196 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



DISEASED CONDITIONS OF FISHES. 

 (Plates I-III.) 



By Jas. Johnstone. 



Contents 



1. Tubercular lesions in a Cod (Gadus callarias) 



2. Ovarian Cysts in an Angler (Lophius piscatorius) 



3. Phycomycetous Fungus in a Mackerel [Scomber scomber) 



4. Fibromatous tumour from a Halibut (Hippoglossus vulgaris) 



5. Melanotic Sarcomata in Skates (Rata batis) 



6. Explanation of Plates 



Tubercular lesions in a Cod (Gadus callarias). 



A fairly large cod landed at Fleetwood in March, 

 1912, exhibited this condition. Part of the fish was 

 sent to me by Mr. T. R. Bailey, Port Sanitary Inspector. 

 The piece sent, all that behind the origin of the second 

 dorsal fin, showed that it was a spawning male in 

 apparently good condition. There were some copepod 

 parasites, Anchorella uncinata, on the vertical fins, and 

 the flesh seemed to be healthy and unaffected. 



There were numerous lesions on the skin, the tail 

 and the dorsal and ventral fins. These took the form of 

 little rounded, slightly raised, pigmented nodules in 

 the integument. They were hard to the touch, particu- 

 larly on the fins. As a rule, they occurred singly, when 

 they were about 5 mm. in diameter, and were raised 

 above the general surface of the integument about | to 

 1 mm. The pigment was sometimes reddish-black when 

 the fish was fresh, sometimes grey -black. After 

 preservation in formalin the reddish pigment disappeared 

 and all the nodules became black, particularly at their 

 margins. The central parts were sometimes creamy- 

 yellow in colour, with some very fine pigment spots 

 (see fig. 2, PI. III). 



