Ecology and life-history of Mesonauta festivus: biological traits of a broad ranged and abundant Neotropical cichlid

Abstract

The cichlid Mesonauta festivus is common and abundant among macrophyte stands along a large geographical range of the Amazonas and Paraná-Paraguay basins, in South America. This broad geographical range highlights the species' dispersion ability, which can be attributed to specific biological and behavioral traits. However, the dispersion ability does not account for the broad geographical range alone, as the species must be able to establish populations in a range of environments, which include marginal areas of large rivers with different water types, floodplain lakes, and small terra-firme streams. In this work we investigated the specie's ecology, biological traits and behavior in order to understand what and how its traits may have allowed it to attain such broad geographical range and aid in establishing local populations. Regarding its dispersion ability we stress the capability of swimming in the pelagic region, which is remarkable for this species and uncommon among Neotropical cichlids. Its vagility is high even when juveniles are under parental care. Regarding population establishment, the high environmental tolerance stands out, allowing the species to live under strikingly different abiotic conditions. In addition, the small size of first sexual maturation and its capability of spawning along the whole hydrologic cycle (apparently not associated to a specific environmental cue) may also facilitate the establishment of populations into new environments. Moreover, the behavior of mimicking dead leaves, which is mainly performed by juveniles, may lessen predation pressures. Under an ecoevolutionary perspective, the traits highlighted in this work may buffer selective pressures experienced by populations in different biotic and/or abiotic conditions, which may also favor the increasing of the geographical range by allowing the evolutionary lineage to remain similar even in disconnected and/or striking different environments.

Simultaneous abrupt shifts in hydrology and fish assemblage structure in a floodplain lake in the central Amazon

“…In the laboratory, each specimen was identified, measured for standard length (SL, mm), weighed (g) and examined to determine sex and reproductive status according to criteria described in ref. 44. Dietary analysis was based on frequency of occurrence and relative volume of food items in stomachs (detailed methods in ref.…”

Amazon fish bacterial communities show structural convergence along widespread hydrochemical gradients

“…Here we investigated the bacterial communities (gut and skin mucus) of two ecologically and phylogenetically divergent host species (flag cichlids, Mesonauta festivus; and black piranhas, Serrasalmus rhombeus) distributed throughout these hydrochemical gradients (Pires et al, 2015;Van der Sleen & Albert, 2018).…”

“…Here we investigated the bacterial communities (gut and skin mucus) of two ecologically and phylogenetically divergent host species (flag cichlids, Mesonauta festivus ; and black piranhas, Serrasalmus rhombeus ) distributed throughout these hydrochemical gradients (Pires et al, ; Van der Sleen & Albert, ). The main objective of our study was to characterize Amazonian fish microbiota variations across multiple scales: among different species, different tissues, from both water colours and from replicate collecting sites within each water colour.…”

Reproductive life-history strategies in a species-rich assemblage of Amazonian electric fishes

“…Moreover, no studies have to date explored variation in life history across environmental gradients within a sympatric monophyletic group of closely related Neotropical fish species. Our understanding of comparative life history biology in the world’s most diverse aquatic vertebrate fauna is consequently limited [2, 10].…”