FISHES 159 



11. The Hake (Merluccius vulgar is), a very voracious species, attacking 

 herrings and pilchards, and hence known as the " HERRING HAKE." Length, 

 3 or 4 feet ; colour, whitish, greyer on back. A valuable fish, known in its 

 dried state as " stock-fish." 



12. The Ling (Molya vulgaris). This is a much longer-shaped species than 

 the Cod, and reaches a weight of 70 Ib. The colour is grey, with an olive 

 tinge, silvery underneath, the fins edged with white. It is found chiefly where 

 the sea bottom is rocky. 



FLAT-FISH. 



Under this head come more than two hundred species, among which are 

 many of our British fish, such as the Turbot, Halibut, Flounder, Plaice, and 

 the Soles. They all keep (in the adult stage) to the sea bottom, are all car- 

 nivorous, and all have a remarkable life-history. They are not really " flat," 

 but " thin " fish. When first hatched, the young resemble ordinary " round " 

 fish, except that they are almost transparent ; they swim vertically, and have 

 an eye, as usual, on either side of the head. But very early in life they take 

 to lying down on their sides, and then the upper side becomes a darker colour, 

 curiously marked and patterned so as to resemble very closely the nature of 

 the ground on which they are lying. Indeed many of them possess the power 

 of altering their coloration to suit their surroundings. The under side does 

 not change colour, but remains white. In addition, the skull becomes twisted, 

 so that the eye, which is at first beneath, comes round to lie beside its fellow 

 on the upper side. If it be remembered that the edges of a flat-fish are really 

 its back and belly, this strange history will become clearer. 



1. The Turbot (Rhombus maximus) has its eyes on the left side, is about 

 2 feet long, and reaches 30 Ib. and more in weight. It feeds on crustaceans 

 and other fish, and is found on sandy bottoms round our coasts. It is ex- 

 tremely prolific, the number of eggs in one female having been estimated at 

 fourteen millions. 



2. The Halibut (Hippoglossus vulgaris) is the largest of all our flat-fish, 

 having its eyes on the right side. Specimens have been taken 500 Ib. in 

 weight, and as much as 20 feet in length. 



3. The Plaice (Pleuronectes platessd), one of our commonest flat-fishes, is 

 distinguished by the orange spots on its olive-brown side. It inhabits sandy 

 and muddy banks, where it lies partially covered, but with its eyes exposed, 

 and watchful for its prey. It feeds on molluscs, crustaceans, and worms. 

 Its average weight is between 2 and 3 Ib. It spawns in early spring. 



4. The Dab (Pleuronectes limanda) is distinguished by its light brown 

 colour, small, irregular dark spots, and the roughness of its small scales. 



5. The Flounder (Pleuronectes flexus) has an olive-green or brown upper 

 side, sometimes with yellow spots. The species prefers river mouths, where 

 the eggs are deposited; in fact, the Flounder often leaves the sea and goes 

 upstream, and can thrive in fresh-water ponds. 



