The two species of molluscs experienced dieldrin amounts (relative to aldrin) of 17 - 19% (Khan et al. , 1972b). In a examine on an ostracod (Chlamydotheca arcuata) exposed to 14C-labelled aldrin (5. 5 - onze. deux µg/litre), aldrin was readily converted to dieldrin, 83% métamorphose occurring within 24 h.