Influence of Low Dietary Inclusion of the Microalga Nannochloropsis gaditana (Lubián 1982) on Performance, Fish Morphology, and Muscle Growth in Juvenile Gilthead Seabream (Sparus aurata)

Abstract

A 90-d feeding trial was conducted in which five groups of gilthead seabream (11.96 g initial body weight) were fed with a microalgae-free diet (control group, C) or four diets containing the microalgae Nannochloropsis gaditana at two inclusion levels (2.5% or 5%), either raw (R2.5 and R5 batches) or cellulose-hydrolyzed (H2.5 and H5 batches), to study their effect on the body and muscle growth. At 40 days, the highest values of body length and weight were reached in R5 group, but at 64 and 90 days, these were reached in R2.5. However, feed conversion rate, specific growth, daily intake, and survival (100%) were similar in all the groups. The acquisition of a discoid body shape was accelerated depending on the inclusion level of N. gaditana in the diets. Moreover, H5 diet affected the fish geometric morphology compared to R5 diet. The white muscle transverse area was similar in all groups at 40 days, with the exception of H2.5 group, which showed the lowest area. At day 90, C and R2.5 displayed the highest muscle growth, attributable to increased hyperplasia in C, and higher hypertrophy in R2.5. However, the highest proportion of small and medium fibers was observed in R5 and H5.

First report of interspecific transmission of sarcoptic mange from Iberian ibex to wild boar

“…This T infiltrate was also higher in wildb1 than in other wildlife species infested by S. scabiei , such as Cantabrian chamois (X 2 = 12.544, P -value = 0.0003974), red deer (X 2 = 15.53, P -value < 0.0001), wolf (X 2 = 18.491, P -value < 0.0001) and red fox ( Vulpes vulpes ) (X 2 = 19.024, P -value < 0.0001) (Fig. 8 ) [ 54 ]. Wildb1 total B (X 2 = 39.962, P -value < 0.0001) and plasma cells (X 2 = 35.042, P -value < 0.0001) were also higher than in chamois.…”

“…On the other hand, the wildb1 macrophage values were lower than in wolf and red fox (X 2 = 11.255, P -value = 0.000794) (Fig. 8 ) [ 54 ]. Altogether, the pathological findings indicate that wildb1 had an ordinary scabies reaction type (adaptive immune response), which coincides not only with the cell type infiltrate, but also with the macroscopic lesions, the low number of mites found and the self-limiting nature of S. scabiei infections usually described in interspecific cross-transmissions.…”

“…Additional paraffin 3-µm sections of the wildb1 and control wild boar skin samples were made for immunohistochemical analyses through specific staining to detect inflammatory cell types, namely macrophages, plasma cells, T cells and B cells. Immunohistochemical laboratory procedures were performed following the methodology described by Martínez and collaborators [ 54 ], allowing comparison with previously reported findings (Additional file 1 : Table S1).…”

“…Eosinophils, mast cells, macrophages, plasma cells, T cells and B cells were counted at ×400 in five fields of each respective skin section staining from each wild boar (wildb1 and the control one), following the previously reported methodology [ 54 ]. The mean proportion of stained cells to total cells was averaged across the five fields.…”

New Stable Cell Lines Derived from the Proximal and Distal Intestine of Rainbow Trout (Oncorhynchus mykiss) Retain Several Properties Observed In Vivo

“…However, the ability of alternative diets to replace increasing amounts of their fish-based counterparts in carnivorous fish species has been limited by adverse responses, often species-specific, that depend on the nutritional- and anti-nutritional characteristics and dietary inclusion levels of different ingredients. This difficulty not only impairs feed efficiency, but also compromises animal welfare, causing severe gastrointestinal pathologies that include diarrhea [ 4 ], decreased nutrient absorption [ 5 ], intracellular lipid accumulation [ 6 ], gastric bloating [ 7 ], intestinal inflammation [ 8 ], and cancer [ 9 , 10 ]. The current lack of mechanistic knowledge of the cellular and molecular mechanisms that determine the adverse reactions of the fish intestinal epithelium limits our capacity to support the development of effective alternative diets.…”