OF WASHINGTON, VOLUME 51, NUMBER 1, JANUARY 1984
on top of either the control or test agar blocks.
These data established a baseline and demonstrated that the larvae spread across the agar petri
plates randomly. (2) The difference between the
number of larvae on top of the control agar block
versus the number on top of the agar blocks with
spicule sheaths obtained from adult males taken
directly from the abomasum was significant (in
vivo). Only one-tenth of the one percent of those
larvae that entered the control agar blocks reached
the top of the blocks. About 11% of those larvae
that entered the test agar blocks were present on
top of the blocks. Many of these larvae were
curled up in the vicinity of the test preparations.
(3) The difference between the number of larvae
on top of the control and test agar blocks with
spicule sheaths dissected from adult male worms
maintained for 18 hr in vitro was not significant.
The spicules and their sheaths as well as associated debris that could not be dissected away
165
with the scalpel was called a spicule sheath in the
present paper. Each male of H. contortus had
two long spicules that could be extruded from
the cloacal opening. Each spicule had a sheath
attached to its head end that contained a fluid.
There was continuity between both the lumen of
the sheath and that of the spicule, which also had
a cytoplasmic core. The bioassay described herein
demonstrated that an attractant was present in
the spicule sheath of adult male H. contortus
grown in vivo. There was no attempt to determine if it was a general or specific attractant,
such as a sex pheromone; however, adult male
worms maintained for 18 hr in vitro lost the
capacity to attract the larvae. Furthermore, the
present study corroborated previous work (1981,
loc. cit.; 1983, loc. cit.) which indicated that nematode receptors had the ability to receive specific
chemical stimuli even as early as the infective
larval stage.
Proc. Helminthol. Soc. Wash.
51(1), 1984, pp. 165-166
Research Note
Cloacal Drop Inoculation of Trematode Larvae,
a Mechanical Aspect
WILLIAM J. BACHA, JR.
Biology Department, Camden College of Arts and Sciences, Rutgers University, 311 North 5th Street, Camden,
New Jersey 08102
The cloacal drop method of inoculating chicks
with larval trematodes has been used by Allison
(1943, Trans. Amer. Microscp. Soc. 62:127-128);
Fried and Harris (1971, J. Parasitol. 57:866-868);
Fried and Pucci (1976, Int. J. Parasitol. 6:479482); Herman and Bacha (1978, J. Parasitol. 64:
827-830); and Fried and Schnier (1981, Proc.
Helminthol. Soc. Wash. 48:83-86) among others. A suspension of free (unencysted) metacercariae or cercariae is transferred by pipette to the
cloacal lips. The mouthlike movements of the
stimulated lips draw the suspension into the cloaca.
Fried and Schnier (1982, Proc. Helminthol.
Soc. Wash. 49:151-153) have suggested that free
sterol from the bursal mucosa might serve as a
chemoattractant for Leucochloridiomorpha constantiae following per cloaca inoculation of chicks.
The present study was undertaken to determine
if entry into the bursa might also be accounted
for, at least in part, by muscular movements of
the cloaca.
A drop of suspension containing 50-60 living
cercariae, metacercariae, or heat-killed cercariae
of the marine avian trematode Himasthla quissetensis was placed upon the cloacal lips of 10day-old white leghorn chicks anesthetized with
nembutal (0.03 mg/g body wt., intramuscular).
Suspensions were in seawater (metacercariae) or
a 50/50 mixture of seawater and Locke's solution
for poikilotherms. In each instance the inoculum
was quickly ingested by the movements of the
cloacal lips and worms were recovered from the
bursa at necropsy 1 min postinoculation. The
results (Table 1) clearly indicate that movements
of the cloacal lips and adjacent musculature serve
to mechanically move an inoculum into the bursa as neither metacercariae nor dead cercariae
Copyright © 2011, The Helminthological Society of Washington
166
PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY
Table 1. Larval trematodes recovered from the bursa
of Fabricius and last 10 cm of intestine of 18 chicks
killed with ether and necropsied 1 min after per cloaca
inoculation with 50-60 living cercariae, dead cercariae
or metacercariae of Himasthla quissetensis.
Number of larvae recovered
Living cercariae
Dead cercariae
Metacercariae
Intestine
Intestine
Intestine
Bird Bursa A*
1
2
3
4
5
6
45
55
56
58
76*
91*
7
0
1
0
1
1
Bf
Bursa
A
B
0
0
7
14
19
5
9
1§
1
0
2
1
0
0
0
0
0
0
0
0
0
0
0
0
Bursa A
13
28
34
15
22
8
7
17
8
7
4
3
0
0
0
0
0
0
are capable of locomotion. The possibility that
living worms migrated into the bursa may have
contributed to the larger numbers recovered from
this group. However, differences in worm recovery from all three groups may have simply resulted from variations in body size, shape, or
consistency of the larval stages. For example,
dead cercariae are elongate and flaccid whereas
encysted metacercariae are spherical. Living cercariae contract when disturbed becoming somewhat rounded. The effectiveness of the mechanical forces responsible for propelling the worms
following inoculation may vary with such characteristics.
The fate of those worms not recovered from
the bursa or intestine was not determined.
* A = Last 5 cm of intestine.
t B = Penultimate 5 cm of intestine.
£ Bird overdosed with more than 50-60 cercariae.
§ Bird defecated shortly after inoculum was applied.
Proc. Helminthol. Soc. Wash.
51(1), 1984, pp. 166-168
Research Note
Occurrence of Leucochloridiomorpha constantiae and
Amblosoma pojmanskae Metacercariae in
the Southeastern United States
WILLIAM F. FONT
Department of Biology, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin 54701
Leucochloridiomorphid metacercariae parasitize viviparid snails in Europe, Asia, and North
America. Adults of Leucochloridiomorpha and
Amblosoma species occur in waterfowl, which
may account for the broad geographic distribution of these parasites. However, all reports of
their metacercariae in North America are from
northeastern and north-central states. This study
was made to determine whether leucochloridiomorphid metacercariae also occur in the southeastern United States.
From September 1981 to May 1982,465 snails
from four localities in Louisiana, one in Mississippi, and 12 in Florida were examined. They
included 11 species in the genera Campeloma,
Viviparus, and Lioplax. All were negative for leucochloridiomorphid metacercariae except six
specimens of V. georgianus from a single locality;
one harbored a single specimen of Leucochloridiomorpha constantiae, five harbored a total of
seven metacercariae of Amblosoma pojmanskae
(Table 1). In contrast, examination of 25 Campeloma decisum and 25 C. integrum from Wisconsin showed all specimens of both snail species
to be infected with 19-224 metacercariae of L.
constantiae per snail. Each of 12 C. decisum harbored 1-10 metacercariae of A. suwaense, and
each of four C. integrum contained one or two
metacercariae of that species. All but one specimen of A. pojmanskae from Florida exceeded
the maximum length of 1,600 /urn reported by
Fischthal for A. pojmanskae metacercariae in
New York (1974, Acta Parasitol. Pol. 22:165169). The specimens from Florida were also
Copyright © 2011, The Helminthological Society of Washington