Short-Beaked Common Dolphin – Delphinus delphis


The Short-Beaked Common Dolphin, also known as the Whitebelly Porpoise or Saddle-Backed Dolphin, belongs to the family of the Dolphins (Delphinidae) and is thus part of the infraorder of the Whales (Cetacea). Delphinus delphis was first described in 1758 by Linnaeus.

Since it is widespread in European waters, it was for a long time the most famous representative of the dolphins. Only the Bottlenose Dolphin is more famous due the film Flipper.

Description

The back of the Short-Beaked Common Dolphin is black or brown, while the belly is whitish. The sides are yellowish in the front area and grey in the rear area. It can be easily distinguished from other species by the hourglass form on the sides created by the different colours.

The Short-Beaked Common Dolphin can reach a length of 2.40m and weigh up to 75kg, according to English Wikipedia even 136kg. Males are usually longer and therefore also heavier.

Delphinus delphis has up to 65 teeth in each half of the jaw, making it one of the mammals with most teeth.

Habitat & Distribution

Cetacea range map Short-beaked Common Dolphin.PNG
By Pcb21 at the English language Wikipedia, CC BY-SA 3.0, Link

The Short-Beaked Common Dolphin is distributed in a lot areas worldwide. These include the Mediterranean Sea, the Black Sea, the Northeast Atlantic, the West Coast of America, the coasts off South Africa, Oman, Madagascar, New Zealand, Tasmania and the seas between Japan, Korea and Taiwan. It is without a doubt the most common dolphin species off the coasts of Europe.

It prefers the open sea and rarely comes close to the coasts.

When diving in the Canaries it is almost impossible to encounter Delphinus delphis. However, they are regularly watched at Whale Watching boat trips.

Biology

Like all dolphins, the Short-Beaked Common Dolphin lives predatorily and feeds mainly on fish, sometimes also on cephalopods, that live up to 200m deep. It is also said that they eat about 9-10kg of food per day.

They form highly complex social associations, which can comprise up to 1000 animals. In the summer these associations are divided into smaller schools.

Short-Beaked Common Dolphins care for each other. It has already been observed how species companions can help wounded animals to get air on the surface. During childbirth, too, mothers are protected by other dolphins of possible shark attacks.

In addition, Delphinus delphis is a fast swimmer. They reach speeds of up to 60km/h. They like to ride in the bow wave of boats or other bigger whales.

Also interesting is that the Short-Beaked Common Dolphin sleeps only with one closed eye. One eye is closed for 5 to 10 minutes and then the other eye is the turn. Within a day they sleep about 3 to 4 hours.

Reproduction & Developement

Delphinus delphis, depending on the region and gender, attains sexual maturity between 2 and 12 years. In females, it is between 2 and 7 years, whereas in males it is with 3 to 12 years.

The gestation period is between 10 and 11 months. Furthermore, a newborn is about 70 to 100cm long and weighs around 10kg . At birth the young animals are born with the tail fins first, so they do not drown. Mothers help their calves for the first breaths on the surface. The young ones stay with their mother for up to 3 years, staying only a few meters away. Every now and then there are twin births. However, the young animals usually do not survive this because there is simply not enough milk. Calves are nursed for 6 months and during this time they only drink the mother’s milk.

The maximum life expectancy of Delphinus delphis is 40 years.

Apart from reproducing, the Short-Beaked Common Dolphin also seems to have sex for fun!

Sources

https://de.wikipedia.org/

http://www.marinespecies.org/

https://en.wikipedia.org/

http://animaldiversity.org/