A dolphin with contrasting patches along its sides that form an hourglass-like pattern.
The sides are yellowish tan ahead of the dorsal fin and pale gray behind it. Young animals may have paler markings.
Common dolphins along Portugal’s coast were encountered in groups ranging from about twenty to several hundred animals.
A 2017 study investigated kinship using 204 skin samples collected in 2007–2009. Researchers sampled adult-sized dolphins, avoiding animals accompanied by calves, and compared fifteen DNA markers to infer parent–offspring, sibling and other relationships.
Close relatives were sampled in different encounter groups, whereas fourteen pairs related at the cousin level were sampled together. Most relatives were sampled in different years. One dolphin was sampled twice at the same locality in different years. These samples revealed links across time and place as well as companions encountered together.
An extinction-risk assessment has not been added yet.
Accidental capture in fishing gear is a conservation issue for common dolphins in the Bay of Biscay. From 22 January to 20 February 2025, fishing was temporarily closed for vessels longer than eight metres using high-risk gear. PELAGIS estimated about 1,900 common-dolphin bycatch deaths across the Bay of Biscay and western English Channel from December 2024 to March 2025, using strandings and information about carcass drift. These are regional mitigation and mortality-monitoring efforts.