Marine experts and members of the public were amazed last week by the appearance of a Dwarf sperm whale (Kogia sima) off the Cornish coast.
British Divers' Marine Life Rescue were called in by Falmouth Coastguard after they received reports of a small whale stranded on sea defence boulders at Mounts Bay, Penzance, but by the time they arrived members of the public had managed to push the injured whale back into the sea.
The small cetacean was initially mistaken by some for a harbour porpoise but was later confirmed as the first sighting of a Dwarf sperm whale in UK waters. Once back into the water it swam around the bay for around 90 minutes before disappearing, but due to its injuries experts are not optimistic for its longer term prospects.
Dwarf sperm whales are the smallest of cetaceans commonly described as whales, being smaller than many dolphin species with maximum lengths of around 2.7m/8.9' and weights of around 250kg/550lb. Generally found in deep water just off the continental shelf, there have been few recordings of this predominantly warm water species from European waters.
They are largely solitary, feeding mainly on squid and crustaceans and the abundance of these in Cornish waters this year may have attracted it to unfamiliar shores.
Both the Dwarf, and its closest relative the Pygmy sperm whale (Kogia breviceps) have a strange sac in their intestines that contains a dark fluid which they can expel when frightened, possibly to confuse and disorientate would-be predators.
You can watch a video of this UK first below:
Why not take out a subscription to Practical Fishkeeping magazine? See our latest subscription offer.