Studies on Luminescence in Marine Snails 
Y. Haneda 1 
Among the Gastropoda Opisthobranchiata 
certain genera of the Polyceridae, Tethyidae, 
and Phillirhoidae are luminous. Among the 
Gastropoda Pulmonata two luminous species 
are known: Latia neritoides, fresh water limpets, 
first discovered in New Zealand by Suter 
(1890), and Dyakia striata, land snails, found 
by myself in Singapore in 1946. 
Luminous species of Gastropoda Proso- 
branchiata are very rare, however, according 
to E. N. Harvey in his book Bioluminescence 
(1952). Turner in 1948 informed him by letter 
that Tonna galea Linne, a marine snail, is 
luminescent. When this snail moves through 
water with its foot well extended, it emits a 
greenish-white light. A species of doubtful 
luminescence is also found among the hetero- 
pods (Pterotracheata) according to Keferstein 
in Bronn’s Tierreich (1862-1866). 
We have found two species of luminous 
marine snails on Borawazawa Beach, at Suye- 
yoshi Village, which is located on Hachijo 
Island, 157 miles south of Tokyo. This dis- 
covery was made during ebb tide on April 23, 
1953. While I was strolling on the beach with 
an acquaintance, Mr. H. Okuyama, teacher 
of Suyeyoshi Primary School, he chanced to 
raise a stone, and we were both astonished 
to find under it some small marine snails 
which were emitting light as they rolled in 
the water. Excitedly we collected many speci- 
mens, examining them closely to find out if 
1 Yokosuka City Museum, Yokosuka, Japan. Man- 
uscript received November 16, 1956. 
these marine snails were really luminous, or 
whether their luminescence was due only to 
their having eaten some luminous matter or 
to infection with luminous bacteria. 
As a result of subsequent experiments, I 
decided that these snails were true luminous 
animals, possessing luminous organs on their 
mantles (Haneda, 1955). 
During a trip to the Luminescence Con- 
ference at Pacific Grove, California, for the 
meeting of March 29-April 1, 1954, I had 
the opportunity to continue my studies of 
these interesting animals. I collected another 
species of luminous snails on Waikiki beach, 
Oahu, and one other species on Onekahakaha 
beach, Hawaii, and on the beach at Key West, 
Florida (see Haneda, 1955). 
ACKNOWLEDGMENTS 
To the following people I must express my 
sincere gratitude and appreciation: To Pro- 
fessor S. Hatai, chairman of the Committee 
on the Research of Marine Resources, spon- 
sored by the Japanese National Commission 
for UNESCO, for having given me the oppor- 
tunity to carry out this present work; to 
Professor E. Newton Harvey of Princeton 
University and Professor Bernard L. Strehler 
of the University of Chicago, both of whom 
gave me much instructive advice; to Dr. I. 
Taki of the National Science Museum in 
Tokyo, and to Mrs. Anna Harris of the Ber- 
nice P. Bishop Museum in Hawaii, both of 
whom identified the specimens of Planaxis; 
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