DOLPHINS OF A DIFFERENT COLOUR • Lagenorhynchus obscurus • the dusky dolphin who turned ebony •

Dark dusky dolphins like these have been seen a few times around New Zealand. They show a form of melanism: an abnormal deposit of melanin in the skin, often – but not always – resulting in a darker animal. This can take on many forms, such as increasing the spread of dark markings (like a tiger with merged stripes, which is sometimes called ‘abundism’). However in these duskies the markings remain intact but so much melanin is produced all over the body that they become harder to make out. They also appear more brownish than their normally coloured counterparts, possibly indicating an increase in pheomelanin (brown pigment) production.

– Watercolour on hot-pressed paper, 14.8 x 21 cm (original available).