GANOID FISHES. 21 7 



the freedom of its natural habitat, and so died soon 

 after its introduction. Its successor was somewhat 

 smaller, but is alive at the time we are writing. 

 Much the same luck occurred to the first Brighton 



o 



sturgeons. This fish belongs to that ancient family 

 the Ganoids, although, unlike one division of them, 

 it is not completely clad in bony armour, but has 

 four rows running along the body, and one large ro\M 

 along the medial line. Its name of " royal " is derived 

 from an unrepealed Act of Edward II., whereby this 

 fish become the property of the sovereigns of England. 

 Like the salmon, it can live in fresh as well as salt 

 water, and, in the north, where it attains an enormous 

 size, it is usually found in the large estuarine rivers. 

 The well-known substance called " caviare " is pre- 

 pared from the roe of the sturgeon. The sterlet 

 (Acipenser rutheortis] is also exhibited at the Man- 

 chester and Brighton Aquaria. This fish was formerly 

 believed to be the young of the former, but it is now 

 known to be a distinct species. Its five rows of bony 

 plates occupy much the same position, and it also 

 resembles the royal sturgeon in its general habits. 

 This species is very common in the river Volga. 



The pipe-fishes (Syngnathidcd) have long been 

 favourites in aquaria, and some of the species are 

 kept in all our public institutions. Like their rela- 

 tives the sea-horses (Hippocampus] t the entire sur- 

 face of their bodies is covered with angular bony 

 plates, so that they can be kept without stuffing 



