94 



inconvenience. There is, however, a Crustacean {Meineriia 

 imhricaia which often brings about fatal results, not only in 

 this fish, but in many others. The John Brown, on which 

 the above observation was made, became subsequently 

 duller in colour, less lively and seemed in distress. When 

 taken out of the tank and examined, the cause was found 

 to be the presence of this parasite. A simple operation was 

 sufficient to remove it and the fish immediately recovered. 



The eggs of this fish are of the usual pelagic type, small, 

 transparent and floating. 



It is usually ready to take any sort of food offered it, though 

 it seems particularly fond of " red bait." 



The Hottentot {Cantharus hlochii C.V.). 



This fish, like the Galjoen and John Brown, is provided with 

 sharp, cutting teeth. It is of a dark sometimes bronze colour, 

 to which it doubtless owes its local name. It is one of the most 

 common-place fishes both in appearance and behaviour. It 

 usually becomes a very light colour in the white-tiled tank, 

 though, like the Galjoen, it occasionally becomes very dark. 



In the case of this fish and also of another (the Bamboo-fish) 

 a diseased condition was occasionally observed, caused appar- 

 ently by a Protozoon. The fish got in low condition and small 

 specks appeared over the body and fins. These could be 

 readily examined microscopically by transmitted light in the 

 fin. The largest were easily visible to the naked eye and con- 

 sisted of a ciliated body much laden with granules, of a spheroid 

 shape, but provided with a protrusible mouth part, which, as 

 the animal revolved in the cavity in which it was contained, 

 was applied to the surrounding tissue. The affected fish often 

 recovered, but occasionally died apparently from the parasites 

 affecting the gills. This parasite seemed different from any 

 of the described Protozoan parasites of fishes. 



The Steenje {Cantharus emarginatus). 



This is a lively little fish, and lives well in the aquarium. 

 It is somewhat of the same colour as the Hottentot. It is 

 mentioned especially on account of certain observations which 

 may have some bearing on change of colour. It is more 

 gregarious than the Hottentot, and a group of about half a 

 dozen in the tank usually kept together. Sometimes, how- 

 ever, two fish were found, not far from each other, remaining 

 almost stationary, but with the tips of the fins keeping up an 

 active movement, while the colour of the body became abnor- 



