NATURAL HISTORY. 



FIFTKEN-SPDfJJD STICKLEK.U K. 



Iii Great Britain there are two fresh-water species, the Three-spined Stickleback and the Tinker, or 

 Ten spined Stickleback, and one marine species, the Fifteen-spined Stickleback. 



The Three-spined Stickleback (Gasterosteus aculeatus) is so named from having three spines. 

 in the middle of the back, in the position usually occupied by the first dorsal fin. The body is 

 moderately elongated and compressed ; the ventral fins have one strong spine ; the middle of the body 

 is covered with plates, but there are no scales. It is a furious fighter, but, as is so often the case 

 in the animal kingdom, the females are peaceful, and it is only the males \vho do battle. These 

 fishes are remarkable for their parental instinct, which leads the male to build a nest and watch 

 carefully over the young. The nest is made of stalks of grass and other substances, which are 

 cemented together with mucus, either from the mouth or from the skin. The bottom of the nest 

 is first laid, and afterwards the sides and top are built. According to Signer Costa, as quoted by 

 Yarrell, a small hole is left on one side of the nest. The colours of the male now become ex- 

 tremely brilliant. After a good deal of coaxing he drives the female into the nest. She makes 

 her way out on the opposite side of the nest to that by which she entered, leaving the eggs behind, 

 The male fertilises the eggs, and is said to frequently bring to the nest a succession of females. 

 He then watches for a month over the nest, which is about the size of a shilling, or a little larger, 

 and is placed at the bottom of the stream in about six inches of water. The eggs are of a bright 

 yellow colour. The length of this species rarely exceeds three inches. In some parts of the country, 

 when abundant, the fish have been collected for manure. They live from two to three years. Yarrell 

 mentions that in Kamschatka and Rupert's Land they are stored as winter food for dogs, that hogs 



