Ecological and life history traits have been used to understand the basic ecology of fishes. This study aimed to examine the existence of plasticity in life history traits of populations of Hollandichthys multifasciatus in ten blackwater streams. This is an inseminating Characidae, endemic to the Atlantic coastal drainages of Brazil. Different aspects of the life-history of the species, such as mean length, sex ratio, absolute and relative fecundity, gonadosomatic index, condition factor, length-weight relationship and the growth parameter (b) of 185 specimens were studied during the period of low precipitation (June-September). Fish samples were obtained along a 100 m stretch of each stream, and some habitat variables recorded. ANOVA and Kruskal-Wallis tests indicated a similarity in most of the analyzed traits, with exception of the mean length of immatures, Gonadosomatic Index of mature males and condition factor of immatures and mature adults. Also, slope tests of the length-weight relationship were significantly different for immatures. The observed differences were attributed to heterogeneity in food availability and/or other site-specific factors, which may influence growth and/or breeding aspects among the studied localities. The approach used herein may improve understanding of trait plasticity under natural conditions, helping to understand fish-community responses to anthropogenic changes.

The canidae are a family of the Mammalia class represented by two extinct subfamilies called Hesperocyoninae and Borophaginae. Also by the still existing subfamily called Caninae which includes all living canids (dogs, wolves, jackals, coyotes and foxes). Divided into 14 genus and 34 species distributed on all continents. They have carnivorous and omnivorous feeding, being pack animals or essentially solitary animals meeting only during the breeding season where many species develop parental care for their offspring. Among these species the maned wolf (Chrysocyon brachyurus) stands out. Being the largest South American canid an omnivorous, generalist and opportunistic species whose diet varies seasonally consuming a great diversity of fruits and small vertebrates. They are widely distributed in the areas of fields and savannahs in the central region of South America. However it is noted that there was a considerable decrease in the original portion of their habitat in addition to the illegal hunting to use the animals' fur being run over on roads and diseases are the most frequent causes that do not contribute to the conservation of this species. Therefore the species is listed in Appendix II of CITES and is considered Vulnerable (VU). As Chrysocyon brachyurus represents one of the main predators of its biome playing a fundamental role for its balance. Its preservation is essential and further studies are needed for better understanding and formation of strategies that contribute to its conservation.

It corrects the article: http://doi.org/10.11606/1807-0205/2020.62.016