Metacrangon similis Komai, 1997

Komai, Tomoyuki, 2012, 3468, Zootaxa 3468, pp. 1-77 : 16-17

Metacrangon similis Komai, 1997

( Fig. 39)

Metacrangon sp. — Toriyama et al. 1990: 19, pl. 4a.

Metacrangon similis Komai, 1997b: 675 , figs 1H, 11, 12 [type locality: off Owase, Kumano Sea, 369–412 m]; 2011: 286, fig. 1D; Sakaji 2001: 210; De Grave & Fransen 2010: 458 (list).

Material examined. Holotype: off Owase , Kumano Sea, Japan, 34°05.8’N, 136°35.9’E, 369–412 m, 6 December 1005, baited trap, coll. Hideo Sekiguchi, female (cl 12.6 mm), CBM-ZC 3250.

Non-type material: Japan. SW of Shionomisaki , Kii Peninsula, 33°23.9’N, 135°38.9’E, 700 m, sand and rock, 2 October 1997, dredge, coll. S. Nagai, 1 male (cl 8.7 mm), CBM-ZC 3864 .

Diagnosis. Rostrum narrowly triangular with acute tip in dorsal view, ascending (angle against horizontal plane of carapace 20–40°), extending as far as antennal teeth; ventral surface non-carinate, rounded. Carapace with anterior tooth very strong, erect (angle against horizontal plane of carapace 60–80°), styliform, arising slightly posterior to rostral base, overlapping rostrum, tip slightly falling short of to reaching level of rostral tip; posterior tooth strong, hooked, arising at 0.60–0.70 of carapace length; submedian teeth present; antennal tooth strongly ascending in lateral view; branchiostegal tooth strong, directed somewhat laterally in dorsal view, slightly ascending in lateral view; postorbital angle rounded; orbital cleft present; branchial carina distinct; branchial region smooth. Abdomen weakly sculptured; first and second somites each with trace of middorsal carina, third to fifth somites each with moderately broad, distinct middorsal carina. First pleuron with acute to subacute ventral tooth, second and third somites each with blunt or subacute ventral or anteroventral tooth respectively, fourth pleuron with rounded anteroventral angle. Sixth abdominal somite with distinct submedian carinae. Eye 1.2–1.4 times longer than wide; dorsal tubercle rounded; cornea darkly pigmented, its width slightly less than 0.2 of carapace length. Antennular peduncle overreaching midlength of antennal scale; first segment with short distolateral process; stylocerite reaching distolateral process of first segment, terminating in blunt or subacute tooth; second segment with short blunt distolateral process. Antennal scale about 0.5 times as long as carapace, 2.5–2.9 times longer than wide; lateral margin nearly straight to faintly concave; distolateral tooth reaching or slightly overreaching lamella; lamella tapering distally to rounded distal margin. First pereopod with palm 2.9–3.4 times longer than wide.

Description. See Komai (1997b).

Size. Largest, ovigerous female cl 20.0 mm; largest male cl 10.0 mm.

Coloration. Body entirely dull violet; cornea darkly pigmented, reflective ( Komai 1997b).

Distribution. Restricted to the Pacific coast of Japan, from off Choshi, Chiba Prefecture to Tosa Bay; 450–

1000 m.