CHAPTER XIV 

 FISHES 



IN beginning with a few common and hardy shore fishes it 

 may be well to repeat that the swift swimmers among the fish 

 all require large stores of oxygen. These forms have a character- 

 istic shape of body which is readily recognised. A haddock or 

 a mackerel will illustrate this shape, and you will notice in them 

 the tapering body, the strong tail fin, the smooth scales, the skin 

 without bony plates, the flat eyes, the keel-like edge of the body 

 above and below, in general the whole structure is such as to 

 diminish resistance to swift movement in the water. Now, in 

 the shore pools at low water fish of this type are normally absent, 

 but on the other hand there may be a number of forms whose 

 shape, weak tail fins, bulging eyes, or other characters render 

 them obviously unfit for continued rapid movement in the open 

 sea, even if they can swim actively enough within the small area 

 offered by the pool. It is among these forms that success in the 

 aquarium may be hoped for, and not the least interesting point 

 about them is the way they are adapted for creeping through 

 narrow spaces in the pools, hiding beneath rocks, burying them- 

 selves in the weed or even in the sand, or attaching themselves 

 to stones to avoid being swept away by the tide. In taking home 

 specimens of these kinds of fish, however, be careful to choose 

 small examples, which are most easily kept alive. 



Quite common under weed in the tidal pools is the little 

 Father-lasher or Lucky Proach (Coitus bubalis), to be preferred on 

 account of its smaller size to its ally the sea-scorpion (Coitus 

 scorpius). The father-lasher is a little greenish fish, usually 

 only a few inches in length, with a big ugly head, a wide mouth 

 and a narrow tapering body. The head is furnished with spines, 

 and is flattened so that the eyes are on the upper surface, not 

 at the side. The operculum or gill-cover is large, and is prolonged 



