Seasonal variations in the cellular composition of haemolymphopoietic organs of silverside (Odontesthes bonariensis).

CATTANEO, E.; MARENGO, M.; ARAUJO, A.; MARCACCINI, A.; VIGLIANO, F.A.

Rosario, Argentina

Congreso; I Congreso Argentino de Ciencias Morfológicas Veterinarias; 2009

Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario.

In fish, high interspecific variations in the cellular composition of haemolymphopoietic organs and, consequently, their capacity to develop a particular immune response have been reported. Therefore, the aim of this study was to establish the cellular composition of head kidney (HK) and spleen (S) of adult silverside (Odontesthes bonariensis) ?an Argentinean native fish of great commercial value- by means of smear analysis in each season. In both organs the forerunner cells of erythrocytic [erythroblasts (Eb), proerythrocytes (Pe)], lymphocytic [lymphoblasts (Lb)], granulocytic [granuloblasts (Gb), progranulocytes (Pg)] and monocytic [monoblast (Mb)] lineage were observed. The %EbHK and %PeHK remained stable along the year, whilst %EbS showed its highest level in winter and %PeS was significantly lower in summer and autumn than in winter and spring. The highest %LbHK was in summer while %LbS showed two seasonal peaks in summer and autumn. In relation to granulocytic lineage, %GbHK, after its highest value in autumn, fell in winter together with a significant increase in %PgHK in winter and spring. The %MbS was significantly higher in winter than in summer, whilst %MbHK was higher in winter than in the other seasons. In line with these cell variations, previous studies indicate that at low temperature an inhibition of the specific immunity and a stimulation of non-specific immune process occur. Moreover, our findings suggest that in silverside both organs are active in haemolymphopoiesis, although with differences in their ability through the year.