Deep-Sea Fish with Lanterns 



Some fish carry their own power plants, searchlights, 

 lenses and dimmers as if they were living automobiles 



By Dr. E. Bade 



Illustrations by the Author, supplied by Courtesy 

 of American Museum of Natural History 



Some deep- sea fish are equipped with headlights 

 which look very much like those on an automobile 



DEEP-SEA fish have been strangely 

 influenced by that total darkness 

 in which they live. Their eyes 

 have lost their responsi\'eness to light and 

 are therefore 

 practically 

 sightless. 

 These blind 

 fish are the in- 

 habitants of 

 those profound 

 depths into 

 which not even 

 an infinitesimal 

 ray of light can 

 penetrate. In 

 fact the fish 

 must live in 

 perpetual dark- 

 ness. The eyes 

 of some deep- 

 sea fish are 

 tiny; the eyes 



of others are very large and round, as if 

 they would catch some faint ray which 

 may by some chance have penetrated 

 these depths. But the most pecuUar 

 thing about the deep-sea fish is that ap- 

 proximately one fifth of 

 them have developed 

 some kind of a luminous 

 organ, carried on this or 

 that part of the body. 

 Yes, even the whole 

 body of some of the fish 

 is illuminated, giving 

 off to the surrounding 

 water a faint iridescence 

 as they glide along. 



It's Deep Where They 

 Live 



Such lights are found 

 not only on deep-sea 

 fish, but on some varie- 

 ties that live in well- 

 lighted parts of the 

 ocean as well. 



Two small varieties, commonly called 

 "lantern fish," inhabit the Malay archi- 

 pelago about the Banda Islands. A 

 third variety has recently been discovered 



near Jamaica. 

 These three 

 forms are the 

 only ones upon 

 whom the ac- 

 tion of the 

 organ of light 

 can be o b- 

 served under 

 normal condi- 

 ti o n s . The 

 large, luminous 

 organ, situated 

 just below the 

 eye, emits a 

 greenish - white 

 light, which is 

 not steady but 

 which flickers 

 rhythmically. By pushing or pulling a 

 skin over this organ the fish prevents all 

 rays from escaping outward. 



The light-organs of deep-sea fish are 

 similar in structure. They were in all 



Other deep-sea fish have their bulbs, resembling portable 

 electric lamps, attached to the tip of a long, movable stem 



358 



