2.2. Determination of morphological characteristics
The grass carp were fasted for 17 h before anesthetizing in water
containing tricaine methanesulfonate (MS-222, 1:10,000). The total
length, body length and gut length were measured by electronic caliper.
Total length means the length from the rostral tip of jaw to the caudal
tip of the expanded tail, and body length refers to the length from the
rostral tip of jaw to the caudal end of last lateral line scale. Body weight,
hepatopancreas and gut weights were obtained with electronic balance.
Gut weight was measured after gut fat was removed and gut contents
were washed away with pre-cooled, deionized water. Data are
presented as mean ± standard error (n = 26).