Our principal investigator, Dr. Csilla Ari performed anatomical and histological examinations on the brain of several shark and ray species as well as of a sawfish and chimaera species. During her study the astroglial cell (which function are e.g. participate in nervous system repair, maintanance of blood-brain barrier, provide metabolic support for neurons) distribution was described of the above species applying immunohistochemical methods. The research has been recently published as a book (See publications).
Based on the results of this research we will attempt to predict behavioral patterns of certain cartilaginous fish species, including devil rays.
During her studies, Dr. Csilla Ari discovered that Mobulid rays have the largest brains compared to their bodyweight among batoids (skates and rays), and some of the brain parts suggests well-developed sensory abilities.
Behavioral research on captive Manta rays
A worldwide unique research experiment was designed by our principal investigator, Dr. Csilla Ari to study the learning and sensory abilities of the only captive Manta birostris (giant devil ray) available in Europe, in the Lisbon Aquarium. Studying this species in the wild and to keep them in captivity are both difficult tasks, so very little scientific information is known on their basic biology and abilities. However, we hope that with the help of our research we can give some insight into the behavior of this mysterious creature. (See publications)
An other research project focused on the fin movement of the captive Manta birostris (giant devil ray) and a special three dimensional recording system was used to revail hidrodinamical characteristics. The analyses of their efficient fin movement can lead to hidrodinamical innovations, and could also be used to determine the condition of these animals. (See publications)
Behavioral research on wild Manta rays
There are certain behavioral aspects of these magnificent creatures which can be observed easily by diving with manta rays at many popular dive sites around the world.
These behaviors are for example:
In plankton dense water they enhance their feeding effectiveness by barrell-rolling in the water coloumn with wide open mouth.
Manta rays sometimes spend more hours on cleaning stations each day, where they let cleaner fish to eat their parasites from their body surfaces, gills and to remove dead skin.
Usually a larger female is followed or chased by one or more males, sometimes for a few hours, sometimes for more days creating a so-called „mating-train” before the actual mating occurs. (Yano, K., Sato, F., Takahashi, T. (1999). Observations of mating behavior of the manta ray, Manta birostris, at the Ogasawara Islands, Japanese Ichthyological Research 46(3):289-296.)
More details on behavioral research will be presented soon.