THE CERCARIAL FAUNA OF THE IRRIGATED TRACT OF THE NIZAM'S
DOMINIONS, WITH SUGGESTIONS REGARDING THEIR RELATION-
SHIP TO THE TREMATODE PARASITES IN MAN AND IN DOMESTIC
AND OTHER ANIMALS*
By G. D. BHALERAO, D.Sc., Ph.D., Research Officer (Helminthology), Imperial Veterinary
Research Institute, Izatnagar
(Received for publication on 5 March 1943)
THE present communication is the result of the
investigations carried out late in September 1941,
and in parts of July and August 1942, in the irri-
gated tract of the Nizam's Dominions. The area
extends roughly from Nizamsagar to Nizamabad
and covers a distance of about 80 miles. Al-
though the investigations extended over a period
of only five weeks during the early and late parts
of the monsoon, they yielded a number of larval
flukes which are of interest to the medical and
veterinary world. Only five species of molluscs
that occur abundantly in the area were examined.
Of these Vivipara bengalensis was found to be
quite clean, as it is in most other parts of India.
The parasites obtained from the other four species
are dealt with below. In a few cases, definite
information regarding the evolution of the flukes
was obtained, but in others it is only possible to
suggest their probable development.
FURCOCERCOUS CERCARIAE
Cercaria of Schistosoma spindalis
Liston and Soparkar [1918] worked out the life-
history of Schistosoma spindalis, a blood fluke that
occurs in cattle, buffaloes, sheep, goats and men.
Very recently the eggs of this parasite were report-
ed to have been found in the fæces of a dog in this
country. The cercariæ of this fluke were obtain-
ed by Soparkar from the molluscs Indoplanorbis
exustus and Limnaea acuminata in the vicinity
of Bombay and were studied by him in detail in
1921. The writer obtained species of this cercaria
from I. exustus in Achampet, Lingampally, Gunkal,
Ibrahimpet and Rampur; from L. acuminata in
Borlam and from L. luteola in Achampet, Ibrahim-
pet, Bodhan and Yedpally. Of the molluscs
examined at these places 4 to 70 per cent were
infected with the cercaria. At Achampet the
tank from which the snails were collected had two
of its sides enclosed but access to the rest of the
tank was free to animals. It was interesting to note
that only 5 per cent of the molluscs on the bund-
side of the tank were infected while those collected
from the rest of the tank had an infection as high
as 70 per cent.
Cercariae indicae XXX
This cercaria was originally obtained by Sewell
[1922] from I. exustus and L. acuminata in Cal-
cutta and from I. exustus in Wynaad. Rao [1934]
obtained it from L. luteola and Indoplanorbis
exustus in Madras and proved experimentally
that these are the larval stages of Schistosoma
nasalis, a parasite which produces 'snoring
disease' of cattle in this country. The writer
obtained this species of cercaria from L. luteola at
Borlam and from L. luteola and I. exustus at
Banswada.
Cercariae indicae XXV
This cercaria was first obtained by Sewell [1922
from Indoplanorbis exustus in a marshy ditch near
Rambha station, Ganjam. It is a furcocercous
cercaria of the Ocellata group. The writer obtain-
ed it from I. exustus at Borlam.
Cercaria insundlwessi Porter, 1938
This was first recorded by Porter [1938] in
South Africa from Limnaea natalensis. The
writer obtained it at Arepally in L. acuminata and
at Achampet from L. luteola. This is a furco-
cercous cercaria and represents a larval stage of
some schistosome.
Cercariae indicae II
This was originally obtained by Kemp and
Gravely [1919] from Indoplanorbis exustus at
Calcutta. The writer obtained it from the samt
host at Borlam and Yedpalli. 15 to 20
per cent of the molluscs examined were infected.
XIPHIDIO-CERCARIAE
Cercariae indicae XVII
This was originally found by Sewell [1922] in
I. exustus and L. acuminata in Mahim and in
I. exustus in Calcutta. In the Nizam's dominions
this was the most commonly occurring cercaria
and the infection of the molluscs ranged from 2 to
*Paper read before the Indian Science Congress, Section
of Medical and Veterinary Research held at Calcutta,
January, 1943.
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