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Color Changes of the Chub-sucker 



CARL L. HUBBS 



Field Museum and Chicago Aquarium Society 



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 i 



Young Chub-sucker (Erimpzon sucetta), snowing full complement of color markings 



A well-known ichthyologist tells of an 

 interesting experience which once befell 

 him while collecting fishes on the reefs 

 of Panama. Among numerous other 

 gaudily marked little fishes he obtained 

 one which he wished to observe further. 

 This fish he placed in a brightly tinned 

 rail. Returning an hour or so later, he 

 was surprised to find what appeared to 

 be a different fish, pale and plain in color. 

 Leaning over to obtain a closer view he 

 chanced to touch the edge of the pail ; 

 in an instant the whole color pattern of 

 the little fish was displayed in all its 

 former conspicuousness. I have had 

 somewhat similar experiences on the 

 reefs of California. Certain sculpins, 

 caught there in the deeper algae-filled 

 tide-pools, were found to be almost uni- 

 form blackish in color ; when placed in a 

 light sandy pool or held in my hand they 

 brought out on their bodies, before my 

 astonished gaze, a pattern of black and 



white almost as contrasting as the ink 

 and paper on this page. 



Anyone favored with a normally 

 curious frame of mind, upon seeing such 

 color changes exhibited by fishes, would 

 inquire into the significance and the 

 causes of the phenomena. A search 

 through fish literature reveals quite 

 a number of articles dealing with 

 this subject. Would it not, however, 

 prove far more entertaining and instruc- 

 tive to study the problem independently, 

 by direct observation of the changing 

 coloration of some suitable aquarium 

 fish, and then compare our results with 

 those that others have obtained and 

 written of ? 



For a few weeks past I have kept a 

 young chub-sucker (Erimyzon sucetta), 

 a neat little fish of our own creeks, in a 



* With five original drawings from nature 

 by Leon L. Pray, Field Museum of Natural 

 History. 



