Biochemical-functional differences between reproductive and non-reproductive males of Procambarus clarkii (Girard, 1852)

Abstract Intermediate metabolism and oxidative balance markers help to better understand environmental dynamics and how they influence the physiological patterns of organisms. Procambarus clarkii (Girard, 1852), a crayfish native to the United States of America and Mexico, represents an appealing case study for understanding invasive species’ metabolic dynamics. This species has sexual dimorphism and two male morphotypes: reproductive (M1) and non-reproductive (M2). We evaluated the seasonal variations of biomarkers in M1 and M2 males, collected in each season of 2016 at Parque Alfredo Volpi (São Paulo, Brazil). Hemolymph, hepatopancreas and abdominal muscle samples were extracted to determine markers of intermediate metabolism, oxidative balance, the hepatosomatic index and the stomach repletion degree. The results showed differences between the two male morphotypes. M1 showed a predominance of medium to full stomachs throughout the year, with an allocation of energetic substrates mainly used in reproduction (gametogenesis and reproductive behaviors). They also presented increased lipoperoxidation, SOD and GST activities. M2, on the other hand, had a lower capacity to allocate energy reserves in the period leading up to and during reproduction, which may be associated with a lower degree of gastric repletion. However, M2 maintained alternating antioxidant strategies that helped preserve low levels of lipoperoxidation in the hepatopancreas throughout the year. This pattern observed for the degree of gastric repletion indicates an intraspecific competition between the categories of males, which, together with the profile of energy reserve usage, seems decisive for M2 to reproduce.