The whale shark's markings could be a result of its evolutionary relationship with bottom dwelling carpet sharks. Distinctive markings in a pelagic species could be linked to social activities such as postural displays and recognition processes. Another possibility is that these pigment patterns could be an adaptation for radiation shielding, important in a species that may spend a significant proportion of time in surface waters possibly exposed to high levels of ultraviolet radiation. The teeth are minute, about 300 rows in each jaw. An individual tooth has a single, hooked cusp.
Teeth appear to play no role in feeding.
It would appear that the denticles are hydrodynamically important in its pelagic lifestyle. The whale shark is the largest living fish. Maximum size is thought to be 20m. Sexual maturity in both sexes may not occur until the sharks are over 9m in length. Age estimates for whale sharks are as high as 60 years, but no one really knows how long this species lives.