Blue sharks are light-bodied with long pectoral fins. Like many other sharks, blue sharks are countershaded: the top of the body is deep blue, lighter on the sides, and the underside is white. The male blue shark commonly grows to 1. 82 to 2. 82 m (6. 0 to 9. 3 ft) at maturity, whereas the larger females commonly grow to 2. 2 to 3. 3 m (7. 2 to 10. 8 ft) at maturity. Large specimens can grow to 3. 8 m (12 ft) long. Occasionally, an outsized blue shark is reported, with one widely printed claim of a length of 6. 1 m (20 ft), but no shark even approaching this size has been scientifically documented. The blue shark is fairly elongated and slender in build and typically weighs from 27 to 55 kg (60 to 121 lb) in males and from 93 to 182 kg (205 to 401 lb) in large females. Occasionally, a female in excess of 3 m (9. 8 ft) will weigh over 204 kg (450 lb). The heaviest reported weight for the species was 391 kg (862 lb). The blue shark is also ectothermic and it has a unique sense of smell.