Toxicity of kelthane to eyestalk ablated and eyestalk extract injected penaeid prawn, Metapenaeus monoceros (Fabricius)

The neuro-endocrine system present in the eyestalks of crustaceans was involved in moulting, growth, metabolism, development and physiological processes. The toxicity of the organochlorine pesticide kelthane to prawns (Metapenaeus monoceros) from which the eyestalk had been removed and to prawns with the eyestalk removed but which were then injected with eyestalk extract was investigated. The 96 h LC50 values (calculated by 5 different methods) for both types of experimental animal and for the controls are tabulated. The chemical was more toxic to prawns with the eyestalk removed than to those injected with eyestalk extract or to the controls; this was attributed to the loss of certain hormones.