Effects of sex and season in haematological parameters and cellular composition of spleen and head kidney of pejerrey (Odontesthes bonariensis)

Abstract

Phylogenetic diversity in fish determines high interspecific variability in morphology as well as in physiological parameters. Moreover, several haematological variables and the organ composition of haemolymphopoietic sites may vary according to sex or season. The aim of this study was to establish the haematological parameters and the cellular composition of haemolymphopoietic organs in Odontesthes bonariensis, a commercially valuable fish species in Argentina, and also to determine gender or seasonal variations. Haematocrit exhibited the highest value in summer, while haemoglobin concentration was greater in summer and autumn. Erythrocyte count was higher in spring than autumn and winter, but did not differ with summer. The increase in these variables in seasons with higher water temperatures might be a compensatory mechanism to compensate the lower level of oxygen in the environment. Leucocyte formula and blast haemolymphopoietic cells in spleen and head kidney also showed annual variations since cells related to specific immune response, i.e., lymphocytes and thrombocytes, decrease in winter, whereas cells of the non-specific immune pathways, such as granulocyte, rise. The elevation of a particular type of circulating leucocyte was preceded by an increase in values of its precursor in blood in the previous season. Both, spleen and head kidney were active in haemolymphopoiesis, although with some differences in their activity during different seasons. Males showed higher values of circulating lymphoblasts and granulocytes than females, whereas females exhibited higher values of thrombocytes. This study corroborates the high interspecific variations in haematological parameters in fish that underlines the needing of basic studies in order to assess fish health status in new promising species for aquaculture.

Hematological and serum chemistry profile in wild Pacific mackerel (Scomber japonicus) from Todos Santos Bay, Baja California, Mexico

“…In this study, WBC counts of mackerels were lower in April than those measured during August. A similar response was found in tench, sea bass, spirlin, pejerrey and Indian hill trout (Collazos et al 1998, Pascoli et al 2011, Kohanestani et al 2013, Vigliano et al 2014, Sharma et al 2017. It has been suggested that ambient changes along the year, such as photoperiod and temperature, may induce changes in the immune system.…”

“…The effects of seasonality during April and August on the mackerel were observed for blood parameters such as MCH, WBC count, total protein, globulin, glucose, and triglycerides. Seasonal variation in hematological parameters has been found in tench (Tinca tinca), sea bass (Dicentrarchus labrax), Indian carp, spirlin, pejerrey (Odontesthes bonariensis), snow trout (Schizothorax plagiostomusto), and Indian hill (Collazos et al 1998, Pascoli et al 2011, Pradhan et al 2012, Kohanestani et al 2013, Vigliano et al 2014, Sheikh & Ahmed 2016, Sharma et al 2017. Variations in hematologic parameters are due to seasonal water temperature and dissolved oxygen variations (Kohanestani et al 2013).…”

Annual changes in hematological parameters of common carp juveniles under laboratory conditions

“…In this study thrombocyte count showed the maximum in winter and minimum in summer, similarly as WBC and activity of phagocytes (NBT). Similarly maximum thrombocyte count was also observed by Gupta et al 2013and Langer et al (2013), contrary to the findings by Orun et al (2003) and Vigliano et al (2014). Stosik et al (2019) noted that thrombocytes in fish display strong defence potential which is expressed in their phagocytic activity and ability to neutralise and degrade the bacteria absorbed.…”

“…There is little information about seasonal variation in thrombocyte count in fish, and the data obtained by various authors are contradictory: increase in summer was reported by Orun et al (2003) and Vigliano et al (2014), Jeronimo et al (2011), Gupta et al (2013, while Langer et al (2013) observed maximum thrombocyte abundance in winter. Santos et al (2009) and Seriani et al (2013) found no significant seasonrelated alterations.…”

De novo Assembly and Analysis of the Chilean Pencil Catfish Trichomycterus areolatus Transcriptome

“…Though many studies do not identify significant sex differences of hemoglobin levels in fish 37 , Falahatkar et al 38 discovered decreased hemoglobin concentrations and hematological changes in juvenile Acipenser stellatus that were treated with estradiol for 7-9 months. They predict estradiol may have an inhibitory effect on erythropoiesis (the production of red blood cells).…”