Spotties of East Anglia

One of the things we love about wild trout is their amazing variability in colour and spotting patterns. Our Conservation Officer team often share photos of the fish that they catch on WhatsApp, and the ensuing discussion is less about the size of the fish or the fly it took and much more about the colour and spotting patterns. A recent catch by Rob Mungovan prompted one such discussion.

Rob is our Conservation Officer for the East of England. His home town of Cambridge would not spring to many anglers’ minds as a hot spot for trout fishing. The rivers of East Anglia suffer more than most from low flows and over-abstraction in addition to the usual issues of water quality and poor habitat, so there are plenty of projects to keep Rob busy. He knows his patch so well that he can winkle out a few beautiful wild trout from his local rivers at the end of the working day. 

The photos below are of two trout caught on the same stretch of river on the same evening. The difference between them is striking. Both show every indication that they are wild fish, not farmed and stocked. The yellow-bellied fish has a very artistic looking line of red spots with white halos along its lateral line. The other fish is silvery and much spottier.

Robs Cam trout 2 May 24
Robs Cam trout 1 May 24

Why?

The colour and spotting pattern of trout is a function of their genetics and their environment, developing suitable camouflage to avoid predation. This is why trout in peaty streams and lakes often have golden bellies and sea trout are silvery.

Trout can also change colour quickly, like a chameleon, if they move to an area with a different coloured substrate. Anglers who regularly fish the same river come to recognise a certain consistency in colouration and spotting pattern, but there are surprises, such as Rob’s example. Some of these can be explained by trout adapting to a particular niche within the same water body. For example, peaty mountain lakes can hold a buggy eyed, silvery trout in deep water and yellow-bellied trout in the margins.

Some trout can be not only physically distinct, but genetically distinct too, in some cases forming what are now regarded as separate species that feed and breed differently (the most famous example being the ferox, gillaroo and sonaghan of Lough Melvin). It’s very likely too that, even within a single river, there will be genetically distinct groups of trout. Find out more about the Lough Melvin trout and trout ecology generally on the Brown Trout page of this website or take a look at the Trout Facts page for more bite sized fascinating facts about trout.

Quite why the trout the Rob caught are so physically different remains a mystery. We’re sure he will be back with his rod to sample more of these beautiful fish.

Spots1
Spots2
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Spots3