Biochemical parameters for Piaractus mesopotamicus, Colossoma macropomum (Characidae) ... DOI 10.526/cab.v11i2.1364363 BIOCHEMICAL PARAMETERS FOR Piaractus mesopotamicus, Colossoma macropomum (Characidae) AND HYBRID TAMBACU (P. mesopotamicus X C. macropomum) MARCOS TAVARES -DIAS 1 E FLÁVIO RUAS MORAES 2 1. Pesquisador da Embrapa Amapá. E-mail: [email protected] 2. Professor titular do Departamento de Patologia Animal da FCAV/UNESP. ABSTRACT A study for investigating the values of plasma glucose, concentrations of sodium and chloride, while P. mesopotamicus serum total protein and serum ions (calcium, potassium, magnesium, had higher concentrations of potassium and magnesium. sodium and chloride) was carried out in young Colossomoma However, levels of calcium were similar for the species studied. macropomum Cuvier, 1818, Piaractus mesopotamicus Holmberg, The hybrid tambacu showed the smallest levels of total protein, 1887 and the hybrid tambacu (P. mesopotamicus x C. macropomum), and intermediate levels of sodium, potassium, magnesium and kept in intensive system. Glucose concentrations were higher in chloride, compared to both P. mesopotamicus and C. macropomum. tambacu than in P. mesopotamicus and C. macropomum. Total Baseline values for healthy fish in aquaculture were established, protein levels were higher in P. mesopotamicus than both C. and they may be used for further comparisons in studies with wild macropomum and tambacu. C. macropomum presented higher populations of P. mesopotamicus and C. macropomum. KEYWORDS: Biochemistry, blood, Colossoma macropomum, freshwater fish, Piaractus mesopotamicus. RESUMO PARÂMETROS BIOQUÍMICOS DE Piaractus mesopotamicus E Colossoma macropomum (CHARACIDAE) E HÍBRIDO TAMBACU (P. mesopotamicus x C. macropomum) Estudaram-se os valores de glicose plasmática, proteína o P. mesopotamicus mostrou maior concentração de potássio e total sérica e íons séricos (cálcio, potássio, magnésio, sódio e magnésio. Porém, os níveis de cálcio mostraram-se similares nas cloreto) em jovens de Colossomoma macropomum Cuvier 1818, três espécies estudadas. O híbrido tambacu apresentou os menores Piaractus mesopotamicus Holmberg 1887 e híbrido tambacu (P. níveis de proteínas totais e níveis intermediários de potássio, sódio, mesopotamicus x C. macropomum), mantidos em cultivo intensivo. magnésio e cloreto quando comparado ao P. mesopotamicus e C. As concentrações plasmáticas de glicose no híbrido tambacu macropomum. Foram estabelecidos valores basais para peixes foram maiores que em P. mesopotamicus e C. macropomum. Os sadios criados em cativeiro, os quais poderão ser usados em níveis de proteínas totais em P. mesopotamicus foram maiores estudos de comparação futura em populações selvagens de P. em C. macropomum e híbrido tambacu. O C. macropomum mesopotamicus e C. macropomum. apresentou maior concentração de sódio e cloreto, ao passo que PALAVRAS-CHAVES: Bioquímica, Colossoma macropomum, peixes de água doce, Piaractus mesopotamicus, sangue. Ci. Anim., Bras., Goiânia, v. 11, n. 2, p. 363-368, abr./jun. 2010 364 TAVARES-DIAS, M. & MORAES, F. R INTRODUCTION Most commonly, the kidneys are the organs that play a major role in controlling fluid and electrolytes Interspecific crossing has been used in several fish (BALDISSEROTTO, 2002; BRAUN, 2003). However, species to increase genetic and phenotypic variation for in fish, renal function may be considered of a relatively both commercial and research purposes (CNAANI et al., minor role depending on the external environment. 2004). In Brazil, Piaractus mesopotamicus Holmberg, Thereby for many fishes, the gills, bladder and intestine 1887 and Colossoma macropomum Cuvier, 1818, both make large contributions to ionic and fluid regulation species of great economical importance originated the (BRAUN, 2003). hybrid tambacu. These fish are widely appreciated in Calcium taken up from the water in freshwater fish farming due to quick growth and weight gain, in fish follows a transcellular, hormone-controlled pathway addition to sportive and pleasure fishing. However, there located in the chloride cells of the gills. Magnesium is is little knowledge of the blood biochemical profile of an essential element for all vertebrates, indispensable these fish. for proper functioning of all cells, involved in a variety The assessments of blood biochemical parameters of enzymic reactions (FLIK et al., 1993) in intermediate are important to evaluate the health of many vertebrates, metabolism, skeletal tissue metabolism, osmoregulation, including fish (CNAANI et al., 2004; PEDRO et al., and neuromuscular transmission (LIM & KLESIUS, 2005; TAVARES-DIAS & MORAES, 2007). Since 2003). At least 80% of the magnesium required for blood and biochemical parameters in fish may vary