Vol. XXIV, pp. 69-76 March 22, 1911 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



NOTES ON THE COLORATION OF FISHES! 



BY r.AKTOX A. BEAN AND ALFRED C. WEED. 

 [Published by permission of the Secretarj of the Smithsonian Institution.] 



While it is well known that the color of fishes of the same 

 species varies more or less it may not be amiss to call especial 

 attention to some of the more marked changes that may be 

 noticed. The color changes in living fishes may be due to 

 various emotions as fright, curiosity, anger, or sexual excite- 

 ment, or they may he due to environment, as the color of the 

 bottom, the color of the water, distance of the fish from the 

 surface or from bottom, distance from objects attached to the 

 bottom or floating at the surface, presence in the immediate 

 vicinity of grass, sticks, etc. 



Many people who are familiar with the fact that the color 

 and color pattern may change in the same species have an idea 

 that this takes place slowly. We hope to show that this does 

 not necessarily follow and will give some illustrations of color 

 changes which we have noted in various species in aquariums, 

 principally that of the Bureau of Fisheries at Washington, 

 D. ('. 



The Large Mouth Black Bass (Micrepterus salmoides) when 

 viewed as an ordinarily preserved specimen usually shows more 

 or less traces of a black lateral band. In the large specimens 

 this may be very faint but can usually be discerned. Similar 

 specimens of the Small Mouth Black Bass (Micropterus dolomieu) 

 show no traces of this black band but are plain olivaceous in 

 color. There are several living specimens of each species in the 

 aquarium at the Bureau of Fisheries where we have spent some 

 time watching the color changes. One large specimen which 

 showed very strongly the typical black lateral band of the Large 

 18— Proc. Biol. Soc. Wash., Vol. XXIV, 1911. (69) 



