Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: A case study on homology versus analogy
Article first published online: 8 MAY 2014
© 2014 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 322, Issue 5, pages 269–280, July 2014
How to Cite
2014. Male claspers in clam shrimps (Crustacea, Branchiopoda) in the light of evolution: A case study on homology versus analogy. J. Exp. Zool. (Mol. Dev. Evol.) 322B:269–280., , , , .
- Issue published online: 9 JUN 2014
- Article first published online: 8 MAY 2014
- Manuscript Accepted: 15 APR 2014
- Manuscript Revised: 5 APR 2014
- Manuscript Received: 19 AUG 2013
Male “clam shrimps” possess highly modified first (and second) trunk limbs for clasping the carapace of females during copulation. Claspers are present in all three clam shrimp taxa (Laevicaudata, Spinicaudata, and Cyclestherida) but despite striking similarities in their morphology and function, the matter of their homology is controversial. In this study, we address the question of the homology and evolution of these structures by comparing the developmental transformation of an unspecialized trunk limb into a clasper. In addition, we study the musculature and the nervous system in trunk limbs and claspers using confocal laser scanning microscopy. We establish that most (but not all) of the various parts of the claspers are homologous between clam shrimp taxa. We suggest that a single pair of claspers was already present in the ground pattern of Diplostraca, probably most comparable to those in Cyclestherida. The claspers, therefore, do not represent a case of analogy. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 269–280, 2014. © 2014 Wiley Periodicals, Inc.