Abdominal dissection

This is a dissection experiment on immature oceanic pink salmon.

It will be explained in detail that the measurement of liver and gonad weights, counting of the pyloric caeca, and observation of gastric contents to confirm nutrition and maturity status with an abdominal dissection.

HSI (Hepato Somatic Index) refers to “the percentage of liver per body weight of an individual”.

It generally increases before the spawning season. It is also sometimes used as an indicator of maturity, since it is known in some fish species that HSI decreases as GSI increases, as the liver sends accumulated nutrients to the gonads.

HSI = (liver weight [g] / body weight [g]) *100

GSI (Gonado Somatic Index) refers to “the ratio of gonads per body weight of an individual”.

It is often used to estimate the reproductive cycle of fish and as an indicator of maturity, and some fish species have been associated with HSI.

GSI = (gonads weight [g] / body weight [g]) *100