Kelthane residues in tissues of the tropical penaeid prawn, Metapenaeus monoceros (Fabricius), under sublethal chronic exposure--a monitoring study.

Monitoring the biodegradation and bioaccumulation of kelthane residues were undertaken during reclamation through oxygen consumption (respiration) and target enzyme activity assays. Even after 30 days of reclamation, non-recovery in respiration and target enzyme assays revealed the accumulation of kelthane as a residue in tissues. Thin-layer chromatography demonstrated the presence of kelthane residues as spots in tissue extracts of midgut gland and muscle after a 30-day recovery period. This confirms that kelthane is a persistent insecticide of low biodegradability and capable of accumulating in tissues as residues even at sublethal concentration under chronic exposure.