Rough-toothed dolphins are found throughout the world in tropical and warmer temperate waters. These small members of the dolphin family usually travel in small, tight-knit groups of two to 20 individuals. Their common name was based on the ridges found on their teeth, which are unique to this species.

Rough-toothed dolphins can remain underwater for up to 15 minutes. They can also adapt well to captivity, which is unusual for oceanic dolphins

Rough-toothed dolphins are relatively small compared to other dolphins. They can reach up to 8.5 feet in length and weigh about 350 pounds. They have a small head with a long rostrum and no demarcation between their gently sloping melon (or forehead) and rostrum. Their dorsal fin and pectoral fins or flippers are distinctively large, which is characteristic of this species. They have a “reptilian” appearance that is also distinct and unique among dolphins.

Rough-toothed dolphins have dark gray bodies with a white throat and “lips.” They also have a narrow dark cape that runs down their back between the blowhole and dorsal fin. Their underside usually has some white or lighter spots or blotches.

Rough-toothed dolphins are usually found in tight-knit groups of approximately 10 to 20 individuals. However in Hawaii, they are found in smaller groups of on average three individuals and a median group size of seven; they are rarely observed in larger groups of up to 100 individuals. They often associate with other cetacean species, including short-finned pilot whales, bottlenose dolphins, pantropical spotted dolphins, and spinner dolphins. They eat squid and different types of fish.

It’s dark grey in color and like the Pilot Whale, also is not a whale and is in fact a dolphin. All dolphins are actually whales, but not all whales are dolphins. They get their name from the similarities between the skulls and teeth of the Orca and the False Killer Whale.

The False Killer Whale is the most social of all the whales, going as far as to share prey with one another and, if you’re lucky, they’ll offer food to boaters and divers as well. They’re found usually around the Northwestern Islands year-round.

Short-finned pilot whales are found globally in tropical and temperate oceans. They are one of two species of pilot whale, along with the long-finned pilot whale. The two species differ slightly in size, features, coloration, and pattern. In the field and at sea, it is very difficult to tell the difference between the two species.

Short-finned pilot whales are long-lived, slow to reproduce, and highly social. They live in stable groups of 15 to 30 animals composed of close family relatives, and tend to live in localized, resident populations, although some populations have wider ranges. Their diet consists primarily of squid, with a small amount of fish. They are commonly found along the coast close to the continental shelf, although some populations have been found to extend into deep, open ocean environments such as in the eastern tropical Pacific Ocean. Pilot whales are often involved in mass strandings for reasons that are still unclear.

Three stocks of short-finned pilot whales are recognized in U.S. waters, which live along the U.S. east and west coasts, and around the Hawaiian Islands. On the west coast, short-finned pilot whales were once commonly seen, with an apparently resident population around Santa Catalina Island. After a strong El Niño in 1982 and 1983, short-finned pilot whales virtually disappeared from this area, and there are now thought to be about 800 animals in the West Coast stock. About 23,500 animals comprise the East Coast stock, around 2,000 in the Gulf of Mexico stock, and about 9,000 animals in the Hawaiian stock.

The oldest estimated age of false killer whales (based on growth layers in teeth) is 63 years for females and 58 years for males.

Female false killer whales reach sexual maturity between the ages of 8 and 11, while males mature 8 to 10 years later. Gestation ranges from 11 to 16 months, and lactation occurs for 1.5 to 2 years. Time between births is unknown but is estimated to be around 7 years. Female false killer whales enter menopause and become less reproductively successful between 44 and 55 years old.

The color pattern on this dolphin is unusual for a dolphin. Their back is a dark grey ranging to black with a white underbelly and they have a light grey, yellow, or gold hourglass pattern on both their sides. They’re found year-round and are rarer than many of these other species as they’re much shyer of boats and people.

Short-beaked common dolphins are usually found in large social groups averaging hundreds of individuals and are occasionally seen in larger groups—known as mega-pods—consisting of thousands of animals (up to 10,000 individuals). These large groups are thought to consist of sub-groups of 20 to 30 individuals that are possibly related or separated by age and/or sex.

Short-beaked common dolphins are often active at the surface. These highly social, energetic dolphins commonly leap out of the water at high speeds, flip end-over-end, and somersault in the air. They will also swim alongside ships riding the bow for long periods of time. This “bow riding” behavior has even been observed alongside large whales.

Short-beaked common dolphins usually rest during the day and feed at night. They can dive to approximately 1,000 feet but typically dive to about 100 feet to feed on schooling fish and cephalopods (e.g., squid) that migrate towards the surface at night. Short-beaked common dolphins associate with schools of tuna and seabird-feeding flocks, especially in the eastern tropical Pacific Ocean. They have also been observed in mixed groups with spinner dolphins and striped dolphins.

Short-beaked common dolphins have an estimated lifespan of up to 35 years. On average, males become sexually mature at 10 years and females at 8 years, although individuals may become sexually mature between 5 and 12 years. Off the California coast, calving takes place during the winter months after a 10- to 11-month gestation period, whereas calving takes place year-round in the eastern tropical Pacific Ocean. Every 2 to 3 years, adult females give birth to a single calf that is about 2.5 to 3 feet long. Calves begin to wean after about 1 year, but remain dependent on their mother for another year or more.

The dolphins in the Pacific near the Hawaiian islands are unique in that they display migration patterns that others in other regions don’t. This means that the best time to see this more elusive dolphin is around the islands during the late Spring and Summer months.

Striped dolphins are usually found in tight, cohesive groups averaging between 25 and 100 individuals, but they have occasionally been seen in larger groups of up to several hundred and even thousands of animals. Within these groups, there is a complex system of individuals that may be organized by age, sex, and breeding status. Striped dolphins rarely associate with other species of whales, dolphins, and seabirds.

Their surface behavior is often characterized as sociable, athletic, energetic, active, and nimble with rapid swimming. They can often be observed breaching, roto-tailing (a circular motion using the tail while jumping out of the water), jumping, and leaping 20 feet above the surface. In the eastern tropical Pacific Ocean, field biologists and fishermen call striped dolphins “streakers” because they avoid vessels by rapidly swimming away.

Striped dolphins feed throughout the water column on a diverse diet of fish and cephalopods (e.g., squid and octopus). They are capable of diving to at least 2,300 feet.

Striped dolphins prefer tropical to warm temperate waters (52 to 84° F) that are oceanic and deep. They are mainly found in waters seaward of the continental shelf from 50° North to 40° South and are often linked to upwelling areas and convergence zones.

Striped dolphins are found worldwide. Their range includes waters off Greenland, northern Europe (United Kingdom, Denmark), the Mediterranean Sea, Japan, Argentina, South Africa, western Australia, and New Zealand.

In the United States, they can be found off the west coast, in the northwestern Atlantic, and in the Gulf of Mexico. They also live in the waters off Hawai‘i, but do not live in the colder temperate and boreal waters of Alaska. This species has been documented outside its normal range in areas such as the Faroe Islands, Denmark’ southern Greenland; the Kamchatka Peninsula, Russia; and Prince Edward Island, Canada.

The estimated lifespan of striped dolphins is up to 58 years. They become sexually mature when they reach about 7 feet in length—between the ages of 5 and 13 years for females and 7 and 15 years for males. Their mating system is generally unknown, but is thought to be polygynous, meaning one male mates with more than one female. Every 3 to 4 years, females give birth to a single 3-foot-long calf during the summer or autumn after a gestation period of about 1 year. Lactation lasts 12 to 18 months.