Pacific white-sided dolphin

The Pacific white-sided dolphin (Aethalodelphis obliquidens), also called the hookfin porpoise, is an active oceanic dolphin of the cool and temperate waters of the North Pacific Ocean. Its range arcs from the Baja California Peninsula on the eastern side to the South China Sea on the western side, with populations in the Sea of Japan, the Sea of Okhotsk and the southern Bering Sea, and it prefers deep offshore water through the year. Adults have a dark gray back, beak, flippers and dorsal fin, a creamy white chin, throat and belly, and light gray patches and a pale stripe along each flank. Males reach about 2.5 metres and 200 kilograms and females about 2.3 metres and 150 kilograms. The species eats hake, anchovies, squid, herring, salmon and cod, travels in groups that average about 90 animals and sometimes exceed 300, and readily rides the bow waves of boats. It was traditionally placed in the genus Lagenorhynchus, and in 2025 it was reclassified with the dusky dolphin into the genus Aethalodelphis.