io6 



again taken up and the whole process is repeated several 

 times. This was the only evidence of playfulness observed 

 in any of the fish. 



Healthy fish generally keep the surface of their body scrupu- 

 lously clean and sometimes effect this by rubbing on rocks or 

 on the sand. Klip-fish, for instance, may be frequently seen 

 progressing along the bottom of the tanks by what appears a 

 series of somersaults, evidently for this purpose. The Harders 

 in the tank seldom came to the bottom, and they found rubbing 

 posts on the spines of the dorsal fins of their fellows. Thus one 

 of a group of Harders was occasionally seen dashing about in 

 the shoal skimming over the backs of the other fish to their 

 evident discomfort. As it passed over their broad dorsal 

 spines it turned on its side, which was then dragged quickly 

 over their hard edges. A peculiar habit of the South African 

 mullets (Miigil constantia\ the " springer ") may be mentioned 

 here. It is found chiefly in the rivers, and, in many parts 

 of Cape Colony and Natal, it is the custom to catch this 

 fish by going out at night with a light in the boat. The 

 fish jump into the boat of their own accord — one of the 

 simplest and easiest methods of fishing known. 



The Maasb anker {Trachurus trachurus, Lacep). 



These fish, apparently identical with the " Horse-mackerel "' 

 of Europe, were occasionally kept alive in the tanks. Small 

 specimens, about three or four inches in length, did fairly well 

 in captivity. They are lively little fish and generally get their 

 fair share of food, and that by a peculiar device. As is well 

 known, they have a row of large scales along each side of the 

 tail, and these are provided with sharp spines so as to form a 

 rasp-like organ. The Dasjes also are always in evidence when 

 there is any food about, and the curious spectacle was some- 

 times seen of these small fish driving off the larger Dasjes by a 

 very quick movement, somewhat similar to that noted above 

 in the case of the Harders, the sharp spiny scales being drawn 

 rapidly over the side of the Dasje, which at once fled and,, 

 although it made several cautious attempts to approach the 

 food, was as often driven off. Ultimately it made off promptly 

 whenever the Maasbanker approached the neighbourhood. 



The young of this fish are said to seek shelter under the 

 tentacles of Medusae. 



Klip-zuiger or Sucker-fish {Chorisochismus dentex, Pall.). 



The habits of this fish are peculiar and recall those of the 

 Remora. Its one object seems to be to fasten on to some- 



