Southern right whale dolphin (Lissodelphis peronei)
At first glace, the southern right whale dolphin may not appear to be a dolphin at all. It has a black top and a white underside, can grow to be as long as 10 feet, and is the only dolphin without any dorsal fin at all. Its sleek look led it to be referred to as a ‘sea snake’ for a long time. Preferring frigid waters, the southern right whale dolphin can only be found in the sub Antarctic zones, but will occasionally venture as far north as New Zealand or the southernmost point of South America. They often are spotted with hourglass dolphins, despite not being part of the same genus. Their distribution in uninhabited areas has made the species challenging to count, forcing the IUCN to label it as data-deficient.