Angel Wing Shells and Piddock Shells of the Pholadidae Family
Two Angle Wing Shells and Piddock Shells of the Pholadidae Family can be found in this website:
Phylogeny: Angel Wings and Piddock Shells of the Pholadidae Family (Lamarck, 1809), are bivalve mollusks in the Myida Order. Shells in this order may be freshwater or marine species, which burrow and have well-developed siphons. They generally are soft-shelled and lack a nacreous layer. Pholadidae is one of three families in the superfamily Pholadoidea. The Pholadidae family consists of twenty-three genera and one hundred forty-one species, which have been placed in four subfamilies – the Jouannetiinae that has two genera and twelve species, the Martesiinae that has eight genera and thirty-seven species, the Pholadinae that has six genera and thirty species, and the Xylophagaidae that has seven genera and sixty-two species. These shells are also commonly called Boring Clams or Pholadids.
Description: Pholadidae Shells are equivalve, slightly inflated, fragile, and thin. They are composed of aragonite. They may have either an elongated, globular oval or quadrate profile. They have exterior sculpting that varies between species and by section of an individual. They are divided into two or three sections by different texture. The sculpting includes reticulated (net-like), spiny, and imbricated (overlapping plates) concentric ridges. This sculpting allows the shells to mechanically abrade the substrate in which they reside. The living animals in most family members do not fit within the shell. The hinge (which lacks teeth), the muscular attachments, and other aspects of the shell are modified to allow it to move in a circular, rasping motion to facilitate burrowing. Angel Wings are white to brownish in color and some are bio-luminescent. Angel Wing Shells can reach a maximum of 18 cm (7.1 inches) in length and 4.7 cm (1.8 inches) in height.
Habitat and Distribution: Because the living animals of the Pholadidae Family their members do not fit within their shell, they burrow into clay, coral, mud, rock, shale, shells and wood for protection. They are found intertidally, and at depths up to 300 m (984 feet) but the majority are found in water that is less than 100 m (328 feet) deep. Shells in the Pholadidae Family are found globally in temperate and tropical seas. About one dozen species in this family are found in Mexican Waters.
Natural History: Pholadidae Shells spend their entire adult life within their burrow, which may be up to one meter in length. They utilize their extended siphon to feed on suspended plankton and other organic matter. In turn they are preyed upon by crabs and gastropods. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. These shells have been an important food source in some locations for thousands of years. Because of their boring activity, some species cause significant damage to the wood and rock infrastructure of harbors.