COASTLINES 



organ designed for one purpose being used for a com- 

 pletely different one : the gill-cover made for breathing 

 being employed for climbing ! 



The majority of fishes are egg-laying creatures. But a 

 comparative few are viviparous — that is, their babies are 

 born alive and not hatched from eggs previously formed 

 and shed by their mothers. Among these few, some of the 

 most notable are the viviparous blennies {Zoarces vivi- 

 parus), one or two kinds of dogfish, most of the sharks, 

 and the sawfish. 



The blennies are small fishes — the largest, Blennius 

 gattorugine, may grow to a foot in length, but this is excep- 

 tional — of which some forty species are found in the 

 northern seas, the tropical Atlantic, the coasts of Tas- 

 mania, the Red Sea, and along the coasts and shallows 

 in most parts of the world. Their elongated bodies, some 

 of which are scaleless, are remarkable for the abundance 

 of slimy matter with which they are covered. It is also 

 remarkable for the fact that it possesses only one dorsal 

 fin, which in some species is deeply divided, and for the 

 way the coastal varieties use their ventral fins as "feet" 

 to enable them to climb about among the rocks and sea- 

 weed of the shore. 



The blennies depend upon crustaceans for their main 

 food. If they are stranded on the shore by the ebb of the 

 tide they can subsist for many hours, although their out- 

 of-water endurance is nothing like that of the serpent- 

 head. Some species, however, have adapted themselves 

 to fresh water. Among these is the Blennius vulgaris, which 

 inhabits inland lakes in Southern Europe. Blennies like 

 to attach themselves to floating objects — coastal varieties 

 have been found far out at sea clinging to "rafts" of one 

 kind or another — while they will often deposit their eggs 

 in strange places and keep watch over them afterwards. 

 One species — which is not viviparous — has been known 

 to lay its eggs inside a bottle cast up on the shore, get into 

 the bottle itself, float away with it, and when dredged 



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