265 



CHAPTER VIII. 



FRESH-WATER FISHES OF THE ORDER OF PHYSOSTOMI (continued). 



FAMILY SALMONID^E GENUS SALMO : Salmon Salmon Fisheries Salmon Disease. 

 TKOUT ; Gillaroo Salmo hardinii Sewin S. argenteus S. venemensis S. mistops 

 S. nigripinnis S. obtusirostris S. microlepis lliver Trout S. ausonii Galway Sea Trout 

 S. autumnalis S.lemanus S. carpio S. rappii S. dentex S. spectabilis S. marsiglii 

 S. lacustris S. schiffermiilleri Loch Leven Trout Orkney Trout S. polyosteus Grey 

 Trout Salmon Trout Great Lake Trout S. bailloni S. genivittatus, S. labrax. 



FAMILY: SALMONID^E. 



GENUS : Salmo (ARTEDI). 



ALL the Salmon tribe have the head naked, and the body covered with 

 scales; though in the genus Salanx, of China and Japan, which is the 

 Whitebait of Eastern seas, the scales are small, thin, and deciduous. 



The upper jaw is formed by the pre-maxillary bones in front, and max- 

 illary bones at the sides, and carries no barbels. There is always a small 

 fatty fin behind the dorsal fin. The belly is relatively wide, and more rounded 

 than in most fresh-water fishes. The intestine is generally remarkable for the 

 number of its pyloric appendages. There is a large simple air-bladder. The 

 ova fall into the abdominal cavity before they are deposited. Typical 

 Salmon, and many Trout, live part of the year in fresh water, and part in 

 the sea ; but there are many species of the genus, known as Trout and Charr, 

 which are confined to lakes and rivers. Two genera of the family, Argentina 

 and Microstoma, however, never enter rivers ; they both range from the Me- 

 diterranean to the Arctic seas, and the former at least is an inhabitant of 

 deep water. 



The genera of the Salmon tribe which are found in the fresh waters 

 of Europe are Salmo, Osmerus, Coregonus, and Thymallus, all of which belong 

 to the division of the family termed SALMONINA, in which the dorsal fin is 

 opposite, or nearly opposite, to the ventrals. 



In all species of Salmo the scales are small, and cover the body. The 

 cleft of the mouth is wide, and the long maxillary bone often extends beyond 

 the eye. The teeth are strong, and well developed, conical in form, and are 

 not limited to the jaws, but are found on the tongue, the median bone of 

 the palate named the vomer, and on the palatine bones. The short anal fin 



