Batoid locomotion
[1][2] Mobuliform swimming is common in pelagic Myliobatiformes species such as manta rays and is characterized by a flapping motion of the pectoral fins.
Batoids that utilize mobuliform swimming can be identified by their high aspect ratios, thicker pectoral fins that taper to a point and a lateral profile that resembles a hydrofoil.
[2] The pectoral fins of a mobuliform swimming ray experience a spanwise dorsoventral deformation that is highest at the tip and a chord-wise traveling wave.
Their rigid body gives them a high moment of inertia and their dorsoventrally flattened shape makes it difficult to maintain turns because they are unable to provide the lateral forces necessary to prevent slip.
They have a second set of pelvic fins called crura on the ventral side near the base of their tale that they use to in tandem to push along the substrate while their disk remains inactive.
From muscle fiber analysis it appears that punting may be a primary mode of transportation at low speeds (about 1/3 Body lengths per second) in some skates and rajiform locomotion may be used when for specific situations.
The distribution of pectoral thin thickness is such that rajiform swimmers benefit passively from hydrodynamic interaction between the substrate and their fins.
[12] The majority of electric rays have a distinctive style of low speed swimming that consists of periodically moving up in the water column then gliding back down.
Unlike Rajiformes and Myliobatiformes their propulsion comes solely from the movement of their caudal fin, which is much more developed than in skates and rays.
They have the potential to generate large thrust; this is what allows giant manta rays to completely clear the surface of the water.
[14] The variations in performance capabilities of each species lead to the development of a variety of different biomimetic automated underwater vehicles (BAUVs).
The complex actuation of the wings has been mimicked successfully through a variety of means including tensegrity structures, electroactive polymers, and fluid muscles.
