SALMON DISEASE IN THE EDEN. 

 By Gbokge Brook, ter. 



(Read Ylth April ^ before the Suddersfield Scientific Club.) 



A DISEASE has lately broken out in the Eden. Esk, and neighbouring 

 rivers, which has decimated the salmon to a fearful extent. When 

 seen in the water a diseased fish appears piebald and has its head 

 and, other parts covered with a thick white coat of fungus, but out of 

 the water this is not so easily recognised. When very badly diseased 

 the fish looks as if it had a thick white night-cap tied over its head, 

 the upper films of which float to and fro as the fish moves slowly in 

 the water. 



The fungus usually first appears as a small white spot on the nose ; 

 the fish then finds a still pool and usually lies near the edge of the 

 water, and after this does not move about much ; in a few days the 

 fungus spreads in a thick white coat over the head and gill covers, 

 and breaks out at the tail, fins, and any place where the skin is 

 broken ; by this time the fish can scarcely see, and the filaments of 

 fungus are so thoroughly matted together over the gill-covers that it 

 is with difficulty the fish can open its gills at all. In a few days 

 more the fish is dead. On opening its mouth you will find the throat 

 completely stopped up with fungus, and the inner surfaces of the 

 gills laced with its filaments. The blood is quite black, and it is 

 evident the fish has died from suffocation. 



This disease appears to be confined to the fresh water, though I 

 am told a fish was caught below Carlisle a few weeks ago which was 

 badly diseased and had the " sea lice " (yArgulus) on its gills. The 

 epidemic has perhaps been worst in the Esk, where the watchers 

 buried 200 salmon in one day between Langholm and Longtown, 

 aud 150 in the next two days. The fungus has spread to the smolts 

 (young salmon), trout, eels, lampreys, minnows, pike, and flounders, 

 and the fear is now that the disease may get thoroughly established 

 in the district. 



Examined with the naked eye the fungus shews itself in beautiful 

 tufts of long hair-like filaments of a slaty white appearance when 

 yotmg, which get darker as the plant grows older. Under the 

 microscope the filaments are seen to be occasionally branched, and to 

 contain a fine granular mucilage, generally denser at the edge of the 

 filaments, but occasionally clustered into minute masses scattered 



N. S., Vol. hi., May, 1878. 



