Table 1 Average histological scores from ten fish in each group, scored from 0–3 (none, mild, moderate, or severe) in heart and red muscle in G1 and G2 from sampling IV-XI (August 2020-May 2021)

G1

1

1

1.4

1.6

0.9

0.8

0.6

0.8

G2

1.5

0.1

0.2

0

0

0

0

0

Red muscle

*IV

V

VI

VII

VIII

IX

X

XI

G1

0.2

0.9

0.75

1.4

0.5

0.9

0.5

0.5

G2

0.2

0.1

0.3

0.1

0.1

0.1

0

0