THE NATIONAL GEOGRAPHIC MAGAZINE 



Photograph by Dr. W. H. L,ongley 



PANIC UNDERSEAS 



This wonderful photograph was taken, not in an aquarium tank, but about eight feet 

 under water in the Gulf Stream, with an especially designed camera. Posing for their 

 portraits are gray snappers, yellow goatlish, grunts, a parrot-fish, and a schoolmaster, 

 nocturnal fish, which, as a rule, rest quietly all day. The seeming confusion is due, however, 

 to the presence in their neighborhood of a barracuda, that veritable tiger of the warm seas 

 and the natural enemy of all small fish. 



through which it swims, the Yellow Tail's 

 bright yellow tail probably makes a shin- 

 ing mark, though its colors otherwise are 

 well calculated to give it a low visibility. 

 Are we to conclude from this that there 

 are no larger fishes which prey on it ? 

 No; there pretty surely are such fishes, 

 though it may well be so swift as to es- 

 cape many which would otherwise do so. 



DEEP SWIMMING FISH ARK OFTEN RED IN 

 COLOR 



As regards concealment, having a yel- 

 low tail must be a disadvantage to it, 

 and is a character which would doubtless 

 have been lost in the keen competition of 

 the tropical waters where it lives, were 

 there not, on the other hand, some com- 

 pensating advantage. It may be a badge 

 of identification, useful to a school in 

 keeping together. 



It has been previously mentioned that 

 the Red Snapper comes from deeper 

 water than other common snappers. 

 There is a tendency for fishes which 

 swim deep down under the blue or green 

 sea and yet within the range of surface 

 light penetration to be red in color. A 

 great many are not, to be sure, but a 

 larger proportion are red here than else- 

 where, frequently a clear bright striking 

 red all over. 



It seems almost a pity that the light 

 in which they live is so green that the 

 color, red, must appear an intangible 

 neutral gray ! Perhaps it gives them a 

 useful inconspicuousness down there, or 

 perhaps it absorbs a maximum amount 

 of the dim, strongly blue-green sunlight, 

 which is in some way beneficial. 



One of the commonest species of the 

 surface reefs, the Squirrel Fish (Plate I), 



