Finfish Breeding and Hatchery Management (2+1)

Stages of anaesthesia

Stage I : Total sedation – Loss of reactivity to external stimuli and slight reduction in opercular rate

Stage II : Loss of equilibrium – Fish turns over with belly on (facing up)

Stage III : Total anaesthesia – Loss of reflex activity, fish fails to respond to strong external stimuli, opercular beating almost stops.

Common anaesthetics recommended for use in aquaculture

S.No	Name	Dosage (ppm)
1	MS 222	50-100
2	Benzocaine	10
3	Quinaldine	5-25
4	Metomidate hydrochloride	5-20