Phelps's Speedo featured V-shaped dermal denticles that are designed to mimic a shark's skin, thus allowing the water to move more efficiently.
The suit material mimics rough shark denticles to reduce drag in key areas and has a Turbulence Management System.
A crop-like dilatation of the gut and a recurved intestine, embedded in the compact yellowish-brown liver, the ducts of which open into it, form the rest of the digestive tract and occupy a large bulk of the visceral hump. The buccal region presents a pair of shelly jaws placed laterally upon the lips, and a wide range of variation in the form of the denticles of the lingual ribbon or radula.
Like other Euthyneura, they have very numerous small denticles on the lingual ribbon.