Hematology of juvenile pacu, Piaractus mesopotamicus (Holmberg, 1887) fed graded levels of mannan

Abstract

ABSTRACT. Intensification of aquaculture production systems exposes fish to numerous stressors, which may negatively affect their health. This study determined the effects of increasing levels of dietary mannan oligosaccharides (ActiveMOS ® -Biorigin) on biochemical and hematological parameters of juvenile pacu, Piaractus mesopotamicus. Fish (44.04 ± 5.27 g) were randomly distributed into 24 tanks (500 L; 10 fishes per tank) and fed during 63 days with a commercial diet supplemented with 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.5 and 2.0% MOS. Blood samples were collected at 42 and 63 trial. Red blood cell count (RBC) and total plasmatic protein were affected by dietary MOS levels (P < 0.05). Fish fed 1.0% dietary MOS presented higher neutrophils numbers when compared to fish fed control diet and fish fed 1.5% MOS for 42 days presented significant higher granulocytic cell numbers. During trial fish presented increased (P < 0.05) hematocrit, mean corpuscular volume, mean corpuscular hemoglobin and plasmatic glucose concentrations and decreased (P < 0.05) RBC, hemoglobin concentration, mean corpuscular hemoglobin concentration, white blood cell and differential leukocyte count. Dietary MOS levels did not present prebiotic effects for pacu and did not minimize stress effects on hematological and biochemical parameters for the species. Keywords: Piaractus mesopotamicus, mannan oligosaccharide, hematology, nutrition, prebiotic, fish. (Holmberg, 1887) alimentado con raciones suplidas con manan oligosacáridos (MOS) RESUMEN. La intensificación de los sistemas de producción acuícola expone a los peces a numerosos factores estresantes que pueden afectar negativamente su salud. Este estudio determinó el efecto de niveles crecientes de manan oligosacáridos (ActiveMOS ® -Biorigin) en la dieta respecto a parámetros bioquímicos y hematológicos de juveniles de pacu, Piaractus mesopotamicus. Los peces (44,04 ± 5,27 g) fueron distribuidos al azar en 24 tanques (500 L; 10 peces por tanque) y alimentados durante 63 días con una dieta comercial suplementada con 0,0; 0,2; 0,4; 0,6; 0,8; 1,0; 1,5 y 2,0% de MOS. Las muestras de sangre fueron colectadas los días 42 y 63 del experimento. El recuento de glóbulos rojo (RBC) y la concentración de proteínas plasmáticas totales fueron afectados por los niveles de MOS en la dieta (P < 0,05). Peces alimentados con dieta suplementada con 1,0% MOS presentaron mayor número de neutrófilos en comparación a peces alimentados con la dieta control y peces suplementados con 1,5% de MOS presentaron alto número de células granulocíticas (SGC) a los 42 días del experimento. Durante el ensayo, los valores de hematocrito, volumen corpuscular promedio y hemoglobina corpuscular media incrementaron (P < 0,05) y las concentraciones de glucosa plasmática, hemoglobina, concentración promedio de hemoglobina, glóbulos blancos, RBC y el recuento diferencial de los leucocitos disminuyeron (P < 0,05). Los niveles dietéticos de MOS no presentaron efectos prebióticos en pacus y no minimizaron los efectos del estrés sobre los pará...

Hematological Parameters of the Hybrid Serrasalmids Farmed in Central-Western Brazil

“…The hematocrit was significantly higher in the warm season due to the significant increase in the mean corpuscular volume (MCV) of the erythrocytes in this season. Regarding patinga, the percent hematocrit observed herein was similar to those previously reported in pacu (Piaractus mesopotamicus) (Belo et al, 2014;Klein et al, 2014;Sado et al, 2014;Dieterich et al, 2015). The patinga hybrid did not show significant differences in hematocrit between the seasons, corroborating a previous study's results for the hybrid surubim (female Pseudoplastystoma reticulatum × male P. corruscans) farmed in the same region (Jerônimo et al, 2015a).…”

“…This hypothesis of parasitism would coincide with the decreased numbers of erythrocytes and thrombocytes in tambacus during the warm season. The patingas presented values of eosinophil counts within the ranges previously reported for pacu and pirapitinga (Tocidlowski et al, 1997;Sado et al, 2013Sado et al, , 2014Belo et al, 2014). No significant difference in eosinophil counts between the seasons was observed, corroborating previous results for the hybrid surubim (Jerônimo et al, 2015a).…”

“…Lymphocytes are directly involved in the specific immunological responses of fishes, and higher numbers of lymphocytes in the colder months suggest that more are needed to prevent infections then and maintain stability in these organisms (Jerônimo et al, 2011). For patinga, the amounts of lymphocytes were similar to those reported in a previous study with pacu (Jerônimo et al, 2014), and higher than those in other studies of pacu and pirapitinga (Tocidlowski et al, 1997;Sado et al, 2013Sado et al, , 2014Belo et al, 2014), without there being any significant differences between the seasons.…”

Fructooligosaccharide supplementation in diets for tropical gar ( Atractosteus tropicus ) juvenile: Effects on morphophysiology and intestinal barrier function

“…They are highly soluble in water (about 80%) and show high food stability with a pH range of 4.0–7.0 (Kumar, Sripada, & Poornachandra, 2018). Many prebiotics, including FOS, have been tested in several species such as Crucian carp ( Carassius auratus ), Pacu ( Piaractus mesopotamicus ), Caspian roach ( Rutilus rutilus ), European seabass ( Dicentrarchus labrax ), Siamese fighting fish ( Betta splendens ), common carp ( Cyprinus carpio ) and striped catfish ( Pangasianodon hypophthalmus ) with high success, improving growth, survival, intestinal morphometry and nonspecific immune response (Hoseinifar, Ahmadi, Khalili, et al, 2017; Liu et al., 2013; Sado, Bicudo, & Cyrino, 2014; Soleimani, Hoseinifar, Merrifield, Barati, & Abadi, 2012; Sutriana, Hashim, Akter, & Nor, 2018; Torrecillas, Montero, & Izquierdo, 2014; Vieira‐De Azevedo et al., 2016). This study's objective was to evaluate the partial inclusion of FOS in A. tropicus juvenile's diet on growth, survival, digestive morphology and enzyme activities, and intestinal barrier gene expression.…”