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The Conus Biodiversity Website


  Conus inscriptus Reeve, 1843.

Range: Indian Ocean, from Natal to Red Sea and to W. Thailand.

Description: Medium-sized to moderately large, usually moderately solid to solid; shells from Mascarenes, Aden and Red Sea smaller than those from other areas. Last whorl ventricosely conical to conical; outline convex at adapical fourth to half, usually straight below; left side sometimes concave near base and convex at adapical two-thirds. Shoulder angulate to subangulate. Spire of low to moderate height, highest in shells from Somalia to Mozambique; outline concave to straight, most frequently straight and sometimes with stepped whorls in E. African shells (e.g., P1. 38, Fig. 12). In specimens from Mozambique, larval shell of about 3 whorls, maximum diameter 0.7- 0.8 mm; in specimens from W. Thailand, larval shell of about 1.75 whorls, maximum diameter also 0.7-0.8 mm. First 2-4 postriuclear whorls weakly to distinctly tuberculate, sometimes only first whorl with obsolete tuberculation. Teleoconch sutural ramps flat to moderately concave, with 1 increasing to 3-8 spiral grooves, often additional spiral striae in latest whorls; on shoulder ramp, spiral sculpture sometimes consists of 13-15 fine and nearly equal spiral grooves. Last whorl with widely spaced, weak to pronounced spiral grooves separated by ribbons on basal third to two-thirds; anteriorly, grooves are wide, often contain spiral threads or fine ribs, and are separated by narrow ribbons or ribs; in E. African specimens, ribbons may have fine to coarse granules at adapical edge.

Shell Morphometry
  L 40-74 mm
     (32-44 mm Mascarenes, Aden, Red Sea)
  RW 0.09-0.44 g/mm
     (L 32-74 mm)
  RD 0.51-0.68
     (India; 0.55-0.64 Adaman Sea; 0.52-0.63 W. Indian Ocean)
  PMD 0.79-0.90
  RSH 0.10-0.15
     (India, W. Thailand, Mauritius, Réunion; 0.10-0.23 Somalia to Mozambique)

Ground colour white to beige or pale orange. Last whorl with spiral rows of brown or orange dots, spots, bars or axial streaks, fusing into axial flames and blotches and forming interrupted spiral bands below shoulder and within adapical and abapical thirds. Subshoulder band usually less prominent than anterior bands, sometimes absent. Larval whorls white to beige, adjacent 2 postnuclear sutural ramps of same colour. Following sutural ramps with radial lines to blotches, usually extending over outer margins, matching last whorl pattern in colour. White shells without any pattern remnants occur in the eastern part of the range (Pl. 38, Figs. 16, 17). Aperture white, beige to orange, pinkish or bluish violet, or pink; in E. African shells, coloured area often with a darker collabral band.

Periostracum brown, thin, translucent, and smooth.

Radular teeth with 3 adapical barbs (Peile, 1939).

Habitat and Habits: In 5-85 m, most frequently reported from 40-80 m, sometimes as deep as 150 m.

Discussion: C. inscriptus resembles C. jickelii, which is of similar size in its southern populations. The latter species can be distinguished by its non-tuberculate early postnuclear whorls and consistently brown first 2 teleoconch sutural ramps; sympatric C. inscriptus specimens also differ in their light or yellowish brown rather than dark reddish or bluish brown colour pattern and more sculptured last whorl. C. iodostoma differs in the bluish grey ground colour of its last whorl, and its spiral rows consist of small tan to reddish brown dots rather than orange brown dots and larger markings. The aperture of C. iodostoma has a paler rather than a darker peripheral band. C. ciderryi has a more conical last whorl (PMD 0.95-0.97), stronger tuberculate early and undulate late whorls. For comparison with C. collisus and C. stramineus, see the Discussions of the latter species. C. adenensis refers to E. African C. inscriptus, ranging from Natal as far north as Somalia (Pl. 38, Figs. 11-13). It is characterized by a somewhat higher spire (RSH 0.13- 0.23), a comparatively narrow last whorl (RD 0.52-0.59), and a pink or orange aperture that grades to violet toward southern E. Africa. Richard (1990) considered C. adenensis a valid species. In our opinion, the differences are not sufficient to merit distinction at the species level, and we provisionally consider C. i. adenensis a subspecies occurring along the East African coast. C. keatii is known from 2 type specimens from Seychelles (Pl. 38, Figs. 14, 15), which closely resemble C. i. adenensis in morphometry and colouration. Recently, more shells of this form have been found in Seychelles. In the Aden and Dahlak area, a variant of C. inscriptus (Pl. 38, Figs. 2, 3) has a consistently conical last whorl (RD 0.56-0.59; PMD 0.85-0.90), smaller size (to 44 mm) and may have a spire lower than that of E. African specimens. C. planiliratus and C. maculospira (Pl. 38, Figs. 9, 10) refer to shells from Burma and W. Thailand with a rather ventricose and prominently sculptured last whorl, a paucispiral larval shell, and a white aperture (Pl. 38, Fig. 10), while C. m. bangladeshianus (Pl. 38, Fig. 4) has a brownish orange ground colour and an orange aperture. These forms intergrade with one another and with C. inscriptus in S. India (Pl. 38, Figs. 5, 7, 8) and in the Andaman Sea. Almost completely white shells of C. inscriptus from India were described as C. cuneiformis (Pl. 38, Figs. 16-18). Yellow or orange specimens occur occasionally. C. inscriptus from the Mascarenes (Pl. 38, Figs. 20, 21) falls within the range of variation observed in shells from other regions. C. cavailloni seems to be an aberrant form of C. inscriptus; C. inscriptus f. meridionalis is a synonym of C. i. adenensis; C. keatiformis (Pl. 38, Fig. 6) is similar to shells from S. India. C. tegulatus (holotype: Pl. 70, Fig. 6), is probably a juvenile of C. inscriptus.

Range Map Image

C. inscriptus 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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