**2. Results**

## *2.1. Haematology/Peripheral Leucocyte Responses*

In experiment one, total WBC and RBC as well as MCH did not change significantly among different dietary treatments at both 1 and 2 weeks of feeding (Table 1). However, fish fed D2 presented a higher haemoglobin (Hb) concentration than D1 and D3 fed fish (Table 1). Differential leucocyte counts showed different modulation patterns between dietary treatments regardless of the sampling point (Table 2). For instance, the D1 fed group showed lower lymphocyte numbers at both 1 and 2 weeks, when compared to the other dietary treatments (Table 2). Whereas peripheral neutrophils increased in D2 fed fish compared to those fed CTR (Table 2). Circulating monocytes were not significantly modulated by dietary treatments at either 1 or 2 weeks of feeding.

**Table 1.** Haemoglobin, mean corpuscular haemoglobin (MCH), red blood cells (RBC) and white blood cells (WBC) in gilthead seabream juveniles after 1 and 2 weeks of feeding (experiment one). Data are the mean ± SEM (*n* = 12).



Different capital letters represent significant differences in time regardless of diet and between diets regardless of time (*p* < 0.05), ns (not significant).

**Table 2.** Absolute values of peripheral blood leucocytes (thrombocytes, Lymphocytes, monocytes and neutrophils) in gilthead seabream juveniles after 1 and 2 weeks of feeding (experiment one). Data are the mean ± SEM (*n* = 12).


Different capital letters represent significant differences in time regardless of diet and between diets regardless of time (*p* < 0.05), ns (not significant).

After the inflammatory insult (experiment two), Hb increased at 24 h following inoculation with the inactivated bacteria, while MCH, total WBC and RBC remained unchanged

(Table 3). Peripheral lymphocyte numbers decreased at 24 h compared to 0 h, returning to resting values at 48 h (Table 4). Circulating neutrophil levels increased at 24 h and 48 h following pathogen inoculation compared to time 0 h (Table 4). Total thrombocyte and monocyte concentrations were unaffected (Table 4).
