Journal of Environmental Biology

Ciliates and trophic state: a study in five adjacent

urban ponds in Mexico City

A. Lugo-V?zquez¹*, M. R. S?nchez-Rodr?guez¹, J. Morl?n-Mej?a¹, L. Peralta-Soriano¹,

E. A. Arellanes-Jim?nez², M. A. Escobar-Oliva², and M.G. Oliva-Mart?nez²

¹Proyecto de Investigaci?n en Limnolog?a Tropical, FES Iztacala, Universidad Nacional Aut?noma de M?xico (UNAM),

Av. de los Barrios No. 1, Los Reyes Iztacala, Tlalnepantla, C.P. 54090, Estado de M?xico, M?xico

²Carrera de Biolog?a, FES Iztacala, UNAM, Av. de los Barrios, No. 1, Los Reyes Iztacala, Tlalnepantla, C.P. 54090, Estado de M?xico, M?xico

*Corresponding Author E-mail: lugov@unam.mx

Key words

Ciliate biomass

Eutrophic conditions

plankton

protozooplankton

shallow lakes

Publication Data

Paper received : 16.07.2016

Revised received : 08.05.2017

Re-revised received : 07.06.2017

Accepted : 03.07.2017

Abstract

Aim: The ciliated protozoa are components of the microbial food web. A relationship between species richness, number, and size of ciliates, and the trophic state has been recognized in some works. The aim of this study was to determine how the trophic differences affect the protozooplankton composition, abundance, and biomass considering the similarity in location and climatic conditions in five adjacent shallow urban water bodies in Mexico City with differences in trophic state.

Methodology: Monthly protozooplankton samplings were conducted from January to December 2015 and measured water temperature, dissolved oxygen, specific conductance, pH and Secchi disk, RDP, TP, and chlorophyll a.? Integrated column samples for ciliates were obtained and taxonomic richness, species density, and biomass by size class calculated using in vivo, stained and Lugol fixed samples. ANOVA was applied for environmental data comparison, and cluster analyses were carried out using environmental and biological data. A redundancy analysis was used to explain the variation of the ciliates biomass related to physicochemical conditions.

Results: Ciliate densities and biomass varied accordingly with the trophic state and showed higher values in the more productive ponds, and lower values in the other ponds. Oligotrichia and Prostomatea were the dominant taxonomic groups. Eastern Quarry ponds trophic state varied from oligotrophic to near hypertrophic and abundance and biomass variation of planktonic ciliates followed a trophic gradient, showing higher values in more eutrophic systems. Ciliates in the range body size of 30-50 ?m dominated the biomass in the ponds. An unexpected result was the low species number and densities of the small size ciliates (mainly Scuticociliatida) that often are important in eutrophic conditions.

Interpretation: The relationship between the trophic state and the abundance and biomass of plankton ciliates was confirmed. The size fraction < 20 μm was not important, and the 30-50 μm body size ciliates were dominant even in the most productive ponds.

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