Otitoma elegans, Morassi & Nappo & Bonfitto, 2017

Morassi, Mauro, Nappo, Andrea & Bonfitto, Antonio, 2017, New species of the genus Otitoma Jousseaume, 1898 (Pseudomelatomidae, Conoidea) from the Western Pacific Ocean, European Journal of Taxonomy 304, pp. 1-30 : 20

Otitoma elegans sp. nov.

urn:lsid:zoobank.org:act:0BBFAA0A-95F9-4068-A7D0-9A7A68E2F03E

Fig. 5 I–O

Etymology

The specific epithet refers to the Latin ‘ elegans ’, meaning ‘characterized by refined grace’, alluding to the aesthetically pleasant appearance of the shell.

Type material

Holotype

FIJI ISLANDS: BORDAU 1, Stn DW 1465, 18°09 ′ S, 178°39 ′ W, 290–300 m ( MHNH IM-2000-32606 ).

Description

Shell fusiform (b/l 0.38; a/l 0.55). Teleoconch of slightly less than 7 convex whorls, with periphery at middle of the 3 earliest whorls, posterior to mid-whorl on the later whorls. Whorls separated by a distinct suture bordered by a spiral cord. Sutural ramp moderately concave. Axial sculpture consisting of opisthocline ribs, subequal to broader than intercostal spaces, extending on spire whorls from suture to abapical side of sutural ramp, prominent on earlier whorls, but becoming remarkably weaker on last whorl. 21 axial ribs on penultimate whorl and 17 on last whorl. Spiral sculpture consists of widelyspaced, narrow, weakly prominent spiral cords, somewhat plicate where crossing axial ribs. Earliest three whorls with two cords between sutural ramp and abapical suture, increasing to three cords on fourth and antepenultimate whorls and four on penultimate and last whorls. Last whorl with 13 spiral cords on base and rostrum. Insterpaces between cords sculptured by numerous fine spiral threads (up to 14) ( Fig. 5 K–L). Aperture rather narrow, lanceolate, constricted at entrance to siphonal canal. Siphonal canal moderately long, not notched terminally. Inner lip with moderately thin callus, parietal region with a pad formed by termination of outer lip. Outer lip edge sharp, preceded by a wide, low, rounded varix. Anal sinus moderately deep, apically rounded, asymmetrically U-shaped, not strongly constricted at opening. Stromboid notch moderately deep. Protoconch of 1½ smooth, domed whorls with few sparse microscopic granules when observed under SEM ( Fig. 5N ), diameter 0.86 mm. Color yellowish-white with brown-orange spiral cords.

Dimensions

Holotype: 12.6 × 4.8 mm, aperture height 7.0 mm.

Remarks

Although only a single specimen of Otitoma elegans sp. nov. is available, this species differs distinctly from its described congeners in having only a few, widely-spaced primary spiral cords with well developed secondary spiral sculpture, and a peculiar color pattern (yellowish-white with brown-orange spiral cords). O. elegans sp. nov. further differs from its congeners of similar size in possessing a paucispiral and domed protoconch instead of multispiral and conical.

Figures

Fig. 5. [next page] A–H. Otitoma rubiginostoma sp. nov. A–B. Holotype (MNHN IM-2000- 32604), MUSORSTOM 4, Stn DW151, New Caledonia, 19°07′ S, 163°22′ E, 200 m, 4.7 × 1.8 mm. C–H. Paratype 2 (MZB 60214), MUSORSTOM 4, Stn DW149, New Caledonia, 19°08′ S, 163°23′ E, 155 m. D. Teleoconch. E. Secondary spiral sculpture of the teleoconch. F–G Protoconch. H. Microsculpture of the protococonch. — I–O. Otitoma elegans sp. nov. I–J. Holotype (MNHN IM-2000-32606), BORDAU 1, Stn DW1465, Fiji Island, 18°09′ S, 178°39′ W, 290–300 m, 12.6 × 4.8 mm. K. Teleoconch (not coated). L. Secondary spiral sculpture of the teleoconch (not coated). M, O. Protoconch (not coated). N. Microsculpture of the protococonch. — P–U. Otitoma philippinensis sp. nov. P–Q. Holotype (MZB 60215), Philippines, Nocnocan Island, 180–250 m, trawled by fishermen, 15.4 × 5.25 mm. R. Teleoconch (not coated). S. Secondary spiral sculpture of the teleoconch (not coated). T–U. Protoconch (not coated). Scale bars: C, K = 1 mm; D, F–G, L–N, S–U = 100 µm; E, H, O = 50 µm; R = 500 µm.