European Grayling (Thymallus thymallus)
Weight: Small fish of between 8oz and 1lb are often taken by anglers fishing the upper reaches of Britain’s rivers for roach and dace. A grayling over 1lb is seen by many as a good fish, and a 2lb-plus fish is a real specimen on many venues. However there are a few rivers, mainly chalk streams in the south of England that are know to regularly produce a 3lb-plus monster
British Record: 4lb 3oz, SR Lanigan in 1989 from the River Frome in Dorset
Length: Rarely exceeds 30cm, but some have reached 60cm in Europe
Age: Can live for up to 15 years in the wild
Preferred habitat: Prefers clean, well-oxygenated, fast-flowing water over gravel shallows during the summer, but tends to move into slower, deeper pools during the winter. Younger fish seek the cover of bank side vegetation close to areas of sand and gravel where they feed. There are a few stillwaters that hold grayling including Bala Lake in Wales
Feeding: The fish has a natural diet of bottom-living insect larvae, crustaceans and mollucs, but during spring and throughout the summer and early autumn they are regularly seen plucking insects of the water’s surface during the hatch. On occasions large grayling have been known to eat small fish
Hybridisation: Is not known to cross-breed in the UK
Maturity: Males two years and females three years
Spawning: As winter approaches the fish start to shoal and spawn as the temperature reaches four degrees celcius. The males are territorial and court females with a display of its large, beautiful dorsal fin. Eggs, up to 10,000 at a time in large females, are laid in redds and take three to four weeks to hatch.
Natural predators: Pike
The grayling is streamlined and slightly flat-sided. Young fish are silvery/green in colour and have grey/blue parr marks along their flanks. Mature fish have a silvery grey-green back and flanks with black speckling. The belly is off-white.
This is quite small with the upper jaw protruding beyond the lower. Both jaws have a row of very small teeth.
The grayling has a large eye with a golden iris and a pear-shaped pupil.
Convex in shape, these are a light orange/brown in colour.
The male of the species has a much larger ‘sail’, that during the breeding season it displays in courtship. The colour is a steel-blue with a red/orange margin that intensifies during spawning.
These are also convex in shape with thick rays and are predominately light brown in colour.
Although seen as a coarse fish, the grayling has the fleshy, grey-brown-coloured appendage that you find on species in the salmonoid family.
A fairly large convex-shaped fin that is a blue-grey in colour that gets darker at the tip.
The grayling has a narrow ‘wrist’ and a forked tail, which is a blue-grey in colour close to the root before darkening to a deep grey at the edges. The full, almost spade-shaped fin is what gives the perch its acceleration when it ambushes its prey. The upper half is a light orange with a deeper coloured tip and the lower half a deep red/orange.
The Life Cycle
Cool, clean, fast
Grayling are most commonly associated with clean, cool, fast flowing rivers, where they will often form large shoals. If you are able to observe a shoal at close quarters it is easy to spot the high dorsal that is so characteristic of the species as they move back and forth in the flow. In the male fish the dorsal is particularly large and often stunningly coloured with several rows of bright spots. The male grayling uses his oversized dorsal fin to impress female fish at spawning time.
Coarse or game?
It is not uncommon to hear anglers debating whether the grayling should be considered a game fish or a coarse fish. The confusion arises from the presence of a fleshy adipose fin positioned behind the dorsal fin. Recently the presence of the adipose fin has led scientists to group the grayling in the salmonid family as a sub-family called the Thymallinae. Interestingly the Latin name of the fish Thymallus thymallus, originates from the smell of the slime, skin and flesh of the grayling, which has a strong aroma of the herb thyme.
Ice Age imports
Grayling are believed to have entered our river systems while Britain was still connected to continental Europe at the end of the last ice age. Research has indicated that the grayling’s natural distribution was historically relatively limited and it is only in the last 200 years that they have become widespread through stockings undertaken by man.
Although grayling spawn in the spring, there is some variation in the timing of their spawning depending upon location. In northern England they may breed as late as May, while their southern relatives are often observed spawning as early as February. Grayling spawn amongst clean gravel and the lively courtship which is involved in the spawning process, frequently results in the eggs being lightly buried. The exact number of eggs that the female grayling can produce is also closely linked to geographical location, but as a guide a one kilo fish living in the River Test might produce approximately 5,000 eggs.
Short and sweet
Grayling are a very short-lived fish and in most British rivers a fish of six or seven years would be unusual! To make up for this lack of longevity they grow at a rapid rate. At the end of their first year they frequently achieve lengths of over 10 centimetres and it is not uncommon for a three-year-old grayling to be a foot in length!
To fuel this rapid growth the grayling is a ravenous feeder. Grayling eat a wide variety of adult and larval aquatic insects, terrestrial bugs, fish eggs and even the fry of other fish. For the angler, the huge appetite of the grayling is without doubt one of its most appealing features. Grayling will feed even on the coldest of days. In the past I have managed to catch a lovely bag of these cheerful characters even when the banks of the river have been blanketed with thick snow!