WHALES – TEETH
By Amelia Meyer
In certain whale species, teeth exist instead of the baleen plates of other whales. These whales are part of the Odontoceti suborder of Cetaceans, which eats mainly fish and crustaceans. Some toothed whales also eat smaller mammals (such as dolphins or seals). This is made possible by the teeth, which are used to grasp and tear at captured prey.
The individual teeth of these whales are all very similar to one another, unlike humans and many other animals that have incisors that look very different to molars, for example. Each tooth only has one root. They have a small central pulp cavity, which disappears when the growth of the tooth is complete.
These teeth consist of dentine, a layer of cement and an enamel tooth covering, as are human teeth. In many whales, the enamel wears down to such an extent that they have only dentine stumps left remaining. In fact, in some species, the enamel layer never even develops due to lack of necessity. These species include the Narwhal, Sperm Whale and Pigmy Sperm Whale.
Whales do not shed their first set of teeth (or “baby teeth”) to replace it with permanent teeth. Rather, they have only one set of teeth for their entire life. This number of teeth varies from species to species. In some whales, some of the teeth never actually break through the gum, rendering them useless, but present, although it may not appear so from first glance.
When hunting, the whale uses its teeth to grasp and tear at its prey. However, they are not used for chewing, since chunks of meat (and even entire animal victims) are swallowed whole. Often, the prey is seized in the jaws of the whale and then simply squeezed towards the throat and swallowed.
The Sperm Whale has between 18 and 30 sets of teeth in only the lower jaw. When it closes its mouth, these teeth slot into corresponding indentations in the upper jaw to allow for a comfortable fit. Although these teeth are not used to their maximum chewing and grinding potential, they are incredibly firmly planted in the gum tissue. These teeth usually only emerge from the gums when the Sperm Whale has already reached sexual maturity. Due to lack of use, these teeth often decay, are riddled with disease, or covered with barnacles.
On the other hand, the Narwhal has no visible teeth at all, despite being part of the toothed whale order. When hunting, the Narwhal uses the sharp edges of its jaws to capture its prey. However, it is important to note that Narwhal foetuses have two tooth buds, since the left one of these eventually emerges from the gum and forms a spiral tusk that can reach approximately eight feet, or just under 2.5 metres, in length. This is a phenomenon common to the male Narwhals, but there have been a small number of females displaying impressive tusks too. In some fascinating cases, males have even sprouted two tusks; one from each of the tooth buds.
Unlike baleen whales, whose tongues are simply a massive muscle laying at the bottom of their mouth, toothed whales have tongues with a short free tip that they may use to manoeuvre their prey to a small extent.
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