CHARACTERISTICS AND HABITS OF FISHES 25 



Sprat found from the North of Europe to the 



Mediterranean 



Pilchard ranges from the English Channel to 



Madeira and the Mediterranean. Skipper " sardines " 



are young herring, pilchard, and brisling. 



There is also 



Mackerel found from the North Sea to Madeira 



and the Mediterranean. 



(3) The shallow-water of the seashore is inhabited 

 by certain animals ( shellfish') not found elsewhere, 

 including various mollusca, e.g. mussel, cockle, oyster 

 and periwinkle, and Crustacea, e.g. lobster, crab, prawn, 

 shrimp. In addition to these, there are various species 

 of immature offshore fish, e.g. plaice and dabs. The 

 inhabitants of this shallow, coastal water are called 

 " littoral " fish. The distribution of such littoral fish 

 depends not only upon the water temperature and the 

 amount of light, but also upon the character of the 

 shore whether it is rocky, or soft and sandy and more 

 especially upon the animal and vegetable products of 

 the adjacent land, e.g. plants, seaweed, worms. Littoral 

 fish do not swim very far, but become scattered inadver- 

 tently over considerable distances by currents and other 

 mechanical means. 



Certain kinds of shellfish, for example oysters, mussels, 

 cockles, live in the sand or attached to the stones or 

 seaweed on the seashore, generally between high and 

 low watermarks. They obtain their food from the water 

 as it streams over their gills. They require adequate 

 room for growth and development, and constant irriga- 

 tion by water containing sufficient floating food. When 

 mussel beds or oyster beds become overcrowded, the 

 fish are ill-nourished, their health is impaired and their 

 growth is arrested. It has been shown that, if they are 

 transferred to new beds, their condition rapidly improves 



3 (145/H) 



