View data on Catolog of Fishes here.
View data on Catolog of Fishes here.
Barbel length increases from 22% SL in the smallest specimen (48 mm) to 60%–85% in those longer than 100 mm. All specimens have black pigment in the axis of the stem and between the bulbs, and specimens larger than 80 mm have pigment in at least the proximal axis of the filament. The stem axis is usually quite dark, often becoming lighter distally. Between the bulbs, the pigment is often light or absent proximally, becoming darker distally, and there is often a very dark spot or cap at the base of the distal bulb. The external chevron–shaped or roundish striated areas on the stem are usually prominently pigmented, except in the smallest specimens.
Both proximal and distal bulbs vary in shape from spheroidal to long ovoid, sometimes having the ends flattened or, in one case, widened distally (pear-shaped). The bulbs are relatively small in some small specimens, but by about 70 mm both bulbs have attained dimensions that do not change relative to SL with growth. The proximal bulb in specimens larger than 60 mm is 0.6%–1.5% SL; the distal bulb in all over 70 mm is 0.9%–1.6%. In most specimens, the distal bulb is 1.0–1.6 times as long as the proximal bulb, but in small specimens the ratios are 0.5–2.0.
The distance between terminal bulbs is 2.2%–4.2% SL, apparently not changing with growth, and usually is 2–3 times the length of the distal bulb (in the smallest specimens the interspace is up to 7.8 times the distal bulb).
The terminal filament is long, 22%–33% SL when intact, without apparent change in relative length with growth. Short side branches are present occasionally, arising variously from close to the bulb to well distad on the filament. Four of our specimens had a single such branch, 1 had 2 together. Tiny bulblets are present along the filament axis but are difficult to discern in most specimens; they tend to be slightly larger and more prominent proximally.
The postorbital organs of 7 large males (112–132 mm) are relatively small, 1.2%–1.4% SL, 38%–50% of fleshy–orbit length. A male of 110 mm has an organ only 0.9% SL, indicating that enlargement begins at about this body size.
Beebe and Crane (1939:220) described the colors of the bulbs in a living male from Bermuda. The proximal bulb was translucent white, the distal bulb clear pink. In our observations of 4 males and 3 females from Bermuda and south, the proximal bulb varied from almost white to pink, while the distal bulb was pink to pinkish purple. The postorbital organs were white in both sexes. No sexual dimorphism in color is apparent.
Barbel length increases from 22% SL in the smallest specimen (48 mm) to 60%–85% in those longer than 100 mm. All specimens have black pigment in the axis of the stem and between the bulbs, and specimens larger than 80 mm have pigment in at least the proximal axis of the filament. The stem axis is usually quite dark, often becoming lighter distally. Between the bulbs, the pigment is often light or absent proximally, becoming darker distally, and there is often a very dark spot or cap at the base of the distal bulb. The external chevron-shaped or roundish striated areas on the stem are usually prominently pigmented, except in the smallest specimens.
Both proximal and distal bulbs vary in shape from spheroidal to long ovoid, sometimes having the ends flattened or, in one case, widened distally (pear–shaped). The bulbs are relatively small in some small specimens, but by about 70 mm both bulbs have attained dimensions that do not change relative to SL with growth. The proximal bulb in specimens larger than 60 mm is 0.6%– 1.5% SL; the distal bulb in all over 70 mm is 0.9%–1.6%. In most specimens, the distal bulb is 1.0–1.6 times as long as the proximal bulb, but in small specimens the ratios are 0.5–2.0.
The distance between terminal bulbs is 2.2%– 4.2% SL, apparently not changing with growth, and usually is 2–3 times the length of the distal bulb (in the smallest specimens the interspace is up to 7.8 times the distal bulb).
The terminal filament is long, 22%–33% SL when intact, without apparent change in relative length with growth. Short side branches are present occasionally, arising variously from close to the bulb to well distad on the filament. Four of our specimens had a single such branch, 1 had 2 together. Tiny bulblets are present along the filament axis but are difficult to discern in most specimens; they tend to be slightly larger and more prominent proximally.
The postorbital organs of 7 large males (112–132 mm) are relatively small, 1.2%–1.4% SL, 38%–50% of fleshy–orbit length. A male of 110 mm has an organ only 0.9% SL, indicating that enlargement begins at about this body size.
Beebe and Crane (1939:220) described the colors of the bulbs in a living male from Bermuda. The proximal bulb was translucent white, the distal bulb clear pink. In our observations of 4 males and 3 females from Bermuda and south, the proximal bulb varied from almost white to pink, while the distal bulb was pink to pinkish purple. The postorbital organs were white in both sexes. No sexual dimorphism in color is apparent.
Two terminal bulbs separated by a long interspace (2.2%–4.2% SL; usually 2–3 times length of distal bulb, but up to 7.5 times in some small specimens). Barbel 60%–85% SL in specimens over 100 mm. Terminal filament long, 22%–33% SL when intact, rarely with 1 or 2 short branches. Distal bulb usually 0.9%–1.6% SL, 1.0–1.6 times length of proximal bulb (0.5–2.0 times in small specimens). Axis of stem pigmented, usually darkly. External chevron-shaped or roundish striated areas on stem usually pigmented in specimens larger than 80 mm. Paired dorsal spots between occiput and dorsal-fin origin usually 8, occasionally 7.
