Whale hall: an insightful guide to marine mammals

Rear view of the skeleton of a male sperm whale — Pictures by Abdullah Ibrahim al Shuhi

Among the toothed cetaceans in Oman are the Finless Porpoise, Indo-Pacific Humpbacked Dolphin, Bottlenose Dolphin, Pantropical Spotted Dolphin, Spinner Dolphin, Striped Dolphin, Common Dolphin, Risso's Dolphin, False Killer Whale, Killer Whale, Short-finned Pilot Whale, Cuvier's Beaked Whale, Sperm Whale and the Dwarf Sperm Whale.

The Finless Porpoise, at less than 2m total length, is one of the world's smallest cetaceans as also the smallest cetacean known in the Arabian Gulf. This blue-gray porpoise has a round head without a beak, small flippers and spade-like teeth, but has no fin. Seen usually in small groups in coastal waters round Oman, the Indo-Pacific Humpbacked Dolphin, on the other hand, is the second most common dolphin in the Sultanate.

The hump or ridge from which the small backward-curving fin rises distinguishes it from other dolphins. It is usually gray with paler specks.The Bottlenose Dolphin is common in the coastal and deep waters.

It is the most commonly studied dolphin and is usually reported associating with people as it is inquisitive and playful. It is robust, dark, with a large head and stubby beak, and a crease between beak and forehead. The Spinner Dolphin lives over Oman's deep waters, occasionally inshore in Muscat area and often in large mixed herds with the slightly larger Common Dolphin. It is slender with a long beak and is distinguished by its habit of spinning when leaping high above the surface.

Skeletons with skull of a young Killer Whale on the right

A broad gray flank band separates its dark back and pale belly, and a dark stripe runs from eye to flipper.The Common Dolphin is most often seen along Oman's coasts in mixed herds with the Spinner Dolphin.

It is less than 3m long, slender, with a beak and a distinctive hourglass pattern on the flanks.The False Killer Whale is fairly common offshore, sometimes in large herds.

It is large, slender, all black, with a long tapering head, no beak, fairly tall curved fin, and small flippers that are sharply bent. The Cuvier's Beaked Whale, Killer Whale, Risso's Dolphin, Dwarf Sperm Whale, Sperm Whale and others are only rarely seen in Oman's waters.

Samples of bones on display at the hall

In the Whale Hall hangs the huge skeleton of a male Sperm Whale, which was stranded at Barka in September 1986. The whale was about 25 years old and 14 metres long but could have grown to 18 metres. Its bones weigh 3.5 tonnes, but the live animal would have weighed about 35 tonnes. All the bones are original except the teeth and digits, which are replaced by wood, and the cartilage, which are replaced by plaster.

Further, the earbones are missing. It has been painted to preserve it and to reduce its oily smell. The Baleen Whales spotted in Oman, on the other hand, include the Minke Whale, Sei Whale, Bryde's Whale, Blue Whale, Fin Whale and the Humpback Whale.

The 15-m long Bryde's Whale is seen off Oman in most months, occasionally with its young, and thus possibly breeding here. The three ridges from blowhole to snout, and a small fin distinguish it.

Skeletons on display

Pictures of whales and dolphins found in Omani waters

The 16m-long Humpback Whale is the largest baleen whale most commonly seen in Oman's waters, particularly off Dhofar during autumn and spring, the season of birth and courtship.

During courtship, lone young males sing the same song that can last for half an hour, and can be repeated day and night. These sounds can travel many kilometres underwater.

The other baleen whales — Minke, Sei, Blue and Fin Whales — are rarely seen in Oman. One of the special features of the Whale Hall is the recorded sound of the three cetacean species. It is charming to hear the songs and grunts of the Humpback Whale, the musical sound and clicks of the Sperm Whale, and the seeming tweets and whistles of the Common Dolphin. The Whale Hall is full of information about these underwater mammals that researchers, students, and other curious visitors will find valuable. Further, tourists who plan to go on a dolphin cruise may as well visit the Whale Hall for a better understanding of what they might see off Oman's coasts.

Skeleton of a male sperm whale