Mustelus whitei was an extinct smooth-hound shark, belonging to a group of relatively small sharks that commonly forage over continental shelves and close to the seabed. Living smooth-hounds are active hunters of modest prey rather than large macropredators.

Its low-cusped teeth combined gripping and crushing functions, suggesting a diet rich in benthic invertebrates. Crustaceans were probably important, while molluscs, worms and small fishes are also plausible food sources. This feeding style would have allowed the shark to exploit abundant prey living on and within soft seafloor sediments.

The species is known from small teeth rather than complete skeletons, but their form gives a clear picture of a generalist benthic feeder. M. whitei adds another ecological layer to the London Clay fauna between tiny catsharks and the larger open-water predators.