AILMENTS AND DISEASES 



Conclusion. There can be no question that the finely bred Gold- 

 fishes are more liable to illnesses than the ordinary breed. They are all 

 constitutionally weak and naturally subject to disturbances of digestion, 

 ailments of the swimming bladder, dropsical tendencies, and physical ex- 

 haustion; the latter due to atrophy of the muscles from disuse and from 

 having gone largely into the formation of the abnormally long and dupli- 

 cated fins, the very effort to wield which is exhausting and compels the 

 fishes to swim as much by movements of the body as of the long unwieldy 

 fins and tails. When affected by diseases these fishes are devoid of much 

 repellant, recuperative or sustaining power, as they are coddled, weakly, 

 unnatural monstrosities in whom life is kept by the constant attention of 

 the fancier. It will be noticed that it is the most highly prized fishes 

 which are most prone to illness and which soonest succumb, so that the 

 losses to the breeder are principally these and not the "sports" or partial 

 reverts. But on account of their value and the constant demand, the toy 

 varieties receive the principal attention of the skilled breeders, to which 

 must be added the fascinating uncertainty as to the result of a season's 

 labor, as any fish that hatches may possibly develop into a fine specimen, 

 if it survives. 



Although the foregoing investigations of fish diseases were conducted 

 by the author and his expert friends with aquarium fishes, the diseases and 

 remedies also apply to food fishes^ and the methods of treatment suggested 

 can be used for them as well, if modified to suit existing conditions. The 

 tenacity of life of the common goldfish is such that it is generally employed 

 for ichthiological research pertaining to diseases and their treatment. 



PARASITES AND PARASITIC DISEASES 



The diseases of fishes are both parasitic and non-parasitic. Of the 

 former, the parasites may be either animal or vegetal; which, according to 

 the parts infested, are classed as Ecto- or surface and Ento- or internal 

 parasites. It is proposed to briefly describe the common forms and 

 the more or less effectual treatment for their eradication. 



Animal Parasites and Parasitic Diseases. Nearly all classes of 

 animals include among their inferior ranks members which are either para- 

 sites or messmates at some period of their existence. True parasites are 

 those which live at the expense of their hosts, either establishing them- 

 selves in their organs and tissues or leaving them after a meal, like the 

 leech and the larvae of predatory insects; while others require this assist- 

 ance at determinate periods, either in early youth, like the young of some 

 mussels, or during the infirmities of old age, though many are internal or 

 external lodgers all their lives. Messmates are those which share in the 



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