132 THE BOOK OF NATURE STUDY 



size, and has a short, thick body marked by a median and three 

 lateral rows of tubercles. It is readily recognised also by the 

 strong sucker on the under surface, by which it can fix itself to 

 rocks and so prevent itself from being washed away by the ebbing 

 tide, for it is a very poor swimmer. The young have no tubercles, 

 and when an inch or less in length make charming inhabitants 

 of the aquarium. They are very like tadpoles in appearance, 

 and dart vigorously through the water, stopping every now and 

 then to fix themselves by the ventral sucker. 



Related to the lumpsucker, but of more normal shape, in 

 that their bodies are elongated instead of being thick and 

 " lumpy," are the gobies, of which several species are common 

 off British shores. The pelvic fins can be pressed together to 

 form a sucker by which these little fish can anchor themselves 

 temporarily, but they are also capable of swimming about actively, 

 and form interesting occupants of the aquarium. All the species 

 are small, the biggest, the Black Goby (Gobius niger), may reach 

 5 or 6 inches, but is usually much less. Very common off 

 many parts of England is the smaller Two-spotted Goby 

 (G. flavescens). All the species are hardy in the aquarium. 



Another common fish in the rock pools is the Blenny or Shanny 

 (Blennius pholis), a small animal prettily marked with black 



FIG. 62. The common shanny (Blennius pholis). (After Day.) 



on a greenish ground, which changes in colour according to its 

 surroundings. It may be recognised by its long continuous 

 dorsal fin, which has a median depression, and by its curious 

 thick, swollen lips. It has sharp teeth, and the strong muscles 

 of the jaws enable it to tear off the shellfish, acorn-shells, etc., on 

 which it feeds. It is an active creature, swimming freely, and 

 also using its large pectoral fins (which correspond to the fore- 



