The main objective of this study was to examine the effects of a plant protein- vs. fishmeal-based diet on growth response in a population of 24 families, as well as expression of growth-related genes in the muscle of adult zebrafish ( Danio rerio ). Each family was split to create two fish populations with similar genetic backgrounds, and the fish were fed either fishmeal (FM diet) or plant protein (PP diet) as the unique protein source in their diets from 35 to 98 days postfertilization (dpf). To understand the effect of the PP diet on gene expression, individuals from three families, representative of the mean weight in both populations, were selected. To understand the effect of familiar variation on gene expression, the same families were evaluated separately. At 98 dpf, growth-related genes Igf1a , Igf2a , mTOR , Pld1a , Mrf4 , Myod , Myogenin, and Myostatin1b were evaluated. In males, Myogenin , Mrf4 , and Igf2a showed changes attributable to the PP diet. In females, the effect of the PP diet did not modulate the expression in any of the eight genes studied. The effect of familiar variation on gene expression was observed among families. This study shows that PP diet and family variation have effects on gene expression in fish muscle.

The mission of veterinary clinical pathology is to support the diagnostic process by using tests to measure different blood biomarkers to support decision making about farmed fish health and welfare. The objective of this study is to provide reference intervals (RIs) for 44 key hematological, blood biochemistry, blood gasometry and hormones biomarkers for the three most economically important farmed salmonid species in Chile (Atlantic salmon, coho salmon and rainbow trout) during the freshwater (presmolt and smolt age range) and seawater stages (post-smolt and adult age range). Our results confirmed that the concentration or activity of most blood biomarkers depend on the salmonid species, age range and/or the interaction between them, and they are often biologically related to each other. Erythogram and leukogram profiles revealed a similar distribution in rainbow trout and coho salmon, but those in Atlantic salmon were significantly different. While the activity of the most clinically important plasma enzymes demonstrated a similar profile in Atlantic salmon and rainbow trout, coho salmon demonstrated a significantly different distribution. Plasma electrolyte and mineral profiles showed significant differences between salmonid species, especially for rainbow trout, while Atlantic salmon and coho salmon demonstrated a high degree of similarity. Furthermore, electrolytes, minerals and blood gasometry biomarkers were significantly different between age ranges, suggesting a considerably different distribution between freshwater and seawater-farmed fish. The RIs of clinically healthy fish described in this study take into account the high biological variation of farmed fish in Chile, as the 3.059 individuals came from 78 different fish farms, both freshwater and seawater, and blood samples were collected using the same pre-analytical protocol. Likewise, our study provides the Chilean salmon farming industry with standardized protocols that can be used routinely and provides valuable information to improve the preventive vision of aquamedicine through the application of blood biomarkers to support and optimize health, welfare and husbandry management in the salmon farming industry.