BRITISH FRESH-WATER FISHES 



Flounder.— Pleuronectes fiesus (Fig. 64). This, the 

 last species which it is desirable to include in our list of 

 fresh-water fishes, migrates considerable distances up- 

 river, and although there are many other species of 

 marine fishes which frequent brackish and even fresh 

 v/ater, there is not much amiss with the selection that has 

 been made in this volume, and the Flounder is certainly 

 entitled to inclusion in preference to several others. It 

 is, as is well known, one of the flat-fishes, having an 

 ovate body, with an array of fins extending at least three- 

 fourths of the whole. The body is covered with small 

 scales, and along the inside length of the dorsal and 

 ventral fins there is a row of spinous tubercles, as also a 

 little group at the head end of the lateral line. The 

 general colour is greyish-oHve, but there is considerable 

 variation, and one writer says " it varies from nearly 

 yellow to almost black." In some specimens there are 

 orange spots, as in the Flounder's nearest relative, the 

 Plaice Left-sided, as well as right-sided, examples are 

 frequently forthcoming, as also specimens coloured aHke 

 on both sides. It resorts to shallow water close inshore 

 and delights in a sandy bottom. Although of sluggish 

 habits, it regularly ascends a number of our rivers, and 

 when swimming, its movements are most fascinating to 

 watch. When I was on Loch Lomond in the Autumn of 

 1922 a Flounder was captured in the famous Loch, 

 the first that had been known to appear there for over 

 twenty years. The food consists of crustaceans, molluscs, 



worms, and small fishes. The spawning time is of ex- 

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