214 



A HISTORY OF FISHES 



their ability to shelter within the clumps of coral or to bury 

 themselves in the coral sand. 



Mention may be made of a Chaetodont or Butterfly-fish 

 {Holacanthus semicirculatus) , in which the dark ground colour of 

 the head and body is broken up by a series of narrow curved 

 white stripes, the caudal fin being ornamented with markings 

 of a similar nature (Fig. 830). In a specimen which made its 

 appearance in the fish-market at Zanzibar these markings on 

 the fin bore a remarkable resemblance to old Arabic characters 

 (Fig. 84), reading on one side of the tail "Laillaha Illalah" 



iJl^Lii 



Fig. 84. 



Tail of a Butterfly-fish (Holacanthus semicirculatus), with markings resembling 



Arabic characters. 



(There is no God but Allah) and on the other side "Shani- 

 Allah" (A warning sent from Allah). This caused considerable 

 excitement, and the fish, which was originally sold for a penny, 

 eventually fetched five thousand rupees ! 



The most perfect examples of protective resemblance are 

 encountered among the shore-dwelling fishes living actually 

 on the sea bottom, and their spotted and mottled liveries 

 imitate the background of sand, mud, pebbles, crushed coral, 

 lava, and so on with remarkable exactitude. The Carpet Shark 

 (Orectolobus) , for example, has a beautiful, variegated coloration 

 and simulates a weed-covered rock (Fig. 82B), and many of 



