30
MARINE MOLLUSCS AS HOSTS FOR SYMBIOSES
were pre-soaked for 2 h in filtered river water, blotted, and allowed to
soak overnight in the specific chemical solution. I n the second type,
referred to as " integral pyramids ", the agar pyramids incorporated
an aqueous solution of the chemical to be tested. These were not
subsequently soaked in river water.
TABLE 111. EFFECTIVENESS OF CERTAIN CHEMICALS AS ATTRACTANTS FOR
Schbtosoma mansoni MIRACIDIA
All experiments conducted in 50rnl river water except those indicated by
asterisks which were in phosphate buffer. (After MacInnis, 1965.)
Test
N o . of
Test
chemical
miracidia
chemical
cone. or p H
10
30
25
15
16
25
25
25
25
25
25
25
25
25
26
25
25
25
25
25
25
25
25
25
25
25
25
25
n-Butyric
n-Butyric
Uric
Mannose
Galactose
DL- Aspartic
DL-Valine
L-Cysteine-HC1
L- Asparagine
DL-Leucine
DL-Methionine
L-Phenylalanine
L-Histidine
L-Proline
DL-Tyrosine
Glycine
DL-Serine
L-Cystine
DL-Alanine
L-Lysine
L-Arginine
Acetic
NH, acetate
HCl
NaH,PO,
Na,HPO,
Na ,HPO
*n-Butyric
2.5 rnM
5.5 r n M
Sat. A&.
5.5 r n M
5.6 mM
1.0 r n M
1.0 rnM
1.0 r n M
1.0 rnM
1.0 r n M
1.0 r n M
1.0 rnM
1.0 rnM
1.0 r n M
1.0 r n M
1.0 rnM
1.0 r n M
1.0 rnM
1.0 r n M
1.0 r n M
1.0 m M
5.5 rnM
6.5 r n M
1-0 r n M
4.9 pH
7.0 pH
8.9 pH
6.5 rnM
25 **n-Butyric
6.5 mM
25 ***Miracidia killed
-
Controlt
-
-
Length of
exposure
(min)
Total
conlacts
Per cent
contact
with return
15
10
15
15
15
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
6
6
6
6
6
6
6
6
-
-
7
7
16
0
7
1 2
8
7
12
12
14
8
6
7
6
2
4
3
2
9
3
16
7
8
7
2
3
2
6
-
-
86
100
6
0
100
76
75
86
68
75
68
75
66
28
33
60
0
0
0
0
0
68
0
88
15
0
0
0
0
2
-
* Phosphate buffer pH 7.0. ** Phosphate buffer p H 8.9. *** Phosphate buffer pH 4.8.
t Control is the average of fifteen experiments, each for 15 min with twenty-five
miracidia in 50 ml water.