The Journal of Foraminiferal Research; January 2009; v. 39; no. 1;
p. 8-14; DOI: 10.2113/gsjfr.39.1.8
© 2009 Cushman Foundation for Foraminiferal Research
ASYNCHRONOUS CALCIFICATION IN JUVENILE MEGALOSPHERES: AN ONTOGENETIC WINDOW INTO THE LIFE CYCLE AND POLYMORPHISM OF PENEROPLIS
Martin R. Langer1,3,
Walid A. Makled1,
Stephanie J. Pietsch2 and
Anna Weinmann1
1 Steinmann Institut für Geologie, Mineralogie und Paläontologie, Rheinische Friedrich Wilhelms Universität, Nussallee 8, 53115 Bonn, Germany.
2 Zoologisches Forschungsmuseum Alexander Koenig, Museumsmeile Bonn, Adenauerallee 160, 53113 Bonn, Germany.
3 Correspondence author. E-mail: martin.langer{at}uni-bonn.de
Fully calcified megalospheric juveniles were found to be closely packed within a brood chamber of the larger symbiont-bearing foraminifer Peneroplis sp. (dOrbigny) from Chuuk Island (Micronesia). The juveniles exhibit a notable variation in size of the proloculi and various forms of test deformations. Both the size variation of the megalospheric proloculi and the test deformations are indicative of asynchronous calcification and are a potential source of natural polymorphism in Peneroplis. The results of this study have implications for the interpretation of abnormal shell forms as bioindicators and place constraints on the classic definition of three size classes in Peneroplis.
Copyright © 2009 by Cushman Foundation for Foraminiferal Research