CALORIC CONTENT OF MUSCLES FROM Prochilodits lineatus (CHARACIFORMES, PROCHILODONTIDAE) IN THE MANSO RESERVOIR, BRAZIL

With the objective of finding intraspecific variations in muscle caloric content of Prochilodus lineatus, 118 specimens were analyzed from October 2002 to September 2003, at the Mans Reservoir; Mato Grosso, Brazil. From each individual, morphometric measurements were obtained, sex and stage of gonadal maturity identified, and muscle samples extracted from base of the dorsal fin. Five samples from different regions of the musculature were taken fawn 18 resting females in order to verify the existence of caloric differences within the same individual associated to muscle regions. All samples were dried in a laboratory oven at 60 degrees C to constant weight, macerated, homogenized and set to burn in a bomb calorimeter (PARR). Significant variations were not detected among the different regions of the musculature or between sexes. Among reproductive stages, significant differences were recorded only for females, and the resting stage was significantly different from the others. For males, the muscle samples presented a higher caloric content during the maturation stage than in other stages. The correlation analysis between standard length and caloric content of muscles of females indicated a difference for individuals in the resting stage. Among males, the correlation, although low, was significant for immature individuals, as well as during resting and maturation stages. The present study corroborates the importance of considering caloric variations by body length class and emphasizes the relevance of understanding the energy changes resulting from gonadal maturation.