1-3 ^^\ 



A (I II (11 i 11 m Nil m h e r 



PREPARED BY THE ASSISTANT DIRECTOR OF THE AQUARIUM 



ZOOLOGICAL 

 SOCIETY BULLETIN 



Number J^.'! 



I'lililinlicil })// tin- Xi'-c York Zoolon-ical Socicti/ Xovfnihcr, 191/1 



ADAPTIVE COLOR CHANGES AMOXG FISHES.* 



Hi/ Dh. F. B. SriixER, 

 Director of thk U. S. Fisheriks I^aboratohy, ^^'oons Hole, Mass. 



Illustrated from photographs by Dr, Sumner. 



flexes, called forth b\- soim- distiirhancc of tlir 

 fisli, and may lie of no more ntility to the animal 

 than are blushinjj; and various other manifesta- 

 tions of emotional excitement in ourselves. 



Tlie present writer has devoted considerable 

 study to the color chanjjes of certain species of 

 flounders, with especial reference to the influence 

 of the bottom on which they lie. The most 

 striking results were obtained from a member of 

 the turbot group, lihomboidichthys podas, oc- 

 curring in the Bay of Naples. It was found 

 that this fish not only adapted itself to the gen- 

 eral color tone of the background, but to the 

 texture and pattern as well. Thus most speci- 

 mens not only assumed a very dark shade u])on 



IX the Thirteenth .hinual Report of the New 

 York Zoological Society, Dr. Charles H. 

 Townsend has described and figured some of 

 the color ciianges undergone by fishes of a num- 

 ber of species in the New York Aquarium. 

 Now, sucli changes as form the subject matter of 

 that article, although of great interest in them- 

 selves, probably Jiave no adaptive significance in 

 the majority of cases. They are nervous re- 



*The general results of these investigations were 

 presented before the American Fisheries Society, Xew 

 York, September i28, 1910. .V fuller and more tech- 

 nical account will be (lublished shortly. The studies 

 were made, for the most part, at the Xa])les Zoolog- 

 ical Station. 



PHOTOGRAPHS OF THE SAME FISH ON DIFFERENT BOTTOMS. 



