Assessment of the Hindlimb Membrane Musculature of Bats: Implications for Active Control of the Calcar

In this study, we investigate variation in the membrane and limb musculature associated with the calcar, a neomorphic skeletal structure found in the hindlimbs of most bats. We use diffusible iodine‐based contrast‐enhanced computed tomography and standard histological techniques to examine the calcars and hindlimb membranes of three bat species that vary ecologically (Myotis californicus, a slow‐flying insectivore; Molossus molossus, a fast‐flying insectivore; and Artibeus jamaicensis, a slow‐flying frugivore). We also assess the level of mineralization of the calcar at muscle attachment sites to better understand how muscle contraction may enable calcar function. We found that the arrangement of the calcar musculature varies among the three bat species, as does the pattern of mineral content within the calcar. M. molossus and M. californicus exhibit more complex calcar and calcar musculature morphologies than A. jamaicensis, and the degree of calcar mineralization decreases toward the tip of the calcar in all species. These results are consistent with the idea that the calcar may have a functional role in flight maneuverability. Anat Rec, 301:441–448, 2018. © 2018 Wiley Periodicals, Inc.
Source: The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology - Category: Molecular Biology Authors: Tags: Special Issue Article Source Type: research