Functional groups of rotifers and an exotic species in a tropical shallow lake

Marlene Sofia Arcifa,Bruno Barretto De Souza,Cyntia Goulart Corrêa Bruno,Cláudio Simões De Morais-Junior

doi:10.1038/s41598-020-71778-1

Marlene Sofia Arcifa, Bruno Barretto De Souza + Show 2 more

Open Access

https://doi.org/10.1038/s41598-020-71778-1

Copy DOI

Abstract

In freshwater environments the rotifer group may be divided into microphagous and raptorial species regarding their feeding patterns, and such guilds differently interact with other community components. Here, we analyzed the influence of cladocerans, cyclopoid nauplii, temperature, food resources and an exotic species on rotifer guilds, based on weekly samplings for 1 year. We have identified rotifer species and their trophi types in order to separate them into the raptorial and microphagous functional groups. The ratio raptorial:microphagous rotifers (Guild ratio, GR) was used in interaction analyses with cladocerans, nauplii, temperature, food resources and the exotic species Kellicottia bostoniensis. Correlations between total rotifers and food (phytoplankton carbon) and temperature were negative and significant, therefore, these factors did not lead to the increase of rotifer community. On the other hand, microphagous rotifers had opposing relation to cladoceran densities, as GR values showed that they became predominant when cladoceran populations declined. The use of density-based GR was adequate, with similar results compared to biomass-based studies regarding interactions with other organisms. Furthermore, we have found no invasive characteristics for the exotic microphagous rotifer, Kellicottia bostoniensis, and it seems to be outcompeted by the native microphagous species.

Highlights

In freshwater environments the rotifer group may be divided into microphagous and raptorial species regarding their feeding patterns, and such guilds differently interact with other community components
The significant correlation between Guild Ratio (GR) and cladocerans showed that GR, based on number of individuals, indicated interaction between microphagous rotifers and cladocerans like that reported by Obertegger and Manca[5] and Obertegger et al.[11] in temperate lakes, based on biomass (GR′)
The use of functional groups in the analysis of temporal variations of rotifers in Lake Monte Alegre proved to be valid for understanding the relationships between populations and interactions with other groups

Summary

Introduction

In freshwater environments the rotifer group may be divided into microphagous and raptorial species regarding their feeding patterns, and such guilds differently interact with other community components. The ratio raptorial:microphagous rotifers (Guild ratio, GR) was used in interaction analyses with cladocerans, nauplii, temperature, food resources and the exotic species Kellicottia bostoniensis. Measuring functional diversity means to achieve the diversity of functional characteristics, which are components of the phenotypes of organisms that influence community processes and define species by their ecological role, i.e. how they interact with the environment and other s pecies[7]. The Guild Ratio in number (GR) or biomass (GR′) can be used, which assesses the proportion of raptorial and microphagous s pecies[5,10,11].

Methods

Results

Discussion

Conclusion