Two terminal bulbs separated by a long interspace (2.2%–4.2% SL; usually 2–3 times length of distal bulb, but up to 7.5 times in some small specimens). Barbel 60%–85% SL in specimens over 100 mm. Terminal filament long, 22%–33% SL when intact, rarely with 1 or 2 short branches. Distal bulb usually 0.9%–1.6% SL, 1.0–1.6 times length of proximal bulb (0.5–2.0 times in small specimens). Axis of stem pigmented, usually darkly. External chevron–shaped or roundish striated areas on stem usually pigmented in specimens larger than 80 mm. Paired dorsal spots between occiput and dorsal–fin origin usually 8, occasionally 7.
Known from the North Atlantic west of 50°W between 25° and 40°N. Two specimens have been taken in the northern Bahamas. The 149.6-mm specimen from north of Puerto Rico recorded by Morrow and Gibbs (1964) was tentatively reidentified as bimargaritatus by Gibbs et al. (1983).
Known from the North Atlantic west of 50°W between 25° and 40°N. Two specimens have been taken in the northern Bahamas.
Gibbs RH, Jr, Clarke TA, Gomon JR. 1983. Taxonomy and distribution of the stomioid fish genus Eustomias (Melanostomiidae), I: Subgenus Nominostomias. Smithsonian Contributions to Zoology 380:1–139.
Gibbs RH, Jr, Clarke TA, Gomon JR. 1983. Taxonomy and distribution of the stomioid fish genus Eustomias (Melanostomiidae), I: Subgenus Nominostomias. Smithsonian Contributions to Zoology 380:1–139.
Eustomias bibulbosus is a member of the subgenus Nominostomias Reagan and Trewavas (1930). The following description from Gibbs et al. (1983) applies to all members of Nominostomias.
Three well-developed, free pectoral rays. Seven pelvic rays. Barbel with slender stem having little or no external pigment (axis often pigmented), no row of dark spots, and no branches proximal to the terminal bulbs (E. multifilis may have a few short filaments on the stem near the bulb). One or 2 relatively small terminal bulbs, the distalmost with a projection or filament of variable complexity (the projection almost indiscernible in a few species). No wide ventral body groove posterior to pectoral–fin base (a narrow, shallow groove observed in some specimens). Photophore and vertebral counts high. Photophores in ventral series (IC) 69–80 (seldom fewer than 72, species modes mostly 75–78), in lateral series (OC) 63–73 (seldom fewer than 66, species modes mostly 69–72), VAV and VAL 15–21 (seldom fewer than 16, species modes 17–18 and 18– 19, respectively). Vertebrae in continuous series 64–71 (seldom fewer than 65, species modes mostly 67–69). No paired photophores in lateral series. Number of teeth high: premaxillary 11–20, mandibular 14–29 in large specimens (fewer in many specimens less than 100 mm SL).
Counts of fin-rays, photophores, vertebrae, and teeth are of little use in distinguishing most species of Nominostomias, for even those species that show modal differences overlap the ranges of most other species.
None of the body proportions examined by Gibbs et al. (1983) showed convincing differences among species of Nominostomias. Differences in size or relative-growth patterns appeared to characterize a number of species for which few specimens were measured, but these are believed to be artifacts of sampling. The cloud of points of species with abundant measurements usually encompassed those of species with few measurements, and in those abundant species, isometric growth is indicated for almost every body part once metamorphosis is complete. The only body measurement to indicate allometric growth is the least caudal-peduncle depth, which decreases relative to SL.
Beebe W, Crane J. 1939. Deep–sea fishes of the Bermuda Oceanographic Expeditions. Zoologica (New York) 24:65–238.
Gibbs RH, Jr, Clarke TA, Gomon JR. 1983. Taxonomy and distribution of the stomioid fish genus Eustomias (Melanostomiidae), I: Subgenus Nominostomias. Smithsonian Contributions to Zoology 380:1–139.
Beebe W, Crane J. 1939. Deep-sea fishes of the Bermuda Oceanographic Expeditions. Zoologica (New York) 24:65–238.
Gibbs RH, Jr, Clarke TA, Gomon JR. 1983. Taxonomy and distribution of the stomioid fish genus Eustomias (Melanostomiidae), I: Subgenus Nominostomias. Smithsonian Contributions to Zoology 380:1–139.
Morrow JE, Jr., Gibbs RH, Jr. 1964. Family Melanostomiatidae. Fishes of the Western North Atlantic 1, pt. 4:351–522.
Parr AE. 1927. The stomiatoid fishes of the suborder Gymnophotodermi (Asthronesthidae, Melanostomiatidae, Idiacanthidae) with a complete review of species. Bulletin of the Bingham Oceanographic Collection 3:1–123.
Regan CT, Trewavas E. 1930. The fishes of the families Stomiatidae and Malacosteidae. Danish Dana Expedition 1920−22 6:1−143.
To at least 137 mm SL.
To at least 137 mm SL.
Tongue of the Ocean, Bahamas, 23°58'N, 77°26'W, 7000 feet wire out.
Tongue of the Ocean, Bahamas, 23°58'N, 77°26'W, 7000 feet wire out.
Holotype: YPM 2039.
Holotype: YPM 2039.
