Body shape and other structural and physical traits.
Explanation:
The morphological species concept defines species on the basis of body shape, size, color, and other structural traits. The morphological species concept is applicable to both sexual and asexual organisms and does not depends on gene flow between the populations. It defines species on the basis of easily measurable features about the appearance of the organisms.
It could possibly cause a deformation or oddity in the muscle. It is unlikely that this would be visible but it could cause many issues in the tissue of said muscle.
