Common dolphin
Delphinus delphis
Corey Husic
Key facts in one look
- Diet
- Fish; anchovy and sprat in the Black Sea
- Status in Georgia
- Native, Black Sea
- Size
- 1.9–2.5 m
- Habitat
- Open sea
- Family
- Delphinidae
- Conservation
- VU / LC (subspecies VU)
The common dolphin (Delphinus delphis) carries an hourglass-shaped patch on each flank: light grey, yellowish or golden in front and a dirty grey behind. The Black Sea has its own subspecies, D. d. ponticus, which is genetically distinct from Mediterranean and Atlantic dolphins. In 2011 about 6,000 common dolphins were counted in Georgian waters. They are numerous in spring and summer and often leap clear of the water, so they are relatively easy to watch. The species as a whole is Least Concern, but the Black Sea subspecies and the Georgian population are Vulnerable. It is no danger to people, but it genuinely needs protection.
Identification
Common dolphin: how to identify it
A medium-sized, supple dolphin with a dark back and a white belly. The best mark is the pale hourglass patch on the flank, whose front part may be yellowish or golden. The bottlenose dolphin is bigger, plain grey and has a short beak.
The back is dark and the belly white. Each flank carries an hourglass-shaped patch: light grey, yellowish or golden in front and a dirty grey behind. The patch shows best when the dolphin leaps out of the water.
Adults of the species are 1.9–2.5 m long and usually weigh 80–150 kg, some up to 235 kg. Males are generally larger than females. A newborn is 70–100 cm long and weighs about 10 kg. These are figures for the species as a whole, not separate measurements of Black Sea dolphins.
The bottlenose dolphin is the other dolphin in the Black Sea that you might confuse with it. It is bigger and bulkier, plain grey, with a short, well-defined beak. The common dolphin has the pale hourglass patch on its flank. If you can see that patch, you can be almost sure which one you are looking at.
It often travels in groups and leaps out of the water. In Georgian waters it often follows purse seiners. Each side of each jaw holds up to 50–60 small, sharp teeth, but you will not see them at sea: you recognise it by its colours and behaviour.
Colour
Swatches are illustrative. Do not identify a species by colour alone.
Often confused with
The common dolphin is an open-sea animal. In the Black Sea it lives farther offshore than the harbour porpoise and follows migrating schools of fish. Where anchovy and other fish are plentiful, there are more dolphins too. Below 150–200 m the Black Sea has no oxygen, so life is concentrated in the upper layer of water. In different seasons 6,000–16,000 common dolphins use Georgia's territorial waters. They are especially numerous in spring and summer. Our coast lies in the south-eastern Black Sea, where anchovy overwinters and dolphins find plenty of food.
It feeds on fish. In the Black Sea its main prey is anchovy and sprat, while the species as a whole eats many kinds of schooling fish and squid. Dolphins follow migrating fish schools, so their numbers in any part of the sea depend on the fish stock. In Georgian waters they often follow purse seiners and pick up fish that fall into the sea as the nets are hauled.
The common dolphin is a social animal. Across the species, groups of several hundred are common and split into subgroups of 20–30, and sometimes more than 10,000 dolphins gather. In Georgian waters it often leaps out of the water and follows purse seiners. Dives down to 200 m are known. Pregnancy lasts 10–11 months. In the Black Sea calves are weaned at 5–6 months and females give birth about once a year. These are the shortest intervals known for the species. Females mature at 2–7 years of age, males at 3–12.
In the 2008 IUCN assessment the Black Sea subspecies is Vulnerable (VU), and the provisional 2018–2021 reassessment keeps it at VU. The species as a whole is Least Concern (LC, 2025). In the 2021 assessment for Georgia's Red List it is Vulnerable (VU). That assessment rests on a decline of up to 30%, strandings, the 6,000–16,000 dolphins in Georgian waters and the genetic distinctness of the Black Sea population. Commercial dolphin hunting in the Black Sea was especially intense in 1929–1966. In 1966 the USSR, Bulgaria and Romania banned it, while in Turkish waters it continued until 1983. In Georgian waters the main threats today are disease, strong storms and the decline of its main prey species. Accidental capture in nets is rare here. In 2011 about 6,000 common dolphins were counted in Georgian waters, within a range of 1,500–21,000.
Related guides
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Yes. The Black Sea subspecies lives in Georgian waters. In 2011 about 6,000 dolphins were counted there, and in different seasons 6,000–16,000 dolphins use Georgia's territorial waters.
In spring and summer, when it is numerous in Georgian waters and often leaps out of the water. It often follows purse seiners to pick up fish that fall from the nets. It is an open-sea dolphin, so you are more likely to see it out at sea, away from the shore.
Look at the flank. The common dolphin has a pale, often yellowish hourglass patch there. The bottlenose dolphin is bigger and bulkier, plain grey and has a short beak.
Adults of the species are 1.9–2.5 m long and usually weigh 80–150 kg. Males are generally larger. A newborn is 70–100 cm long and weighs about 10 kg.
Fish. In the Black Sea mainly anchovy and sprat. It follows fish schools, so its numbers in any part of the sea depend on the fish stock.
No. The common dolphin is no danger to people. It does need protection, though, so do not chase it with a boat. If you find a stranded or injured dolphin on the shore, call 112.
Yes. In the 2021 assessment for Georgia's Red List it is Vulnerable (VU). The Black Sea subspecies is also Vulnerable on the IUCN list, while the species as a whole is Least Concern (LC). Dolphin hunting in the Black Sea was banned in stages from 1966.
References
What this profile is based on
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
Prepared by the Reptiles.ge editorial team from the sources listed here.
