prismatic layer

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prismatic layer

the middle layer of the three layers forming the shell of MOLLUSCS.
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These prismatic layers are always found on the external surface of the shell, with individual prisms arranged nearly perpendicular to the shell surface and surrounded by organic envelopes (also called organic walls).
In the pectinoids and ostreids, the transition between the prismatic layers and the foliated layer is marked by the interruption of the organic envelopes at the end of the prisms, but the mineral matter is continuous across layers.
The groups that have retained flexible prismatic layers in both valves (e.
This event has no doubt contributed to the evolutionary success of the group, since those groups that carried out this replacement have undergone a pronounced diversification over time, whereas those that retained the prismatic layers in both valves are clearly less diversified.
Organic components of prismatic layers in molluscan shells.
Early bivalves built wholly aragonitic shells consisting of an external prismatic layer and middle and inner nacreous layers (Taylor, 1973).
1] in both nacreous and prismatic layers was assigned to HC[O.
Studies have shown that nacrein, a 60 kDa protein isolated from the EDTA-soluble organic matrix of both nacreous and prismatic layers of Pinctada maxima, exhibits carbonic anhydrase activity (CA), suggesting that carbonic anhydrase acts to catalyze HC[O.
The majority of the calcite forms the prismatic layer of the shell.
The family of proteins from the prismatic layer induced a habit modification in calcite growth, yielding globular growth instead of the rhombohedra obtained in the absence of proteins.
In the in vitro crystallization experiment, the soluble matrix from the nacreous layer induced the formation of aragonite, whereas the soluble matrix from the prismatic layer induced the deposition of calcite.
Identical carbonic anhydrase contributes to nacreous or prismatic layer formation in Pinctada fucata (Mollusca: Bivalvia).