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The Conus Biodiversity Website

CATALOGUE OF RECENT AND FOSSIL CONUS

  Conus shikamai Coomans. Moolenbeek & Wils, 1985.

Range: Taiwan to Philippines, Indonesia (Sulawesi).

Description: Medium-sized to moderately large, moderately solid to solid. Last whorl usually conical, outline slightly convex below shoulder, then straight. Shoulder angulate, irregularly undulate to weakly tuberculate. Spire low, outline concave. Larval shell of 3-3.5 whorls, maximum diameter 0.8-0.9 mm. First 3 postnuclear whorls weakly tuberculate to irregularly undulate; adjacent whorls nearly smooth, late whorls undulate. Teleoconch sutural ramps slightly concave, with 2-3 increasing to 4-6 spiral grooves, obsolete in latest whorls. Last whorl with variably spaced spiral ribs at base.

Shell Morphometry
  L 45-70 mm
  RW 0.17-0.45 g/mm
     (L 45-60 mm)
  RD 0.49-0.53
  PMD 0.85-0.94
  RSH 0.04-0.08

Ground colour pale bluish violet. Last whorl with a broad, usually continuous, brown spiral band on each side of centre and with brown axial flames, usually crossing spiral bands and adjacent ground-colour areas. Rather evenly spaced, fine dark brown spiral lines cover entire last whorl of subadult specimens but are mainly restricted to the brown spiral bands in adult shells. Larval whorls brown. Teleoconch sutural ramps heavily maculated with dark brown radial markings. Aperture violet.

Periostracum olive, thin, translucent, with widely spaced spiral rows of tufts on last whorl, including shoulder.

Habitat and Habits: Generally in 100-240 m.

Discussion: The earlier name proved unavailable according to the rules of the ICZN, and Coomans et al. (1985a) renamed this species C. shikamai. C. shikamai is similar to C. recluzianus, C. sukhadwalai, and C. voluminalis. C. recluzianus in all its forms can generally be separated by the presence of distinct spiral grooves on late sutural ramps, the regularly spaced undulation or tuberculation of the shoulder, the coarser spiral lines on the last whorl, and the thicker, less translucent periostracum with heavier tufts. C. recluzianus from Japan and Taiwan (including form urashimanus and form gloriakiiensis) also has a broader last whorl (RD 0.53-0.60) and different colouration. C. recluzianus from the Indian Ocean may look similar because of its pronounced spiral lines, but has a white ground colour. Form roseorapum of C. recluzianus can also be distinguished by the more prominent tuberculation of its late postnuclear whorls, its different colouration, and by the absence of pronounced spiral lines from its last whorl. C. sukhadwalai differs from C. shikamai in having a distinctly broader and less straight-sided last whorl (RD 0.59-0.66), smooth postnuclear whorls, and absence of spiral lines from its last whorl. For comparison with C. voluminalis, see the Discussion of that species.

Range Map Image

C. shikamai Range Map

This section contains verbatim reproductions of the accounts of 316 species of Conus from the Indo-Pacific region, from Manual of the Living Conidae, by Röckel, Korn and Kohn (1995). They are reproduced with the kind permission of the present publisher, Conchbooks.

All plates and figures referred to in the text are also in Röckel, Korn & Kohn, 1995. Manual of the Living Conidae Vol. 1: Indo-Pacific Region.

The range maps have been modified so that each species account has it own map, rather than one map that showed the ranges of several species in the original work. This was necessary because each species account is on a separate page on the website and not confined to the order of accounts in the book.

 

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