growth and homeostasis is absorbed from the food via with ambient and other factors (BENTINCK-SMITH et intestine, while the gills contribute with less than 20% al., 1987; TAVARES-DIAS, 2004; TAVARES-DIAS & (FLIK et al., 1993). In fish, the sodium and potassium MORAES, 2004; TAVARES-DIAS et al., 2004; PEDRO are predominant electrolytes, with the predominance of et al., 2005; TAVARES-DIAS & MORAES, 2007), sodium in the serum and in other fluids and potassium they have been used by fish biologists for a variety of in extracellular fluids. The main function of proteins purposes, such as detecting cellular damage caused by and electrolytes, mainly the sodium and potassium, is toxicant exposure, infection by pathogenic agents, and to regulate the acid-basic balance maintaining thereby traumatic handling. In addition, the blood biochemical an ionic adequacy on the tissue functions (DAVIS, assessments can also be used to evaluate the effects of 2004; TAVARES-DIAS, 2004; TAVARES-DIAS et the diet on liver function, and the osmoregulatory and al., 2008). The levels of glucose and osmoregulatory ionoregulatory functions, effects of sex and maturation disturbances can be used as stress indicators in fish cycle and responses to stressors. (BENTINCK-SMITH et al., 1987; ZUIM et al., 1988; In freshwater fish, transmembrane ion gradients CNAANI et al., 2004; DAVIS, 2004; TAVARES-DIAS are the key for several physiological processes. Gill cells & MORAES, 2007). Thus, many parameters have been are exposed to different ion gradients across their apical used as quantitative indicators of stress. and basolateral surfaces as a result of their exposure In the present study it was proposed to determine to water and blood, respectively, requiring different the baselines values of plasma glucose, total protein and membrane transport mechanisms for intracellular and serum ions for P. mesopotamicus and C. macropomum blood ionic balance. Thus, when sodium concentrations and also for their hybrid, the tambacu, because are increased, potassium is generally decreased in biochemical profile of these fish when kept in intensive fish plasma or serum (FURIMSKY et al., 1999). The system has not been reported. maintenance of a consistent internal environment is essential for normal cells to function in multicellular organisms. The ionic composition of this internal MATERIALS AND METHODS environment, the extracellular fluid, must remain within narrow limits to maintain the transmembrane electrical Fish potentials of different cell types. Specialized organs and organ systems have evolved in vertebrates to carryout the Forty clinically healthy specimens of young maintenance of the homeostasis of fluid compartments. Piaractus mesopotamicus (301.5-839.0 g and 24.5-34.0 Ci. Anim., Bras., Goiânia, v. 11, n. 2, p. 363-368, abr./jun. 2010 Biochemical parameters for Piaractus mesopotamicus, Colossoma macropomum (Characidae) ... 365 cm), Colossoma macropomum (369.5-873.0 g and and potassium) and atomic absorption (calcium 26.0-37.0 cm) and hybrid tambacu (199.0-418.5g and and magnesium). Serum chloride concentration 22.0-29.0 cm) were obtained from a commercial fish was determined by the thiocynate method using a farm (21o 07’45”S, 48o03’57”W), and transported to commercial kit (Sigma 461). the Aquaculture Center (CAUNESP), Jaboticabal, São Paulo, Brazil. These fish were maintained in twelve Statistical analysis cement boxes (500 L) and acclimatized for 15 days, with controlled flow-through water system. These fish The parameters were statistically analyzed using were fed with pelleted diets (35% of crude protein) ANOVA followed by Tukey test, when the differences once a day. During the acclimatization and study were significant (p<0.05). periods the fish were observed daily for any clinical signs of diseases, including lack of appetite, increased RESULTS AND DISCUSSION opercular movements, or visible lesions of the skin, tail and fins. Signs of disease were not apparent during Biochemical parameters assessments of blood are either period of observation. The water temperature important in evaluating the fish health (TAVARES-DIAS varied from 25.1 to 29.8oC; pH 6.5 to 7.0; dissolved & MORAES, 2004; PEDRO et al., 2005; TAVARES- oxygen 5.2 to 6.3 mg/L; electric conductivity 111.6 DIAS & MORAES, 2007), in captivity or wild species. to 139.5 µS/cm. In intensive culture, osmoregulatory disturbances At the fish farm, the three species lived in similar can occur due to diseases and several other factors water conditions. This fact prevented major differences (BENTINCK-SMITH et al., 1987; STOSKOPF, 1993; in the maintenance of the fish. The P. mesopotamicus, TAVARES-DIAS, 2004). Hence, aquaculture needs C. macropomum and hybrid tambacu fry received constant accompainment