pen shell

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pen shell

n.
Any of several large marine bivalve mollusks of the family Pinnidae, having a thin wedge-shaped or fan-shaped shell.

[From the resemblance of their shells to quill pens .]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
Extreme pH conditions at a natural C02 vent system (Italy) affect growth, and survival of juvenile pen shells (Pinna nobilis).
Relative growth rates of the noble pen shell Pinna nobilis throughout ontogeny around the Balearic Islands (Western Mediterranean, Spain).
There are giant clam shells (Tridacna gigas) from Palawan province and amber pen shells (Pinna carnea) from Sorsogon.
In these flats, cowries, cones, mitres, turrids, bubble shells, pen shells, cockles and scallops all living in close proximity and even the most delicate shells may survive intact.
Tokyo, Japan, June 6, 2006 - (JCN) - The Fisheries Research Agency (FRA) has undertaken a research project of pen shells, a kind of clam dwelling in Ariake Sea.
Stretching along the gulf north of town, these white sand beaches hold the greatest variety and quantity of discoveries we found: scallop-edged yellow cockles, wing-shaped zebra arks, nearly translucent fig shells, fighting conches, stubby branched sponge's, sea stars, stiff pen shells, pear whelks, lightning whelks, and the papery spirals of their egg cases.
At each sampling, adult pen shells were collected at two depths of residence along the intertidal zone (<1 m and 5-8 m), to assess if the time of aerial exposure affected reproductive and larval performance.
Joseph Bay sites were composed of shellfish beds (mussels, clams, and pen shells) interspersed within the seagrass beds.
The pen shells of the family Pinnidae are commercially important in a number of Indo-Pacific countries.
The data of the length width relationship (log transformed) of the pen shells of Mallorca indicate possible breakpoints from juvenile through adult stages (Fig.
In an attempt to restore the stock abundance of the pen shells, efforts are currently under way to establish new techniques for seed production and thus prevent the reduction of natural stocks.
In our system for RAPD amplification of the four forms of pen shells, we adopted the conditions at the raised annealing temperature of 39[degrees]C, which is higher than in other systems and amplified abundant and reproducible band patterns.