THE FRESH-WATER AQUARIUM. 



19 



account of these combative proclivities it should be kept 

 by itself — that is, so far as other species of fish are con- 

 cerned. But if it be the only finny denizen of our 

 artificial pond, its interesting habits and movements will 

 more than repay for the lack of variety in species. The 

 juvenile angler calls the male fish a "red-throat," on 

 account of the rich tints of crimson and green he assumes 

 in spring-time. At this period the pugnacity of the 

 species is exhibited in a very marked degree. Curiously 

 enough, it is the habit of Sticklebacks to construct nests 

 for the proper protection of their eggs during the period 

 which elapses between laying and hatching. This nest 

 is constructed of weeds and grass, somewhat tubular, 

 open at both ends. In this a large number of eggs are 

 deposited, and it becomes the duty of Mr. Red-throat to 

 guard this nursery from the depredations of his kindred. 

 It must be conceded that he discharges the duties of his 

 trust faithfully, for presently we observe a marauder 

 prowling about in search of dainties in the shape of 

 Sticklebacks' eggs. The guardian of the nest prepares 

 for action, and elevating his back spines and sticking out 

 those on his sides, rushes upon the intruder. The battle 

 has now commenced in earnest and continues to rage 

 until one falls lifeless to the bottom, his belly ripped open 

 by his adversary's sharp spines. Sometimes, however, it 

 does not terminate so fatally. One of the combatants 

 feeling that the battle is not with him, and that " discre- 

 tion is the better part of valour," slinks off, a sadder and 

 a wiser fish, but "lives to fight another day." A small 

 worm dropped into the vessel containing these fish will 

 afford considerable amusement. It will be quickly seized 

 by one individual who will rush to the other end of the 

 tank with it, followed closely by a pack of his relatives, 



