Tagging: on the use of passive integrated transponder (PIT) tags for the identification of fish

To determine the efficacy of passive integrated transponder (PIT) tags for marking rohu Labeo rohita (Ham.) in the selective breeding programme, a ser ies of experiments has been carried out at the Central Institute of Freshwa ter Aquaculture (CIFA) under the Indo-Norwegian project of 'Selective breed ing of rohu'. Six groups of rohu fingerlings with weight ranging from 2 g t o 20 g were tagged with PIT tags to determine a suitable size range for tag ging. Fingerlings weighing 8-15 g were found to be quite suitable for taggi ng with a PIT tag. Recovery of the PIT tag depends upon the survival of tag ged fish under field conditions. Rejection of the PIT tag by rohu was obser ved to be only 0.05%. Through effective management practice, the survival o f tagged fish increased up to 95%, and thus tag loss was minimized.