Chilean dolphin Cephalorhynchus eutropia (Gray, 1846)

Chilean dolphins are endemic to the shallow, nearshore waters of south-central Chile. They are small bodied and robust delphinids with distinctly rounded dorsal fins and no distinct beak. Body coloration is composed of shades of gray with two white patches on the ventral side separated by a gray thoracic band. Genetic and morphological evidence suggests that Chilean dolphins along the northern open coast form a distinct population compared to those in Chilean Patagonia and the southern fjords. Chilean dolphins usually occur in small groups but can form larger aggregations, particularly along the open coast. Chilean dolphins are agile swimmers often found in the surf zone of the open coast from Valparaiso to Maudlin, and in tidal rips and channels in the southern fjords. They have a strong association with rivers mouths and estuaries, including entering rivers and glacial lagoons. Overall abundance is not known but only a few thousand dolphins are estimated to inhabit northern Patagonia spread across multiple small sub-populations numbering 40–100 individuals. Their nearshore habitat overlaps with human developments and nearshore gillnet fishing along the open coast, and with intensive aquaculture farming in the fjords. Although mortality in gillnets and antipredator nets of fishfarms currently constitutes the main threats, habitat degradation, climate change, infectious diseases and increasing vessel traffic are likely to add further pressures on small, and possibly fragmented sub-populations.