Bufoceratias microcephalus Ho, Kawai & Amaoka

Ho, Hsuan-Ching, Kawai, Toshio & Amaoka, Kunio, 2016, Records of deep-sea anglerfishes (Lophiiformes: Ceratioidei) from Indonesia, with descriptions of three new species, Zootaxa 4121 (3), pp. 267-294 : 271-273

Bufoceratias microcephalus Ho, Kawai & Amaoka , sp. nov.

New English name: Small-head toady seadevil Figs. 5 A–B, 6A; Table 1

Holotype. HUMZ 193747 (151.0), st. 29, 8°31.3'S, 110°25.0'E – 8°30.8'S, 110°23.6'E off Java, Indonesia, eastern Indian Ocean, 755–770 m, 13 May 2005.

Diagnosis. A species of Bufoceratias characterized by a small and narrow head; small mouth, reflected by shorter jaws; relatively small and more numerous teeth on both jaws; moderately long illicium; large esca bearing large bulb-like terminal papilla, about equal to size of esca, simple filament-like posterior appendage and pair of short simple filament-like lateral appendages; and lack of anterior appendage.

Description. Dorsal-fin rays 6; pectoral-fin rays 14; anal-fin rays 4; caudal-fin rays 9. Teeth on vomer 11 (6, 5); upper jaw teeth 97 (45, 52); lower jaw teeth 67 (33, 34). Head length 36.6% SL; head depth 39.4; head width 26.3; frontal width 12.2; illicial length 70.0; distance between upper jaw symphysis and origin of illicium 40.4; upper jaw length 29.5; lower jaw length 35.6; total length of esca 21.3.

Body slightly elongated compared to three congeners, its depth about 1.2 in length, somewhat compressed, oval profile when viewed from lateral side. Mouth relatively small, cleft not reaching eye, oblique. Oral valve well developed, lining inside of both jaws. Single tube-like nostril about midway between eye and mouth. Teeth short on both jaws and vomer, length of longest teeth on upper jaw 2.5% SL, on lower jaw 3.0% SL. Teeth present on pharyngobranchial II and III.

Illicium moderately long, emerging from dorsal surface of head behind sphenotic spines. Entire pterygiophore of illicium concealed beneath skin. Second cephalic spine beneath skin just behind base of illicium; a small pore behind base of illicium.

Esca large, its length 10.5% SL and width 6.8% SL, bearing very large bulb-like terminal papilla, about size of escal bulb, its length 10.8% SL and width 6.8% SL; single filament-like posterior appendage, length 15.2% SL, simple and colorless; pair of short filament-like lateral appendages, length 4.2% SL (one side much shorter than other possibly due to damage); large posterior pore at base of terminal papilla.

Body, including the illicium, esca and escal terminal papilla, covered by feeble and tiny dermal spines.

Coloration. Uniformly blackish, except for grayish rays of dorsal, anal and caudal fins and transparent inter-radial membranes. Middle portion of escal terminal papilla pigmented, base and tip semi-transparent; escal appendages transparent.

Etymology. Named for the relatively small head of this species compared to that of all other congeners.

Distribution. Known only from the holotype collected off Java, Indonesia at a depth on 755– 770 m. Remarks. A comparison on selected morphometric and meristic data for recognized species in the genus are shown in Table 1 .

B. microcephalus B. thele B. wedli B. cf. wedli B. shaoi sp. nov.

Standard length (mm) 151.0 39.5–127.4 (n=3) 51.0–127.0 131.2 33.5–52.5

(n=7) (n=1) (n=5) Bufoceratias microcephalus sp. nov. can be easily separated from all three congeners by its relatively small head, the length 36.6% SL (vs. 39.0–53.4% SL in congeners) and depth 39.4% SL (vs. 46.5–66.6% SL); narrow head, the width 26.4% SL (vs. 30.1–43.1% SL) and frontal width, 12.2% SL (vs. 13.3–17.0% SL); small mouth reflected by short jaws, upper jaw length 29.5% SL (vs. 36.2–49.9% SL) and lower jaw length 35.6% SL (vs. 37.7–57.5% SL); moderately long illicium, its length 70.0% SL, which is shorter than that of B. wedli (99.7– 147.4% SL, n=12) and B. thele (111.1–174.4% SL, n=3), but longer than that of B. shaoi (24.8–40.0% SL, n=9); more numerous jaw teeth (97 vs. 25–53 on upper jaw, 67 vs. 23–44 on lower jaw); relatively small jaw teeth, the length of longest teeth on upper jaw 2.5% SL (vs. 3.0–7.8% SL) and on lower jaw 3.0% SL (vs. 5.0–9.4% SL); and a different escal morphology with a relatively large esca bulb, a very large bulb-like terminal papilla, a slender simple filament-like posterior appendage and a pair of short, simple filament-like lateral appendages. Although represented by only a single specimen, the above-mentioned characters readily distinguish it from all other congeners.

Figures

FIGURE 5. Holotype of Bufoceratias microcephalus Ho, Kawai & Amaoka, sp. nov. A. HUMZ 193747, 151.0 mm SL, preserved. B. Esca of the holotype. AL, anterolateral escal appendage. PA, posterior escal appendage. PP, posterior pore. TP, termianl papilla.