duplicata (Say, 1822) Sand Egg Collar.
are very common in southeast Florida, in the sand inside the third
reef at 65 fsw. I always assumed they were Sharkeye (Polinices
duplicatus) eggs, but I have never seen one being
made."Collectible Florida Shells" by R. Tucker Abbott also
ascribes them to P. duplicatus.
have found sand collars in New England cover with the egg cases of
the oyster drills. Could this be what you have found? If not from
the drills ( Urosalpinx cinerea ) maybe something similar. A good
book to check out egg cases in I found is the( A Golden Field Guide
) A Guide to Field Identification Seashells of North America. According
to this book the egg mass of the moon snails is a gelatinous mass
surrounded by the protective sand collar. Hope this is of some help.
thin, flexible walls flare to form an upright cylindrical crown and
having a wavy (plicated) basal margin; these are characteristic of
the Shark Eye moonsnail, Neverita duplicata (Say, 1822).
collars are unique to the family Naticidae and no other prosobranch.
A very useful feature of differentiating species is the uniqueness
of moonsnail egg cases, sand-encrusted gelatinous ribbons (Giglioli,
1955) and their resulting larval forms- planktonic/ crawl away (Bouchet
and Waren (1993).
(1955) developed a scheme of classification for naticid egg collars.
The egg collars of Atlantic intertidal species, Polinices heros, P.
duplicata, and P. triserata, were described by Gigliola 1952 and 1955
to Beatrice E. Winner in A Field Guide to Molluscan Spawn, vol 1.
(1987), the naticid sand collar is a single-layered structure of sand
grains held together by a gelatinous matrix. The sand grain size is
specific to the species - thus the grains in a Natica canrena collar
are larger than those in a Neverita duplicata collar. The eggs are
minute and are embedded in the collar. If the collar is held up to
a strong light (back lit), the egg cases can be seen as numerous transparent
sections in the collar. Tom E.
egg cases produced by naticid gastropods (moon snails). The most common
genus is Polinices. These same snails produced the tapered drill holes
you find in clams; they're predators that drill their prey then digest
the clam's adductor muscles until they pop open. The circular opening
at the top of the of skirt is where the snail's aperture sits; the
skirt is then produced around the shell; when done, the snail crawls
away. Dr. Michael S.