Stiff Pen Shell (Atrina rigida)

Hardened Pen Shell (Atrina rigida) The hardened pen shell, or unbending pen shell, is one of the few types of pen shells. These mollusks have a long, triangular, or wedge-molded shell and join to rocks or shells in sandy, shallow sea bottoms. Portrayal Hardened pen shells can be up to 12 long and 6.5 wide. They are an earthy colored or purplish-earthy colored shading and have at least 15 emanating ribs that fan out over the shell. They may likewise have erect, cylindrical spines. Pen shells may deliver dark pearls. Grouping Realm: AnimaliaPhylum: MolluscaClass: BivalviaOrder: PterioidaFamily: PinnidaeGenus: AtrinaSpecies: rigida Natural surroundings and Distribution Firm pen shells live in hotter water from North Carolina to Florida, and furthermore in the Bahamas and West Indies. They are found on sandy bottoms in shallow water. They join with their byssal strings, pointed end down. Taking care of Pen shells are channel feeders and eat little particles going through the water. Preservation and Human Uses Pen shells have a scallop-like adductor muscle (the muscle that opens and shuts the shells) and are eatable. They additionally produce dark pearls which might be utilized in gems. Pen shells in the (Mediterranean pen shells) were collected for their byssal strings, which were woven into a costly material. Sources Gofas, S. 2011. Pinnidae. World Register of Marine Species (Online) Accessed on May 24, 2011Meinkoth, N.A. 1981. National Audubon Society Field Guide to North American Seashore Creatures. Alfred A. Knopf, New YorkScott, S. 2011. Pen Shells Provided Ancients Byssal Threads for Fine Sea Silk (Online) Accessed May 24, 2011