Family ZIPHIIDAE (Beaked Whales)

About 20 species make up this little known group of toothed whales. Some of these have been hunted by small-whale fisheries, but not much information is available about them. New species of beaked whales have been described even recently from skulls. Only a few ziphiids have been recorded from India and nearby.

All the beaked whales live in deep waters and their common features include a pair of throat grooves, the lack of a notch in the tail flukes and a dorsal fin placed well back on the body. They have narrow and beaklike snouts. They have unobtrusive habits and are difficult to identify. This coupled with their deep-water preference may be the reason for their apparent rarity.

The size of the ziphiids ranges from that of the 4.5 m Hector’s Beaked Whale Mesoplodon hectori to the 13 m Baird’s Beaked Whale Berardius bairdii.

Beaked whales are all deep divers. These animals feed mostly on squid, which are swallowed whole. The number of teeth is relatively small, a feature typical of a squid diet. These teeth are of little use in catching their prey. In most species, the females have no functional teeth and the males often have only one or two pairs in the lower jaw, which are sometimes exaggerated to the point of being tusks. The function of the teeth is unknown.

The adult male Strap-toothed Whale Mesoplodon layardii has tusks on each side of his lower jaw up to a foot long, which wrap around the upper jaw. These teeth prevent him from opening his mouth wide. It is intriguing how he captures and swallows squid. He may just suck them up.