Item description  File or link to file  File type
 Location of fish sampling stuff (PIT tags, syringes etc)  DownstairsLab  pdf
 Guidelines for use of MS-222 (e.g. buffering)  Guidelines_for_the_Preparation_and_Use_of_MS222_Feb14_Final  word


Anesthesia procedures – Liliana García Lago

Anesthesia procedures are the same every time a fish is weighed, measured, fin-clipped or stomach flushed. Anesthesia is necessary to reduce stress of the fish during handling. Each fish would be anesthetized only once. Fish are collected and store in a bucket with clean water. After that, they are lightly anaesthetized in a 70 mg/l solution of buffered MS-222 (be careful, because with small fish such as those we had at the sampling (4-5 cm length) that concentration was enough to kill them…so after the first day, we used half of that concentration). After weight and measure the fish, it is then put into a recovery bucket which has stream water at ambient temperature and some rocks for enrichment. The fish is allowed to recover for 30 minutes to an hour, or longer if necessary. The procedure (measure, weigh, fin clips and stomach flush) takes at most 3 minutes, and the fish is dipped back into stream water between each step (approx. every 30s).

If a fish is injured or distressed, it is kept in a perforated bucket in the stream, with cover and substrate for 2 hours so that it can recover. If a fish has not recovered in this time (I.e. is having difficulty maintaining equilibrium, or not breathing) it will be euthanized (140 mg/l buffered MS222)”.

Name of Drug: MS-222 (tricaine methane sulphonate)

Dosage: Buffered

Volume: 70 mg/l

Route: Immersion