CHAETODONTIDAE [Butterfly fish) 



ACANTHURIDAE [Surgeon fish) 



One of the most interesting of the numerous species of 'coral 

 fish' found in the madreporic waters of the Red Sea and 

 tropics is the group of the chaetodonts (butterfly fish) . The 

 mild or even high temperature of the Water which allows 

 the florid development of many species of madrepore and 

 coral is a conditio sine qua non for the existence of these fantastic 

 highly-coloured fish. The fish of the genus Chaetodon of the 

 Chaetodontidae family are usually flat in a lateral direction 

 and ne^'er very big. Their fins are so extended that the 

 dorsal, caudal and anal fins appear to be all of a piece. 

 Sometimes the dorsal and anal fins of this genus end in a 

 thread-like appendage. Their colouring varies from species 

 to species in an infinite range, from red to bright yellow, 

 from green to pure indigo, spread all over the body in 

 straight or wavy lines, in big or small round patches, and in 

 horizontal or vertical bands on the snout, like a mask. They 

 have been appropriately called butterfly fish because of this 

 colouring and because of their habit of fluttering around, 

 generally in pairs, near the varicoloured masses of madre- 

 pore. I confess that the duty of capturing these gorgeous 

 creatures did not come easily to me. 



Surgeon fish are common in the same environment and 

 equally wonderful in shape and colour. They are dis- 

 tinguished by one or more sharp cutting spikes fixed on the 

 caudal peduncle facing towards the head. I do not know the 



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