White-beaked Dolphin Lagenorhynchus albirostris
Not all white-beaked dolphins have a white beak. Their predominant colouration is black with lighter grey and white swathes along the flanks and their belly, cheeks and throat are also white. The dorsal fin of a white-beaked dolphin is larger than you might expect and the flippers are broad and pointed and almost 20% of the total body length. Image: Natural England/Rebecca Walker (Flickr).
Find out more: Whale and Dolphin Conservation, The Mammal Society, iNaturalist