FISHES AND MANKIND 4^5 



and multiply rapidly. When these tumours burst, the parasites 

 arc disseminated in the water, and the resulting ulcers are 

 attacked by fungus. . 



The fungus mentioned above (Saprolei>nia Jerax) is not m 

 itself a specific disease, but only makes its appearance on 

 individuals weakened by other maladies, or those whose vitality 

 has been lowered by unhealthy conditions, pollution or by the 

 effort of the reproductive act; it nearly always attacks hsh with 

 bruises, wounds, or abrased surfaces, on which the spores 

 floating in the water are able to obtain a hold. Once established, 

 the roots or rhizoid portions of the fungus penetrate into the 

 living dssues of the vicUm, and commencing with a small 

 infecdon on the site of an injury, it spreads like leprosy over 

 the whole body, fins, eyes, gills, and other parts, until death 

 supervenes. It attacks young and old fish alike, and the spores 

 may lodge on dead or unferdlised ova, and from thence spread 

 to healthy eggs. Examined under a powerful lens, the fungus 

 may be observed to have the form of numerous fine filaments 

 projecting from the surface of the skin, while to the naked eye 

 the growth has the appearance of fine cotton-wool. It is 

 particularly prevalent among fishes kept in small ponds and 

 aquaria, but also attacks those living in a wild state. 1 he most 

 sadsfactory remedy lies in dipping the infected individuals in 

 salt water (one ounce of common or rock salt to a gallon ot 

 water) or into a mixture of permanganate of potash (Condy s 

 Fluid) and water of a deep claret colour, wiping off the visible 

 growth with a swab of cotton wool. Other remedies which 

 have proved fairly successful include paraffin oil, kerosene, 

 formalin, carbolic acid, copper sulphate, lime and boracic acid, 

 but it depends largely on the condidon of the fish whe^er it 

 be killed or cured by such drasdc treatment. It is not sufficient 

 to remove the fungus from the fish themselves, but the receptacle, 

 whether bowl or pond, must also be treated with one of the 

 above-mendoned fungicides to avoid the danger of re-infection. 

 In the case of aquaria or cement basins this can be done without 

 difficulty, but where the fishes are living in natural ponds or 

 large stretches of water the complaint is very much harder to 

 eradicate. Complete disinfecdon of the whole pond, followed 

 by a period of some weeks or months during which the water 

 is allowed to lie fallow, provides the only hope of a permanent 

 cure. The matter is really one of prevention rather than cure, 

 for in nearly every case of a severe epidemic it can be shown 

 that the general hygiene of the pond is at fault. 



