The Open Anatomy Journal


ISSN: 1877-6094 ― Volume 6, 2014

Encephalization and Brain Organization of Mobulid Rays (Myliobatiformes, Elasmobranchii) with Ecological Perspectives

Csilla Ari*, 1, 2, 3
1 USF Health Byrd Alzheimer`s Center and Research Institute, Tampa, Florida 33613, USA
2 Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612, USA
3 Semmelweis University, Department of Anatomy, Histology and Embryology, Budapest 1094, Hungary


In the present study the brain mass to body mass ratio and external morphological features of the brain of Mobula japanica, Mobula thurstoni and Manta birostris (devilrays) are described. The Mobulids extended the upper boundary of the minimum convex polygon described earlier by other authors for batoids, which is plotted on a double logarithmic scale of brain to body mass, causing some change in the allometric coefficient. The encephalization quotient of Mobulas was higher than unity, therefore it can be concluded that the actual brain mass is greater than expected by the given body mass. M. japanica had the highest percentage (61%) of telencephalic mass from all batoids, while the brain mass of M. birostris was the highest of all fish studied so far. The gross morphology of the enlarged Mobulid telencephalon and cerebellum prominently resembled to that of Sphyrna mokarran (great hammerhead shark). A structural dimorphism of the highly foliated cerebellum was detected between genders of the M. japanica, albeit with a small sample size. No such gender-related dimorphism was detected in brain mass/body mass ratio. Other brain parts were similar to those of other elasmobranch species. The data are discussed in terms of their ecological and evolutionary significance

Keywords: Cartilaginous fish, devil ray, morphometry, cerebellum, sexual dimorphism, neuroecology.

Identifiers and Pagination:

Year: 2011
Volume: 3
First Page: 1
Last Page: 13
Publisher Id: TOANATJ-3-1
DOI: 10.2174/1877609401103010001

Article History:

Received Date: 10/2/2011
Revision Received Date: 12/2/2011
Acceptance Date: 14/2/2011
Electronic publication date: 6/5/2011
Collection year: 2011

Article Information:

© Csilla Ari,Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the USF Health Byrd Alzheimer`s Center and Research Institute, Tampa, Florida 33613, USA, Tel: +1-813-3960606/60712, Fax: +1-813-8661601, E-mail:

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