The minke whale is the smallest of the baleen whales found in UK waters, measuring 7 to 10 metres when fully grown. Females are usually slightly longer than males. The body of a minke whale is slender and very streamlined; the head is narrow and pointed. The small dorsal fin is usually strongly falcate (curved) and is a unique feature used to identify individual animals in the Hebrides. It is positioned about two-thirds of the way down the back and is visible at the same time as the blowhole when the animal surfaces. The blow is not normally visible at sea. The dorsal fin and back are dark grey or black, the belly is bright white and there is a distinctive white band on the upper side of each pectoral (side) fin. Lifespan is estimated at around 40 to 50 years.