There are two types of dolphin species in the Musandam Region:
Humpback dolphins: (Sousa Chinensis) that can be found in the Sham Bay.
Bottlenose dolphins: (Tursiops Aduncus) that is rather found outside of the bay.
The Humpback Dolphin: Sousa Chinensis.
The species is also frequently called the “Chinese white dolphin”, “Pacific Humpback dolphin” or “pink dolphin”.
1. Description
The Humpback dolphin is stocky with a very arched back, with a hump on its forehead more or less pronounced according to the geographical region in which it can be found.
It has a long and thin beak.
The males can measure up to 2.7 m long (8.8 ft.) and can weigh 260 kg (570 lbs.), whereas the females are smaller and can measure up to 2.4 m long (7.9 ft.) and can weigh up to 170 kg (370 lbs.).
The skin color depends on the population type and the age of the individual. It can vary from a gray-blue color to a lighter gray, and can even be light pink or white (the last being more common for the Chinese subspecies).
Its abdomen is often of a lighter color.
Newborns are darker skinned than the adults.
2. Manners and behavior
The Humpback dolphin is sociable and usually travels in schools of 3 to 7 individuals, although it can sometimes grow up to having 25 to 30 individuals.
The group, or ‘pod’, is made of dolphins of all sexes and ages, and a hierarchy is established within it.
The Humpback dolphin remains quite fierce and tends to keep a distance from boats. He is seen mostly from afar when he comes up for air.
Just as he prepares to dive into deeper waters, we discover his caudal fin. He soon surfaces again though. A grown adult can stay underwater for 2 to 8 minutes.
3. Geographical distribution
The species is found in Cape Province (South Africa), Australia, in the Persian Gulf and near Asian coasts. However, we consider to this day that the population is composed of several species of “sousa”.
Humpback dolphins are not known to be migratory, although some seasonal movements have been recorded
4. Natural habitat
Humpback dolphins live in warm waters: 15 ° to 36 ° C minimum, and in shallow places: 20 meters deep preferably, but rarely beyond 25 meters. They are found near bays, estuaries, mangroves and reefs.
These dolphins prefer to remain near the shores, but we sometimes find them in rivers depending on the tides.
Specimens were observed in the Mediterranean Sea, after they went up the Suez Canal.
5. Diet
Humpback dolphins feed on estuarine fish and coral, crustaceans and molluscs.
They hunt both individually and in groups. For the latter, they use echolocation.
6. Life Cycle
They live for approximately 40 years. Female humpback dolphins reach sexual maturity at about 10 years old, and males at 13 years old.
Births occur in spring and summer after a gestation of 10 to 12 months.
Newborns are usually 1 meter long and weigh about 15 kg.
They are weaned at around two years old, even if they are able to eat solid food from six months onwards.
7. Threats
A small number of dolphins are still killed for consumption in the Persian Gulf, near the Indian coast and near Madagascar, but chemical or even sound pollution of the humpback dolphin’s habitat remains the major threat to the species.
As these dolphins swim in coastal areas, they are also often victims of fishing nets and gill nets that are installed to protect the beaches from shark incursions.
Studies of the species are rare but those made reveal a significant decline in the population.
Indo-Pacific bottlenose dolphin
Order: Cetacea
Family: Delphinidae
Genus and species: Tursiops Aduncus
1. Description
It has a relatively robust body, a rostrum of moderate length and a tall, curved dorsal fin (sickle-shaped), unlike the common bottlenose dolphin.
Its skin is grey, darker than the humpback dolphin.
Its size may vary depending on the region.
For males: mean length and weight of 2.38 m and 160 kg with a maximum of 2.7 m and 230 kg (Jefferson et al.2008).
Life cycle: unknown, probably the same as that of the common bottlenose dolphin, meaning about 40 years for male specimens and 50 for the females.
Swimming speed: fast
Teeth: The lower jaw displays about 40 teeth.
Peculiarities: The species is not recognized by the IUCN. For many scientists it is
not a separate species. Yet the DNA of the Indo-Pacific bottlenose dolphin is different from that of the bottlenose dolphin. Furthermore, this species’ “personality” is more similar to common dolphins.
Common behavior: The Indo-Pacific bottlenose dolphin is an active animal that loves games. Individuals may jump out of the water. They like surfing stern waves.
2. Geographical distribution
Its distribution is uneven. It begins on the east coast of Africa and goes up to the Red Sea and the Persian Gulf.
Further away, groups can be found in the east, towards Taiwan and Australia. We do not know if there is a connection between these two areas.
Above: Dolphins across from Khasab in the Musandam region.
