Whales

Species of Whales

Physeter macrocephalus

sperm whale draw copyLength:

8 – 12 m (female), 16 – 18 m (male). It is the largest toothed whale in the world. Sexual dimorphism has been recorded in the species, with males weighing twice as much and measuring three times the size of females.

Weight:

24,000 kg (female), 57,000 kg (male)

Life span:

>70 years

Feeding habits:

Mesopelagic cephalopods (giant squid), some demersal fish (e.g. rays). When diving for their main food source (cephalopods), sperm whales go between300 and 600m deep per dive and stay submerged for 20-50 minutes. However, there are some reports of individuals reaching depths of over 1000 m, returning to the surface for air after an hour.

Habitat:

Migratory pelagic (i.e. normally found in open waters) species, especially along the continental slope.

Distinctive characteristics:

The sperm whale is simply recognized by its large, trunk-shaped square head. The dorsal fin is triangular in shape and not very obvious, and the blowhole is situated on the left side of the dorsal area.

Population trend:

The population in the Mediterranean is smaller than 2,500 mature individuals. Males are observed to swim alone, whereas females and young ones are found in social groups usually made up of 10-12 members and 1-2 calves.

Main threats:

By-catch in illegal driftnets, collisions with large ships (particularly high-speed ferries), as well as noise pollution caused by sonars and seismic exploration.

Status (IUCN):

Endangered (EN)

Balaenoptera physalus

fin whale copyLength:

World's second largest cetacean species after the blue whale. Usually ranging between 13 and 19m, but it has been recorded to reach 25 m (second largest animal on Earth).

Weight:

40 – 50 tones

Life span:

>80 years

Feeding habits:

Mainly prey on zooplanktons.

Habitat:

Pelagic (i.e. normally found in open waters) species. They migrate through deep offshore waters, continental slope and shelf waters at depths between 400 and 2,500 m. Usually it is found solitary or in small groups, but it has been known to congregate in large groups.

Distinctive characteristics:

The fin whale has a small dorsal fin situated on the posterior third of the body and has a central blowhole with two exit orifices. The lower mandible has a characteristic asymmetric coloration – white on the right, dark on the left.

Population trend:

It is the most common whale species in the Mediterranean, regular throughout the western and central basins, but rare in the Aegean. Although population trends remain unknown, the Mediterranean population is thought to contain fewer than 10,000 mature individuals.

Main threats:

Vessel collisions (particularly high-speed ferries), shipping noise and vessel disturbance, seismic air guns, marine pollution and entanglement in illegal driftnets.

Status (IUCN):

Data deficient (DD)

Ziphius cavirostris

Cuvier's beaked whale copyLength:

5.1 – 6.9 m

Weight:

2,000 – 3,000 kg

Life span:

>60 years

Feeding habits:

Mainly deep sea cephalopods

Habitat:

Pelagic (i.e. normally found in open waters) species often associated with deep slopes and canyons. Normally found in small resident pods, moving in groups of 2-3 individuals.

Distinctive characteristics:

This species is difficult to observe as the individuals spend little time at the surface. They are identifiable due to their stout body, small sloping head and curved mouth, which gives them a characteristic s-shaped smile. The dorsal fin is small and situated on the posterior third of the body. The species also has a blowhole shaped like a crescent moon. Adults usually have many scars on their body as a result of battling. Males have two teeth that protrude out of the mouth.

Population trend:

Very little is known about the Cuvier’s beaked whale populations in the Greek seas and the Mediterranean overall.

Main threats:

Noise pollution, mainly from military sonar and seismic exploration for hydrocarbons. Furthermore, a mass stranding and subsequent fatalities of this species occurred in the Ionian and Adriatic seas in 2011 and coincided with a military exercise carried out in the area.

Status (IUCN):

Data deficient (DD)

Phocoena phocoena

harbour purpoise copyLength:

1.3 – 1.8 m

Weight:

50 – 90 kg

Life span:

~25 years

Feeding habits:

Wide variety of fish and cephalopods.

Habitat:

Coastal and shallow offshore waters.

Distinctive characteristics:

Identifiable by its plump body, rounded head, low triangular dorsal fin and the lack of beak.

Population trend:

The Mediterranean and Black Sea populations are isolated and there is no known migration. They have only been recorded in the northern region of the Aegean Sea.

Main threats:

Overfishing, by-catch, habitat degradation and noise.

Status (IUCN):

Endangered (EN)

Mesoplodon sp.

Length:

up to 7 m

Weight:

2,000 – 3,000 kg

Life span:

Unknown

Feeding habits:

Mainly feed on squids and deep sea fishes.

Habitat:

The species is mostly found in offshore deep waters, but their close to the shore encounters have also been recorded. They prefer water depths between 700and1000m.

Distinctive characteristics:

This species is difficult to observe as the individuals spend little time at the surface. It is easy to get mixed with Cuvier's beaked whales. They are identifiable due to their stout body, small sloping head with a longer beak compared to the Cuvier's beaked whales. The dorsal fin is small and situated on the posterior third of the body.

Population trend:

The population trend in the Mediterranean Sea is unknown

Main threats:

By-catch and pollution

Status (IUCN):

Data deficient (DD)

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