Sciences marines : recherche et développement

Abstrait

Variation in Shell Morphology and Adult Specimen Weight in Three Varieties of a Commercially Important Gastropod Turbinella Pyrum (Linnaeus, 1767) From Southeast Coast of India

Sabapathi Arularasan, Viswanathan MS, Venmathi Maran BA, Galib Uz Zaman and Chandra Shekar M

Using morphological traits including weight, the genetic group effect in three varieties of Turbinella pyrum was determined. A total of 300 T. pyrum individuals (100 per variety) were used. The morphometric analysis showed that the shell outer lip thickness and operculum width were found to be significantly different in between the three varieties of T. pyrum. The study also showed that the shell length, body whorl length and operculum length significantly differed in between G1 (var. obtusa) and G2 (var. acuta synonymous T. rapa) and shell width differed significantly in between G2 (var. acuta) and G3 (var. globosa). The effect of genetic group on the shell depth and adult animal weight were found to be non-significant. The observed mean length, width and depth in G1 genetic group (var. obtusa) supports its higher market value in comparison to the other two genetic groups studied. This variety has moderate lip thickness, which may be another reason for its higher demand in bangle industry than the other two genetic groups. The G2 (var. acuta) and G3 (var. globosa) genetic groups although comparatively larger, have a disproportionate body size then G1 (var. obtusa). The standardized shell morphological characters in present study are helpful to draw primary guidelines for identification of three T. pyrum varieties studied. The present morphometry data on T. pyrum varieties also plays key role for species description and also for their domestication.