32 SALT-WATER FISHES 



knowledge when desirous of capturing a certain kind of 

 fish for which there is a brisk demand at the time. The 

 angler knows quite well the difference between, for instance, 

 rock-fish and those which dwell, or at any rate seek their food, 

 on sandy ground. This is the simplest, and also the most 

 important, distinction of the kind. To the rock-fish belong, 

 to quote a few famihar examples, the conger {Conger), pollack 

 and pout {Gadus), rocklings {Motella), wrasses {Labrus), 

 breams (Pagrus), sticklebacks (Gasterosteus), gobies {Gobius), 

 and suckers {Lepadogaster). These are only a few of our 

 rock-fish, and many more might have been cited. 



As equally familiar examples of sand-dwelling fishes we 

 may take the flat-fish {Heterosomatd), of which the afore- 

 mentioned topknots {Zeugopterus) are regarded as evincing 

 a preference for rocky ground more than any of the rest, the 

 sand-eels (^Ammodytes), the gurnards {"Trigla), whiting (Gadus), 

 skates (Rata), and weevers (^rackinus). Many of our 

 commonest fish, like the bass (Labrax), most of the sharks 

 (Selackii), cod {Gadus), and dory {Zeus), are found on both 

 rock and sand, and one or two fishes that keep almost entirely 

 to the rocks by day seem to wander out in search of food on 

 the sand by night. There are, as a matter of fact, other 

 characteristic localities for some of our sea fish besides this 

 distinction of rock or sand. Some of them, like the bass and 

 grey mullet (Mugil) are particularly partial to estuaries and 

 even the lower reaches of tidal rivers. Others, like the pout 

 and wreck-fish (Polyprion), are found in the neighbourhood ot 

 wreckage, the former fish being associated with sunken wrecks 

 of some age, the latter with floating timber from recent 

 disasters. 



III. The fishes of our seas considered in the present 

 volume practically belong without exception to what would 

 be called shallow water, since the term " deep-sea fishes " has 

 been restricted by general consent to those extraordinary 

 luminous and other forms that are from time to time brought 



