1915. | T. SOUTHWELL: IJndtan Parasites of Fish. 329 
(10) Syndesmobothrium filicolle, Linton, parasitic in the 
flesh of Harpodon nehereus (‘‘ Bombay duck ”’’) 
from Diamond Harbour. 
(Plate xxvii, fig. 8). 
Z.E.V. £882 Flesh of Havpodon Diamond Harbour,  T. Southwell. 
nehereus. 17-ii-IQ15. 
The original description of this parasite was given by Linton 
in the Report of the Commissioner of Fish and Fisheries for 1887 
(published 1891, Washington), page 861, plate xv, figs. 2 and 4. 
The description was from a single specimen and the details given 
are so meagre that the identification of the parasite is attended 
with a little uncertainty. The adult form was obtained by 
Linton from the spiral valve of Trygon centrura at Woods Hole, 
Mass. Encysted forms were also obtained by Linton from various 
species of Teleosts such as Pomatomus saltatrix, Cybium regale, etc. 
The present writer also obtained the same parasite on the 
Ceylon Pearl Banks from the intestines of Cybium guttatum (Seer 
fish) and Chorinemus lysan (Southwell, Ceylon Marine Biological Re- 
ports, Part VI, page 269, plate ii, figs. 16 and 17. Colombo, 1912). 
The flesh of Harfodon nehereus (when alive) is transparent, 
resembling that of a jelly-fish. The cysts being milky-white were 
easily discernible with the naked eye. Many cysts were 16 mm. 
long and the smallest obtained was 4 mm. They were all roughly 
tadpole-shaped, but the ‘‘ tail’’ portion varied greatly in length 
and thickness. When removed, the cyst moved about actively. 
The parasite itself could be seen under a low power as a more 
densely milk-white spot in the head of the cyst. Over 80 cysts were 
taken from the flesh of a single fish which measured 34 inches long. 
Harpodon nehereus was very plentiful in the river between 
the sea and Diamond Harbour; in the vicinity of the latter place 
it was scarce and ten miles further north entirely absent. Every 
fish caught was infected. As far as I am aware, this is the first 
record of a cestode parasite occurring in the flesh of any fish, east 
of Suez. The parasite becomes adult in the larger species of 
Trygon and Hypolophus. In other words when rays and skates eat 
the infected Bombay duck, the larval parasites in the latter be- 
come adult tapeworms in the intestines of the rays. The parasites 
do not inhabit the human intestine and hence there is not the 
slightest danger of human beings becoming infected by eating the 
infected fish. 
Diamond Harbour is on the river Hughli and is situated 
about 40 miles from the sea. 
LITERATURE. 
Linton.—Notes on entozoa of Marine fishes. Report U.S. Fish 
Comm. for 1887, pp. 862-866, plate xv, figs. 5-9. Washington, 1891. 
Southwell.—Ceylon Marine Biological Reports, Part VI, page 
273, plate ii, fig. 40. Colombo, I9g12. 
