84 Pub. Puget Sound Biol. Sta. Vol. 2, No. 37 



the same surroundings, but this was not found by the writer. Those few 

 eases which seemed to be exceptions, or to be on the borderline, were 

 considered as unusual or as "strays." Blennies, bright green in color, 

 were taken from eelgrass (Zostera) almost exclusively; while rare, de- 

 cidedly red forms were taken only from water around red algae beds, where 

 little red light penetrates. Here crabs and other forms were also red. 



During several weeks no change was noted in differently colored indi- 

 viduals confined in the same live-box with common food and background. 

 If adaptive color-changes occur in blennies they would seem to be ex- 

 tremely slow in the adult forms. 



Resistance and reactions to temperature changes 



Blennies are sometimes subjected to greater ranges in temperature 

 than other marine fishes. In determining comparative resistance, "rat- 

 tail" (Xeneretmus alaskanus?) and cottid {Icelinus borealis) fishes, from 

 a depth of 60 to 100 meters, were compared with blennies from the shore 

 belt. Several individuals were placed in pans and the temperature 

 raised 1° C. at the end of each 10-minute period by pouring in hot water. 

 A control pan with water at only a little above sea temperature was used 

 to check other conditions. 



The results were striking. The fish from 60-100 meters in no case 

 survived above 23.5° and died between 22.5° and 23.5°. The blennies 

 died between 26° and 29°. In 2 experiments most of the blennies died 

 near and below 27°; in 1 experiment, in which the temperature was raised 

 gradually at the rate of 1° C. every 3 minutes, half the individuals were 

 alive at 28°, and 1 individual after remaining for some time at 29° revived 

 when the water cooled. 



During these experiments the movements and general state were care- 

 fully noted and recorded. Ordinarily the activity of the fishes decreases 

 as the temperature rises above the optimum. This is true in general of 

 the blennies but with modifications worthy of mention. These fish nor- 

 mally lie motionless much of the time, against the bottom of some sub- 

 merged object. These periods are followed by other periods of rapid 

 movement abruptly terminated. Like other fishes, they are more actively 

 responsive to stimuli at low temperatures, and as the temperature rises 

 are more sluggish in individual movements. However, when the optimum 

 is much exceeded the periods of rest and activity disappear and the total 

 amount of movement is increased. The fish, now in constant motion, 

 listlessly visits every corner and object possible. The movement becomes 

 slower, with increasing temperature, until complete torpor precedes death. 



Some attempts were made to determine the reaction and degree of 



