There are more than 40 known species of dolphins – each with unique characteristics that set them apart and make them fascinating to study and observe. Dolphins as a whole represent a diverse group of marine creatures with varying behaviours, diets, and ways of interacting with their environments. Here are the top 10 most common you’ll likely encounter:
1. Common Dolphin (Delphinus delphis)
The common dolphin is characterized by its size (2-2.7m long), distinctive hourglass pattern on the sides, and dorsal fin in the middle of the back. They’re widely distributed in warm, tropical oceans around the world and are known for their playful behaviour and high-speed swimming.
2. Bottlenose Dolphin (Tursiops truncatus)
The bottlenose dolphin is probably the most recognized dolphin species due to their frequent appearances in aquarium shows and TV shows. They are medium-sized (2-4m long) with a robust, streamlined body, a prominent and short beak, and a tall, curved dorsal fin. They inhabit a variety of marine environments from the Atlantic and Pacific Oceans to the Mediterranean and Black Sea.
3. Spinner Dolphin (Stenella longirostris)
Spinner dolphins are famous for their acrobatic displays as they leap and spin out of the water. They are slender in build and have long, thin beaks. Their colouration varies but usually includes three shades: dark grey on the back, light grey on the flanks, and white on the belly. These dolphins inhabit tropical and subtropical oceans worldwide.
4. Orca or Killer Whale (Orcinus orca)
Despite their name, killer whales are actually the largest species of dolphin. They are notable for their striking black and white colouration, and males have a tall, prominent dorsal fin that can reach up to 1.8 meters in height. Orca pods have been spotted in oceans all over the world, from the cold waters of Antarctica and the Arctic to warmer, tropical seas.
5. Amazon River Dolphin or Boto (Inia geoffrensis)
The Amazon river dolphin, also known as the pink dolphin due to its distinctive pinkish hue, is one of the few species of dolphins that live in freshwater environments. They have a bulging foreheads, long snouts filled with sharp teeth, and small eyes, as visibility in their environment is poor. As the name implies, they’re found in the freshwater systems of the Amazon and Orinoco Rivers in South America.
6. Risso’s Dolphin (Grampus griseus)
Risso’s dolphins are robust with a blunt head, no discernable beak, and a tall, falcate (hooked) dorsal fin. Their bodies are covered in scratch marks, which are caused by social interaction. They inhabit temperate and tropical oceans worldwide, with notable populations in the Mediterranean Sea and around the Azores.
7. Dusky Dolphin (Lagenorhynchus obscurus)
The dusky dolphin, known for its acrobatic behaviour and strikingly patterned body, is relatively small, measuring about 1.6-2 meters. Their back is dark grey, their belly is white, and they have a two-tone dorsal fin. They inhabit coastal waters in the Southern Hemisphere, particularly off the coasts of New Zealand, South Africa, and South America.
