CH. VI MABINE FAUNA OF TALIS8E SHORES 115 



blue shot with pink on the ventral surface and the fins. 

 When removed from the water it seemed to me that the 

 colours faded almost more rapidly than those of other reef 

 fishes ; whether this is a sign that the ostracions are able 

 to change their colours during life with greater rapidity 

 than other coloured fishes, I am unable to say. 



A very instructive series of investigations might be made 

 by some naturalist in the tropics upon the powers that the 

 reef fishes possess of changing their colours. It is well 

 known that trout, minnows, and many other English fish 

 do considerably alter in appearance when placed amid 

 different surroimdiugs. It would be very interesting, then, 

 to see how far or how rapidly the bright red, blue, and 

 yellow spots and stripes of these tropical fishes are capable 

 of altering when keptahve under more sombre circumstances 

 than the Hfe amid the gay colours of the coral reefs. Such 

 experiments, I am afraid, can only be made on some well- 

 fitted vessel where a constant supply of fresh sea-water 

 can be kept running through the aquaria. 



A large blue sting-ray {Aetobatis ?) was given to me by 

 a sailor soon after I arrived in Talisse. He had caught 

 it while fishing off the pier. It came as a timely warning 

 never to attempt to wade upon the reef with naked feet, 

 for the large, serrated, stinging spine on its taU looked 

 capable of inflicting a very dangerous wound. Its back 

 was covered with large round patches of a dull prussian- 

 blue colour. This was the only elasmobranch fish I obtained 

 during my stay in the tropics. 



I must now leave these brightly-coloured fishes of the 

 reefs. It would serve no useful purpose for me to attempt 

 to give in this volume a complete list or description of the 

 varieties of the fish of Celebean waters. Those of my 

 readers who are particularly interested in the subject will 

 find a very complete account of the ichthyology of these 



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