Wildlife Sightings Blog
Dolphin watching on the Isle of Mull
The largest of the
bony fish, this species has the appearance of a flattened disc
with no real tail, but they have large oar-shaped dorsal and
ventral (or anal) fins. As a whole the species can reach lengths
of 3.3metres, however the individuals seen around the UK tend to
be slightly smaller, an average of 1.8metres.
Due to the large dorsal and the fact it is a relatively unknown
species, Sunfish are occasionally mistaken for Basking Sharks as
they often lie high up in the water column with the dorsal fin
waving above the surface as in a Shark. They can also be seen on
their side at the surface and in this position they will appear as
a pale disc shape in the water.
A largely tropical fish, Sunfish come to the UK waters in the
summer months it is likely that Sunfish come to our waters to feed
on Jellyfish throughout the summer months. Their diet is also made
up of Crustaceans, Squid, small fish and Eel Grass. The majority
of the diet is nutritionally poor and therefore the sunfish has to
consume large amounts to sustain its large size. The range of prey
also shows that the fish feed at many levels, rather than just at
the surface as once thought.
Sunfish are commonly seen basking on their side at the surface.
There are a couple of possible reasons why they do this; the first
is to warm up after a dive into the colder, deep water, the second
is that they often get skin mites and by lying at the surface the
sea-birds, especially Gulls will come and feed off the mites and
clean the skin.