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Popis
Range: Golf of Mannar and along the Kerala coast, southwestern India.
Habitat: Trawled in deep water on soft substrate.
Description: Shell, solid with a silky surface, ovate or elongate fusiform, of between 80 and 120 mm in length. Protoconch papillary with three raised whorls, chocolate or flesh coloured. Spire short or elongate with shouldered whorls. Teleoconch with five and a half whorls. Sculpture of 19-20 axial ribs on the two first whorls crossed by fine spiral striae, body whorl smooth or bearing faint knobs in most specimens. Aperture semi-ovate. Outer lip beveled and simply thickened. Columella straight bearing three strong beige coloured plaits followed adapically by four to five weaker ones. Fasciole indistinct. Siphonal notch narrow. On a flesh background colour, the pattern consists of 20-25 large, slighty weavy brown axial lines covering the entire shell. These lines are variable in breadth, sometimes interrupted or forming curls or sometimes crossed by three revolving rows of brown blotches. Two forms occur in the Indian waters, varying in cline from the South to the North:
- forma loroisi s.s. (forma A in Poppe & Goto, 1992): small sized with a short spire and very convex smooth whorls, similar to H. lapponica lapponica. Axial pattern is rather thin and almost parallel. The form is dominant in the southern part of the range.
- forma "keralensis" (forma B in Poppe & Goto, 1992): medium sized with an elongated spire with less convex and mostly knobbed whorls. Axial pattern is thick and dark and tends to be irregular. This population is mostly found along the Kerala Coast.
Animal: Not available for study.
Comparison: Confusion is not possible in the northern part of its range, off Ernakulam, where the shells have the typical "keralensis'-form. Towards the south, off Kolachel, shells tend to be smaller with axial lines formed by closely spaced dashes resembling the pattern found in some H. lapponica lapponica. So distinction becomes difficult between this latter population and the Palk Strait-population of H. lapponica bearing loroisi-pattern . The shape of the shell is not a specific character to separate these two species, but weight and surface characteristics are: loroisi is a rather light shell with a silky surface; lapponica is a robust shell with a duller surface. However some rare specimens are impossible to sort and can be considered intermediate. Close relationship between the two species is obvious and question of their conspecificity has been discussed. Weaver & duPont (1970) deleted this species into synonymy with lapponica, based upon the existence of scarce uncertain specimens. Nevertheless, apart from the existence of intermediate shells in a very narrow area, geographical and conchological divergence is advanced enough to justify the status of separate taxa at valid subspecies.
Remarks: Development of commercial fisheries has yielded many specimens and this species is common now.
Habitat: Trawled in deep water on soft substrate.
Description: Shell, solid with a silky surface, ovate or elongate fusiform, of between 80 and 120 mm in length. Protoconch papillary with three raised whorls, chocolate or flesh coloured. Spire short or elongate with shouldered whorls. Teleoconch with five and a half whorls. Sculpture of 19-20 axial ribs on the two first whorls crossed by fine spiral striae, body whorl smooth or bearing faint knobs in most specimens. Aperture semi-ovate. Outer lip beveled and simply thickened. Columella straight bearing three strong beige coloured plaits followed adapically by four to five weaker ones. Fasciole indistinct. Siphonal notch narrow. On a flesh background colour, the pattern consists of 20-25 large, slighty weavy brown axial lines covering the entire shell. These lines are variable in breadth, sometimes interrupted or forming curls or sometimes crossed by three revolving rows of brown blotches. Two forms occur in the Indian waters, varying in cline from the South to the North:
- forma loroisi s.s. (forma A in Poppe & Goto, 1992): small sized with a short spire and very convex smooth whorls, similar to H. lapponica lapponica. Axial pattern is rather thin and almost parallel. The form is dominant in the southern part of the range.
- forma "keralensis" (forma B in Poppe & Goto, 1992): medium sized with an elongated spire with less convex and mostly knobbed whorls. Axial pattern is thick and dark and tends to be irregular. This population is mostly found along the Kerala Coast.
Animal: Not available for study.
Comparison: Confusion is not possible in the northern part of its range, off Ernakulam, where the shells have the typical "keralensis'-form. Towards the south, off Kolachel, shells tend to be smaller with axial lines formed by closely spaced dashes resembling the pattern found in some H. lapponica lapponica. So distinction becomes difficult between this latter population and the Palk Strait-population of H. lapponica bearing loroisi-pattern . The shape of the shell is not a specific character to separate these two species, but weight and surface characteristics are: loroisi is a rather light shell with a silky surface; lapponica is a robust shell with a duller surface. However some rare specimens are impossible to sort and can be considered intermediate. Close relationship between the two species is obvious and question of their conspecificity has been discussed. Weaver & duPont (1970) deleted this species into synonymy with lapponica, based upon the existence of scarce uncertain specimens. Nevertheless, apart from the existence of intermediate shells in a very narrow area, geographical and conchological divergence is advanced enough to justify the status of separate taxa at valid subspecies.
Remarks: Development of commercial fisheries has yielded many specimens and this species is common now.
Bail, P. & Poppe, G.T., 2004. The Tribe Lyriini. A Revision of the Recent Species of the Genera Lyria, Callipara, Harpulina, Enaeta and Leptoscapha.
Autor: Jan Delsing