Ritmos de actividad e influencia de las fases lunares en el cangrejo sabanero Neostrengeria Macropa (Milne Edwards, 1853) Embalse San Rafael, La Calera Cundinamarca

Abstract

Neostrengeria macropa is a species of freshwater crab, endemic to Colombia, which is of great importance in lotic and lentic ecosystems, where they accelerate the processes of organic decomposition in rivers or reservoirs, contributing to the purification of bodies of water. This research aims to characterize the diurnal and nocturnal behavior of the savanna crab, studying its relation with the physicochemical conditions of the water and evaluating if there is any effect of the lunar phases on it, in the San Rafael reservoir, Calera, Cundinamarca, Colombia, a follow-up was carried out observing, describing and analyzing the most representative behaviors of the species, in the same way to follow-up was carried out during the day and night, in the months of March - August 2015, recording each one of the activity patterns by hours. Following this, the number of active individuals was observed during the lunar phases, in the months of July - November 2015 and later they were grouped in a data sheet, finally, the physicochemical data of the water was taken to establish its relationship with the presence of the individual. For the analysis of the data, to circulate histogram was carried out for the activity rhythms, to the main component test (PCA), to poisson regression for the physicochemical data of the water and finally two Normality Test (Shapiro-Wilk and Kolmorogov-Smirnov) , a Homogeneity of variance (Levenne) test, a variance analysis test, a nonparametric Anova test and an Angular / Circular test (Watson test) to evaluate the lunar effect. According to the results obtained, the peaks of activity of the species occur in the hours of the night (7:00 a.m. to 12:00 p.m.), whose main behavior is the search for food. As for the physicochemical analyzes, it was possible to observe the crabs are more associated with bodies of water with high concentrations of oxygen, low conductivity and temperatures ranging from 13 to 17 ° C. With respect to the lunar influence on the crab, this is significant during the phase of the crescent moon compared to the full moon, New and Waning respectively. The results of this research contribute to the knowledge of relevant aspects in the behavior of Neostrengeria macropa, taking into account that studies in this species are few.