Sperm Whale

  • Irish name: An Chaisealóid
  • Latin name: Physeter macrocephalus
  • Size: 11 – 16 m
  • Diet: Squid, mesopelagic and demersal fish.

The head appears square-shaped while taking up 1/3 of the body’s length. They have a single blowhole diagnostically angled to the left and well forward on the head. The dorsal fin is rounded and lumps occur on the dorsal side of the tail stock. The skin appears wrinkled from the eye to tail stock and is coloured grey overall. Conical teeth are present in the lower jaw only.


They produce a 4 m left slanted blow. They undertake deep foraging dives in excess of 1,000 m. Fluking takes place at the start of deep dives but breaching and spy hopping take place occasionally.


Sperm whales occur in offshore deep water habitats along the continental shelf. Adult males predominantly occur due to the cool water temperatures present but at least four females have stranded in recent decades.

Sperm Whale Sightings 2005 – 2017

Downloadable Detailed Species Information


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