JMZ: staining E. coqui; investigating development; dissection of all adults; main writer; RD: discussion, manuscript.
Cranial muscle development in frogs with different developmental modes: Direct development versus biphasic development
Version of Record online: 3 DEC 2013
Copyright © 2013 Wiley Periodicals, Inc.
Journal of Morphology
Volume 275, Issue 4, pages 398–413, April 2014
How to Cite
Ziermann, J. M. and Diogo, R. (2014), Cranial muscle development in frogs with different developmental modes: Direct development versus biphasic development. J. Morphol., 275: 398–413. doi: 10.1002/jmor.20223
- Issue online: 6 MAR 2014
- Version of Record online: 3 DEC 2013
- Manuscript Accepted: 3 OCT 2013
- Manuscript Revised: 30 SEP 2013
- Manuscript Received: 17 JUN 2013
- Howard University College of Medicine (Rui Diogo's start-up package)
- direct development;
- cranial muscles;
Normal development in anurans includes a free swimming larva that goes through metamorphosis to develop into the adult frog. We have investigated cranial muscle development and adult cranial muscle morphology in three different anuran species. Xenopus laevis is obligate aquatic throughout lifetime, Rana (Lithobates) pipiens has an aquatic larvae and a terrestrial adult form, and Eleutherodactylus coqui has direct developing juveniles that hatch from eggs deposited on leaves (terrestrial). The adult morphology shows hardly any differences between the investigated species. Cranial muscle development of E. coqui shows many similarities and only few differences to the development of Rana (Lithobates) and Xenopus. The differences are missing muscles of the branchial arches (which disappear during metamorphosis of biphasic anurans) and a few heterochronic changes. The development of the mandibular arch (adductor mandibulae) and hyoid arch (depressor mandibulae) muscles is similar to that observed in Xenopus and Rana (Lithobates), although the first appearance of these muscles displays a midmetamorphic pattern in E. coqui. We show that the mix of characters observed in E. coqui indicates that the larval stage is not completely lost even without a free swimming larval stage. Cryptic metamorphosis is the process in which morphological changes in the larva/embryo take place that are not as obvious as in normal metamorphosing anurans with a clear biphasic lifestyle. During cryptic metamorphosis, a normal adult frog develops, indicating that the majority of developmental mechanisms towards the functional adult cranial muscles are preserved. J. Morphol. 275:398–413, 2014. © 2013 Wiley Periodicals, Inc.