The Fishes of the Lower Wharfe Basin. gor 
canglers’ point of view the fish has little value. It appears to 
be well distributed in Wharfedale, and can be found as far up 
the valley as Otley. 
THE MILLER’s THUMB can be distinguished from the other 
members of the order by its large and flattened head. It is 
remarkable for its voracity, is active in its habits, and lives in 
‘solitude in the darkest, most sluggish and deepest parts of the 
river. In this country it never grows to a greater length than 
five inches. ' It has no scales, and seems to’prefer soft or muddy 
ground to a clear and sandy bottom. When disturbed, it 
darts away and rapidly obscures itself in a cloud of mud. 
Where the roots of overhanging trees have been exposed to 
the action of the current, the Miller’s Thumb or Bullhead can 
generally be found. It varies somewhat in colour, but as a 
rule it has very dark brown or even black markings on a dirty 
white base. Looking at the fish from the front, it has a most 
repulsive appearance, owing to the superior position of the 
eyes and the disproportionate gape of the mouth. 
THE STICKLEBACK is rarely to be met with in the River 
Wharfe itself, but it is fairly common in the pools and ditches 
which lie inits basin. In Wharfedale at any rate, it appears to 
prefer stagnant torunning water.* It spawns in May and June, 
and at this time of the year the Stickleback constructs a nest 
the better guidance and accommodation of his prospectve for 
partner, in which she deposits her eggs. The male fish then 
assumes a blood red colour on the throat and breast. Although 
the Stickleback is one of our smallest fishes it is extremely 
pugnacious. Like the Perch it is gregarious and with suitable 
traps—not necessarily baited—may be taken in large numbers. 
THE FLouNDER. This migratory fish occurs in the Wharfe 
from Tadcaster downwards. 
It ascends rivers for long distances, is very prolific, but 
never attains a very large size in fresh water. Its flesh is 
of fine flavour. It possesses in a remarkable degree the power 
of adapting itself to its environment by assuming the colour 
of the bottom. This fact makes it indistinguishable from the 
rest of its surroundings, except to a very experienced eye. 
The colour is generally brown or drab, which may be 
relieved somewhat by the superposition of orange or very dark 
‘brown spots. Its food consists of worms, small fishes, and other 
animal substances. It ascends estuaries to spawn; which 
process generally takes place from December to February. In 
Yorkshire they are known as ‘ flatties.’ 
At one time large numbers were caught by means of a 
three pronged spear which was thrust into any likely place. 
_ * Inthe neighbouring valley, Airedale, the Stickleback is plentiful in the 
river, and as Mr. Booth has pointed out, it forms the principal food of the 
Kingfishers.—ED. 
1913 June 3. 
