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Mermaid's Necklace

Busycon carica


This has turned out, to my surprise, to be the egg case of the Knobbed Whelk (Busycon carica), a mollusk of the Family Buccinidae. It was tightly coiled, brittle but flexible and felt like chitin. It stretched out to about 33 cm, and that was obviously only a piece. Several of these (of different lengths) washed up on the beach. Gulf of Mexico, Sihoplaya (south of Campeche City), Campeche. They are commonly called Mermaid Necklaces or Venus's Necklace. A few miles farther down the coast we bought a Whelk Shell from a vendor on the street. That big shell has turned out to be the actual Knobbed Whelk, the adult shell of my Mermaid Necklace! (Last 2 pictures).


Small beach strip among many rocks and heavy surf.


This Whelk is a predator, feeding on other shells, especially bivalves. The egg case is a string of flat capsules containing up to 90 eggs each and are connected on one side so that they form a spiral. Not all eggs hatch and if you look closely, you can see eggs within some of the cases. The female buries the end of the chain in the sand so that the eggs can develop and hatch without washing up on the beach.

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LaurenZarate 8 years ago

Thank you Luis, Machi and Leuba. I was totally surprised. I had never seen these before and the egg cases of a Mollusk would have been my last choice! I still can't imagine how the animal make these.

Leuba Ridgway
Leuba Ridgway 8 years ago

Machi is right, it is the egg case of a marine mollusc - like this one

Nice spotting !

Machi 8 years ago

whelk or conch eggs I think

LuisStevens 8 years ago


Spotted by

Villa Madero, Campeche, Mexico

Spotted on Feb 25, 2015
Submitted on May 5, 2015

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