Dwarfism Research Today is a free monthly online journal that collates and summarizes the latest research about Dwarfism, including details on genetics, diet, mental and motor development. | ||||||||
|
Morphological and cytological responses of ammonia (foraminifera) to copper contamination: implication for the use of foraminifera as bioindicators of pollution.Le Cadre V, Debenay JP Université d'Angers, UPRES-EA 2644, Laboratoire de Géologie, 2 Bd Lavoisier 49045 Angers cedex, France; LEBIM (Laboratoire d'Etude des Bio-Indicateurs Marins), 85350 Ile d'Yeu, France. val.jeje@wanadoo.fr The effect of graded concentrations of copper was analyzed at morphological and cytological levels on two species of Ammonia (foraminifera) often found in polluted areas. The two species were sensitive to low concentration, but survived high concentration (threshold value<10 microg l(-1), lethal value>200 microg l(-1)), which gives them a high potential value as bioindicators. Increasing concentrations lead to (1) increasing delay before production of new chambers, explaining dwarfism in polluted areas; (2) increasing delay before reproduction and decreasing number of juveniles, explaining low density; and (3) increasing proportion of deformed tests. Cytological modifications occurred only in deformed specimens (thickening of the organic lining, proliferation of fibrillar and of large lipidic vesicles, increased number of residual bodies). They may be responsible for anomalies in biomineralization processes. The detection of sulfur in deformed specimens suggests that foraminifers may have a detoxification mechanism with production of a metallothionein-like protein. Published 22 May 2006 in Environ Pollut, 143(2): 304-17.
© 2005-2008 Dwarfism Research Today. All Rights Reserved. |
| ||||||