Cetaceans of the Mediterranean Sea

Fin whale

The fin whale is the second longest animal in the world, after the blue whale, reaching a length of 23 m and weighting up to 50 tons. The common name refers to the prominent and falcate dorsal fin, found on the posterior third of the body. However, this is not the only distinctive trait of this species: the coloration on the lower jaw  is asymmetrical, with the blaze (white coloration) extending onto the upper lip on the right side. These two features, together with the v-shaped chevron behind the head, are used to distinguish the individuals through the photo-identification.

  • Scientific name:: Balaenoptera physalus
  • Common name: Fin whale
  • Suborder: Mysticeti
  • Family: Balenopteridae
  • Genus: Balaenoptera
  • Species: Balaenoptera physalus
  • Habitat: Pelagic zone
Fin whale FAR


Fin whale CLOSE


Fin whale

Habitat and distribution

Generally found over the continental shelf, the fin whale prefers waters deeper than 200m or with a high concentration of prey. It lives in all major oceans, from temperate to polar waters in summer and sub-tropical waters in winter. The Mediterranean Sea is home to a resident population that migrates every year from the southern winter breeding ground to the northwestern waters that in summer are rich of food.


A fin whale can eat more than 1 t of food per day and feeds intensively in summer almost exclusively on krill and copepods, at depths up to 180 m and sometime at surface. The technique used is called lunge-feeding, that typically involves rolling on the right side, opening the mouth to 90° angle and filling the mouth with 70,000 l of water. After the whale’s jaws close, the water is squeezed out, and 10 kg of krill are finally engulfed.


Capable of swimming exceptionally fast, the normal cruising speed of a fin whale is 10 to 15 km/h and can reach 37 km/h for short bursts when feeding. It is frequently seen alone or in small groups of 2 to 7 individuals. Sometimes it associates with dolphins, pilot whales and in feeding aggregations with other whales.

Vocalizations include songs composed of single pulses, representing one of the loudest biological sounds in the ocean that can be heard from hundreds of kilometers away.

Lifespan and reproduction

A fin whale can live up to 90 years. Females reach sexual maturity at 7-8 years, male at 5-7 years. Calving happens every two years, giving birth to a single calf. Males are believed to compete over females for reproduction. In some regions out of the Mediterranean Sea, fin whales can sometimes mate with blue whales, generating hybrids.


  • The fin whale is the most frequently reported as victim of vessel collision, making it the most vulnerable species to ship strikes.
  • It is still being hunted in the North Atlantic under the IWC’s aboriginal subsistence regulations.
  • Underwater noise, especially military sonar and seismic activities, interrupts the normal behavior of whales and drives them away from areas important to their survival.
  • Other threats include entanglement in fishing gears, overfishing of prey species and ingestion of microplastics.

Cetaceans of the Mediterranean Sea

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