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Sharks have a fairly simple muscle structure. The majority of the musculature is made up of huge, striated, segmented, V-shaped muscle groups termed myotomes, which are easily visible in a skinned shark. The exceptions to this rule are specific muscles that govern the jaws and particular fins. A connective tissue-based myoseptum divides individual myotomes from one another. Additionally, a horizontal septum divides them into dorsal and ventral groupings.