Sand collar

Sand collar

Sand collars are the egg masses of certain sea snails, marine gastropod mollusks in the family Naticidae, sometimes known as "moon snails".

These egg masses often wash up on sandy beaches, either whole or sometimes in fragments. When they are whole, sand collars are shaped like an old-fashioned detachable shirt or blouse collar (hence the name). They consist of sand grains cemented together by a gelatinous matrix, with embedded eggs.

A fresh sand collar feels hard, plasticky and dead, but in reality each sand collar contains thousands of capsules, each one housing one or several live embryos. In species with planctonic development, these embryos hatch out as bilobed veligers. After the eggs hatch, the sand collar disintegrates.

References

* Bandel, K. (1999) On the origin of the carnivorous "gastropod" group Naticoidea (Mollusca) in the Cretaceous with description of some convergent but unrelated groups. Greifswalder Geowissenschaftliche Beiträge, 6, 134-175.
* [http://www.mapress.com/zootaxa/2008/f/zt01770p040.pdf Huelsken T. "et al" (2008)] The "Naticidae" (Mollusca: Gastropoda) of Giglio Island (Tuscany, Italy): Shell characters, live animals, and a molecular analysis of egg masses. Zootaxa, 1770, 1-40.


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  • Sand collar — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

  • sand collar — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

  • sand collar — noun : the mass of eggs embedded in sand and jellylike matter that is produced by a moon shell and is shaped like a thin collar or bottomless saucer open at one side …   Useful english dictionary

  • Sand — Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent when …   The Collaborative International Dictionary of English

  • Sand badger — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

  • Sand bag — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

  • Sand ball — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

  • Sand bath — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

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  • Sand birds — Sand Sand, n. [AS. sand; akin to D. zand, G. sand, OHG. sant, Icel. sandr, Dan. & Sw. sand, Gr. ?.] 1. Fine particles of stone, esp. of siliceous stone, but not reduced to dust; comminuted stone in the form of loose grains, which are not coherent …   The Collaborative International Dictionary of English

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