Efecte del flux d'aigua en les taxes metabòliques del cranc americà (Procambarus clarkii)

Abstract

Metabolism, which consists of different chemical reactions essential for organisms, can be altered by endogenous and exogenous factors. However, different organisms are able to adapt to these factors to achieve a constant metabolic activity. In this study, the metabolic rate (MO2) of the species Procambarus clarkii is measured indirectly from measurements of the rate of oxygen consumption at different pre-established water flows (0, 15, 25, 35 and 50 cm/s ). In addition, the standard metabolic rate (SMR), the maximum metabolic rate (MMR) were also measured, as well as the different morphological parameters that differentiate males from females and those that could influence the metabolic rates of individuals. The measurements of MO2, SMR and MMR have been obtained experimentally in the laboratory through a swimming tunnel coupled to an intermittent-flow respirometer. The "ImageJ" program has been used to measure the morphological variables from the digital photographs of each specimen. The statistical analyzes performed in this study were based on different ANOVA tests to determine if there were significant differences between males and females in relation to the standard metabolic rate, the maximum metabolic rate and their aerobic scope, since no linear regression was observed between the response variables (SMR, MMR and AS) and the covariates of total length and body mass of the individuals. On the other hand, the results of the analysis of variance of the morphological variables conclude that the most remarkable variables for the identification and distinction of males and females in the species P. clarkii are the length and width of the right cheliped. However, the different morphological features do not manifest any correlation with the physiological variables (SMR, MMR and AS), that is, with the metabolism. Finally, the study on the effect of the different water fluxes on the metabolism of P. clarkii determined that the metabolism of this species is altered according to the water flow to which the individuals are subjected, although not significant differences were observed between sexes. This fact could explain the high presence of P. clarkii in rivers of low water flow and in ponds, favoring the use of a large part of the energy for faster growth as well as greater survival and thus favoring its invasive potential