DAMAGE AND RECOVERY OF ICTALURUS SP BARBEL TASTE-BUDS EXPOSED TO SUBLETHAL CONCENTRATIONS OF AN ANIONIC DETERGENT

The present work deals with the ability of catfish barbel taste buds t o recovery from exposure to sublethal doses (3 ppm) of an anionic dete rgent and the recovery time required. The barbels were taken at differ ent intervals of time starting from the moment the treated specimens w ere transferred to LAS-free water. Starting on the 6th day there is a gradual recovery of taste bud morphology. The TB recovery process appe ars to be complete at around three weeks which is in agreement with th e rapid cell turnover within the TBs and is compatible with the fact t hat LAS treatment does not appear to have altered TB nerves and basal layer. The observation that over longer periods of time (more than 42 days) the number of TBs damaged tended to increase is in agreement wit h the observation that living in aquaria has harmful effects on the fi sh chemoreceptory system. Statistical analysis of the mean percentage of damage obtained from the various experimental groups is in agreemen t with the morphological results. The results are discussed principall y in light of the data available on the damage caused by sublethal dos es of detergents in teleosts, TB regeneration in nerve resectioning ex periments and cell turnover within the TB.