The rough-toothed dolphin

Scientific Name: Steno bredanensis

Malti: Id-denfil ta’ snienu ippuntati

–

The rough-toothed dolphin (Scientific name: Steno bredanensis) is a marine mammal classified under the family delphinidae. The species has a dark grey or bluish cape with white or pinkish white underside and can reach up to 150kg in size and 2.8 m long. This dolphin is generallyidentified at sea due to its distinctive head shape, since unlike other dolphins which have a prominent beak; the head of the rough-toothed dolphin is conical. This means that it has a narrow beak which blends into its forehead without a crease. Other distinctive features in this species is that it has a whitish colour around the lips and its narrowness of its head together with its unusually large eyes, give it a reptilian appearance. Also, the pinkish or yellowish white blotches and spots found especially on its lower half of the body can may it distinguishable from other cetaceans, if they can seen whilst out at sea. The skin is peeled allowing new cells to replace old ones; this ensures smooth skin enabling them to swim with less or no resistance. Its common food is fish.

The rough-toothed dolphin’s distribution is poorly known, probably since it is rarely seen. It prefers to live in warm waters around the world and tries to avoid cold surface waters and cold currents; however it is never numerous. Entanglement in fishing gear is a large threat to these dolphins, and some of this species have been reported caught in gillnet and driftnet fisheries in Sri Lanka. Also, it has been noted that Maltese fishermen are probably spotting this species to the east outside Maltese waters.

Its behaviour is very typical to all dolphins but it’s harder to observe since it can sometimes be submerged for more than 15 minutes. It swims very rapidly and bow rides, but not as readily as other tropical dolphins. It however communicates using clicks and whistles like the majority. The rough-toothed dolphin is found in groups of 10-20, and in rare cases they are found in groups of several hundred.

In the Mediterranean Sea, the rough-toothed dolphin is mainly present towards the eastern side in the Levantine Sea. In fact, there has been very frequent encountered in the coastal waters of Cyprus, Lebanon and Israel. On the other hand, in Maltese territorial waters, this species is considered to be vagrant and/or occasional with the possibility of being present.