Interaction of pH with mercuric chloride toxicity to penaeid prawns from a tropical estuary, East Coast of India: enhanced toxicity at low pH
Toxicity tests were conducted to study the interaction of pH and the response of two size groups of penaeid prawns i.e. Penaeus monodon and Penaeus indicus to different sets of five concentrations of HgCl 2 (0.01–0.09 mg l −1) under a broad range of pH conditions (5–9). Behavioural responses varied...
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Published in | Chemosphere (Oxford) Vol. 58; no. 9; pp. 1241 - 1248 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.03.2005
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Toxicity tests were conducted to study the interaction of pH and the response of two size groups of penaeid prawns i.e.
Penaeus monodon and
Penaeus indicus to different sets of five concentrations of HgCl
2 (0.01–0.09
mg
l
−1) under a broad range of pH conditions (5–9). Behavioural responses varied according to test solution concentration and nominated values of pH. Abnormality was detected in the higher concentrations with lower pH in smaller size group of
P. monodon. High mortality was observed at higher concentration of test solution with low pH. Irrespective of species and size group LC
50 demonstrated similar trend of variation with respect to time period. At pH 9 the threshold limit for 65–75
mm size group of
P. monodon and
P. indicus was 0.043 and 0.049
mg
l
−1 respectively while it was 0.041 and 0.035
mg
l
−1 respectively at pH 8; and 0.038 and 0.044
mg
l
−1 respectively at pH 7. Relative toxicities were significantly varied except for bigger size groups in the studied pH ranges. The result was pronounced at pH 5 with maximum 1.61 times for inter-hour relative toxicity in contrast to all. At pH below 7 of mercury resulted more toxic compared to high pH range (>7) might be due to acid toxicity itself. At each pH smaller size groups were sensitive while bigger shown tolerant.
P. monodon were more sensitive than
P. indicus. The toxic order of pH effect was 9
<
8
<
7
<
6
<
5. Toxicity increased significantly (
p
>
0.01) in acidic medium compared to alkaline. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0045-6535 1879-1298 |
DOI: | 10.1016/j.chemosphere.2004.09.088 |