Can thrombocytes participate in the removal of cellular debris in the blood circulation of teleost fish? A cytochemical study and ultrastructural analysis

Comparative study on hematological parameters of farmed matrinxã, Brycon amazonicus Spix and Agassiz, 1829 (Characidae: Bryconinae) with others Bryconinae species

“…Mechanisms of specific immunity in fish, similarly to lower vertebrates, are significantly less developed and play markedly less important role than in birds or mammals (Stosik et al, 2001;Tavares-Dias et al, 2007). In contrast, fish have non-specific resistance system, which plays the basic role in the organism defense against pathogenic and environmental factors (Stosik et al, 2001;Passantino et al, 2005).…”

“…A characteristic feature of fish is the wide physiological range of blood parameters and also the great individual variation (Tavares- Dias et al, 2003;Kori-Siakpere et al, 2005;Tavares-Dias and Moraes, 2007), which has been attributed to factors such as genetic variation, nutritional status, sex, age, stress due to capture, handling and sampling procedures (Tavares- Dias and Moraes, 2004;Kori-Siakpere et al, 2005). In B. amazonicus from the present study, among red blood cell parameters, the red blood cell counts, hemoglobin concentration and hematocrit have lower intraspecific variation.…”

“…Hematological parameters of various farmed fish species have been investigated aiming to establish baseline values (Ranzani-Paiva, 1991;Guijarro et al, 2003;Tavares-Dias and Moraes, 2004;Kori-Siakpere et al, 2005;Tavares-Dias and Moraes, 2007), in addition to identify disturbances caused by parasitic infections (Tavares- Dias and Moares, 2004). Interspecies variations in red blood cells parameters have been attribute to many internal and external factors (Tavares- Dias and Moraes, 2004;Tavares-Dias and Moraes, 2006a) such as the quality of the aquatic environment, season, sex, age, nutritional status, stress due to capture, handling and sampling procedures and water temperature (Ranzani-Paiva, 1991; Guijarro et al, 2003;Tavares-Dias and Moraes, 2004;Kori-Siakpere et al, 2005).…”

“…In the fish circulating blood besides mature cells there are also blastic cells and maturing cells of particular development lineages (Tavares- Dias and Moraes, 2004;Tavares-Dias and Barcellos 2005;Tavares-Dias, 2006;Tavares-Dias and Moraes, 2007). Thus, this inconsistency in cell nomenclature and appearance has lead to confusion regarding the identity of some cells in Bryconinae species.…”

“…The hematological profile of a fish population could indicate its physiological status and health and in this way hematology combined with other routine diagnostic methods could be used to identify and assess conditions that cause stress to the fish and, consequently, disease (Tavares- Dias and Moraes, 2004;Tavares-Dias and Moraes, 2006a;Tavares-Dias and Moraes, 2007;Pavlidis et al, 2007). Red blood cell parameters can be used for the diagnosis of anemia while the leukocytes, the primary line of immunological defense, provide an important representation of defense cells throughout the body (Tavares- Dias and Moraes, 2004;Tavares-Dias and Moraes, 2007;Affonso et al, 2007;Pavlidis et al, 2007). Thus, one of the most elementary ways to assess the immune system is to explore changes in the number or appearance of fish circulating white blood cells (WBC).…”