV 30. VAV 19. OV 31. VAL 19. AC 18. IA 57. IC 75. OA 50. OC 68. VAV photophores over anal-fin base 8. Branchiostegal photophores 12. Premaxillary teeth 14 on both sides: from anterior to posterior, a long fixed tooth followed by a long space, a fixed fang and replacement followed by a long space, a short fixed and a long depressible tooth, a short and a moderate depressible tooth (2 short fixed teeth right), a short and 2 moderate depressible teeth, and 5 short depressible teeth. Maxilla with about 25 short, slanting, serra-like teeth. Mandibular teeth 18 left, 20 right: from anterior to posterior, a short fixed symphysial tooth followed by a moderate space, a fixed fang and a short depressible tooth (replacement?) followed by a long space, a long and a short depressible tooth, a moderate fixed tooth, a short depressible tooth, a long depressible tooth, 2 short fixed and 1 moderate depressible tooth (a short-to-long series of 2 fixed and 2 depressible teeth right), 4 short depressible teeth (a short-to-moderate series right), and 3 very short depressible teeth (4 right). Vertebrae 68, the 1st only partially ossified.

Measurements (in mm): Predorsal length 92.0, preanal length 76.5 prepelvic length 62.1, head length 16.3, barbel length 71.8, proximal-bulb length 1.1, distal-bulb length 1.6, distance between bulbs 3.9, filament broken after being drawn and before being measured (estimated 12), snout length 6.0, fleshy orbit length 3.8, postorbital-organ length 1.0, lower-jaw length 12.7, upper-jaw length 11.7, depth behind head (greatest depth) 7.3, caudal-peduncle depth 1.7, pectoral fin broken, pelvic-fin length 15.0, dorsal-base length 15.5, anal-base length 30.1, longest premaxillary tooth 2.0, longest mandibular tooth 1.5.

Axis of stem, between bulbs, and terminal filament densely pigmented. External chevron-shaped or roundish areas and internal mounds on axis unpigmented except close to base of stem. No bulblets seen in terminal filament. Tiny bulblets in proximal filaments, which are unpigmented. Diameter of stem between bulbs much wider than proximal to bulbs.

Proximal bulb oblate-spheroidal, located to side of stem axis and forming a bulge; 3 slender, unpigmented filaments at its lateral tip. Distal bulb ovoid, strongly narrowed proximally, with a slender filament that has a single short branch at about one-third of its length.

SIMILAR SPECIES.—No other species of Nominostomias with 2 terminal bulbs has an eccentric proximal bulb or filaments on that bulb. The density of stem and teminal-filament pigmentation is reminiscent of inconstans, and the barbel length and distal-bulb length are consistent with that species, but a proximal bulb, when present in inconstans, is contiguous with the distal bulb, is centered in the stem, and lacks filaments.

DISTRIBUTION.—The holotype and only known specimen is from off Oahu, Hawaiian Islands (Figure 40).

ETYMOLOGY.—From the Latin deo (dative of deus, god) plus the adjective familiaris (knowing intimately), in allusion to the fact that we mortals are uncertain whether this specimen represents a valid species or a wildly different anomalous condition of some other species.

MATERIAL EXAMINED (1 male).—Holotype: USNM 223764 (, 108.8), 21°20′–30′N, 158°20′–30′W, 0–70 m, 0038–0250, 25 Sep 1973. The specimen has its skin largely intact but free from the body, and most internal organs are missing, except for portions attached to the anterior and posterior ends.

GROUP II

The species of this group have 2 terminal bulbs and a single terminal filament that has 2 to many prominent side branches ranging in length from about half the central-filament length to longer than the central filament. The filament and its branches have bulblets along part or all of their length, the bulblets ranging in size from very small to wider than the diameter of the containing filament or branch and sometimes causing external swellings. Five species comprise this group. A synopsis of their salient characters is given in Table 3, and their barbel and postorbital-organ dimensions are plotted in Figures 14–17.