A Caltech Library Service

Phosphatic shell plate of the barnacle Ibla (Cirripedia): a bone-like structure

Lowenstam, Heinz A. and Weiner, Stephen (1992) Phosphatic shell plate of the barnacle Ibla (Cirripedia): a bone-like structure. Proceedings of the National Academy of Sciences of the United States of America, 89 (22). pp. 10573-10577. ISSN 0027-8424. PMCID PMC50383. doi:10.1073/pnas.89.22.10573.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The carbonate apatite crystals and the segmented structure of the shell plates of the barnacles in the genus Ibla distinguish them from the shell plates of all other barnacles, which are coherent calcitic structures. A detailed study of the hierarchical organization of one of the two shell plate types, the tergum, reveals a remarkably complex structure. Cylinders composed of a chitin-protein complex and nodes of plate-shaped crystals constitute the basic building blocks. The crystals are organized into layered stacks in which the c crystallographic axes are all aligned perpendicular to a 25-nm banded structure. The cylinders are, in turn, ordered in arrays such that parts of each cylinder are aligned in a plane, and parts form arcuate out-of-plane structures. The overall result is a lamellar structure, with a plywood-like motif, that is present throughout an individual segment. A series of segments forms an interlocking mineralized core, which is enclosed within a thick organic envelope. The flexible and complex skeletal structure of the tergum shows some marked similarities to the structure of lamellar bone. Although this is undoubtably a product of convergent evolution, the iblid tergum provides a unique perspective on bone structure, which was heretofore unavailable.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle CentralArticle
Additional Information:© 1992 National Academy of Sciences. Contributed by Heinz A. Lowenstam, August 11, 1992. We thank Mr. T. Arad (Weizmann Institute) for obtaining the TEM micrographs and Ms. J. Teshima (JEOL Research Laboratory, Palo Alto, CA) for the field emission SEM micrograph. We are grateful to Prof. Y. Achituv and Dr. G. Traeger (Bar Ilan University, Israel) for collecting live specimens of I. cumingi in Eilat. S.W. is the incumbent of the I. W. Abel Professorial Chair of Structural Biology. This work was partially funded by a Meyerhoff Fellowship, Weizmann Institute (to H.A.L.), the California Institute of Technology research fund for biomineralization (to H.A.L.), and Public Health Service Grant DE-06954 (to S.W.). The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Funding AgencyGrant Number
Meyerhoff FellowshipUNSPECIFIED
Weizmann InstituteUNSPECIFIED
Subject Keywords:biomineralization; carbonate apatite; organic matrix; crystals; plywood structure
Issue or Number:22
PubMed Central ID:PMC50383
Record Number:CaltechAUTHORS:20141215-154510089
Persistent URL:
Official Citation:H A Lowenstam and S Weiner Phosphatic shell plate of the barnacle Ibla (Cirripedia): a bone-like structure PNAS 1992 89 (22) 10573-10577
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:52830
Deposited By: Tony Diaz
Deposited On:15 Dec 2014 23:58
Last Modified:10 Nov 2021 19:44

Repository Staff Only: item control page