Common dolphin

Latin: Delphinus delphis

Manx: Lheimmeyder cadjin giare-ghobbagh

IUCN Red List status: Least Concern

Physical description

The common dolphin is a small, streamlined species with a body length of 2.5 metres (8ft).

Common dolphins have a distinctive yellow and grey hourglass pattern on the flanks and the back is dark grey or brownish. The beak is pointed and a black stripe runs from beak to eye. The dorsal fin is sickle shaped, fairly tall, and centrally located. A yellow patch may be visible in the middle of the dorsal fin.

Manx distribution

Typically present in Manx waters from June to September on the west and south west of the island. However, seasonality has increased in recent years. Between 2007 and 2020, the common dolphin was considered the ‘least common’ dolphin species in Manx waters, with an average of just seven reports in one year and pods containing no more than 25-30 individuals.

The species has been making a comeback since 2020 and numbers are increasing across the whole of the west of Britain and the Isle of Man. It is now possible to see pods up to or exceeding 200 individuals in late summer. These pods usually include young calves and juveniles, and sexual behaviour has been observed within these pods.

Worldwide distribution

This species is abundant worldwide and can be found in temperate and tropical waters. Super-pods of thousands of common dolphins can be seen in some locations such as California and South Africa.

Due to their small size, common dolphins are frequently susceptible to being by-caught by huge super trawlers. An estimated 9,000 common dolphins die annually in the Bay of Biscay alone as a direct result of this large scale fishery.

Common dolphins were previously thought to be split in to two species, the short-beaked and long-beaked, but they are now all considered one species. There are two long-beaked variants in the eastern north Pacific and the Indian ocean which are recognised as subspecies.

Photo by Kirrie Jenkins
Behaviour

Common dolphins are one of the fastest species of dolphin, reaching 37mph. They are streamlined and agile, often seen bow-riding vessels. They swim at such a pace that they produce lots of disturbance and white water, in a behaviour known as porpoising.

Feeding

Common dolphins have a varied diet, mainly feeding on small schooling fish such as herring and mackerel. 

Photo by Jane Young

Report a Sighting

Have you seen a common dolphin in Manx waters? Report your sighting to us.