08 August 2012

Sinistral Turbinella pyrum


The Harvard Museum of Natural History currently has an exhibit entitled Mollusks: Shelled Masters of the Marine Realm, showcasing 300 of the museum's ten million specimens.
A display case devoted to snails contains two shells of the same species of Indian sacred chank (Turbinella pyrum). One is coiled with an opening to the right, the usual thing; the other has its opening to the left. There are only three known examples of such a left-facing shell in the United States... A local amateur shell collector has observed that the shell is so valuable in the marketplace that armed guards should be positioned on either side of the case 24/7.
I found the photo of dextral and sinistral Turbinella at Reverse Coiled Gastropods:
A vast majority of the tens of thousands of marine and non-marine gastropod species are normally dextral (right handed - i. e., the shell opening is to the right when held spire upwards) while only a limited number of taxa such as Busycon sinistrum, the few species of the Fasciolariid subgenus Sinistralia and most of the speciose family Triphoridae, among others, are normally sinistral (left handed - the shell opening is to the left when held spire upwards). However, accidents of nature do happen, and occasionally a sinistral specimen of a normally dextral species or a dextral specimen of a normally sinistral species will be found - albeit rarely.

 In some 40 years of specializing in "reverse coiled" or "abnormally sinistral or dextral" gastropods, Jacksonville amateur malacologist Harry G. Lee has assembled a collection of 164 individual species which had coiled in a direction contrary to the norm. This collection includes 102 Recent, three fossil marine and 59 non-marine species.

1 comment:

  1. The Indian sacred conch of the species Turbinella pyrum (Sinistral variety) has three main localities in India as under. The Gulf of Kutch (North West Coast); Bay of Bengal and Rameshwaram, Kanya Kumari (Near Adam's Bridge or Ramsetu) in the South India. Shells from all these three localities show morphological difference. Shells from Bay of Bengal are giant in size. Specimens more than Three feet and weighing more than 10 Kg have been recorded. I have standardized protocol to take X-Ray images of these shells for its authenticity. I have wonderful collection of Sinistral Turbinella pyrum and sea shell collectors are Welcome to visit my place in Poona, India to see this collection. In India this shell is sold on weight basis. Thanks.

    Dr. Chandrashekhar Phadke, Poona, Maharashtra, I
    chphadke@gmail.com

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