Effect of a cyanobacterial diet on the competition between rotifers: A case study in Lake Albufera of Valencia, Spain
Por:
Sarma, S. S. S., Nandini, S., Miracle, M. R., Vicente, E.
Publicada:
1 ene 2019
Resumen:
Brachionus havanaensis is predominantly distributed in the Nearctic and Neotropical regions. It is now found even in the Palearctic and Oriental regions. During the summer of 2015 we found high densities (> 500 ind./l) of this species and low numbers of Brachionus angularis in Lake Albufera where the cyanobacterium (Microcystis aeruginosa) was dominant in the phytoplankton community. We hypothesized that the cyanobacterium was toxic to B. angularis but not to B. havanaensis hence the latter would outcompete the former in the presence of this cyanobacterium. To test the hypothesis, we conducted competition experiments between two coexisting rotifer species (B. angularis and B. havanaensis) from the Lake Albufera of Valencia using as food the green alga (Nannochloropsis oculata) and sonicated colonies of M. aeruginosa (single cells), separately and together (1:1 ratio based on biomass). The competition experiments using the population growth approach showed that B. havanaensis in controls had higher population abundances than B. angularis. However, when grown both together, B. havanaensis had a reduced population growth (nearly 50 %) in relation to B. angularis, in the absence of Microcystis in the diet. This reduced growth was more than that in the treatment of B. havanaensis alone when grown on a mixed diet of Microcystis and Nannochloropsis oculata. Brachionus havanaensis in all treatments (alone or in the presence of B. angularis) died completely when cultured on 100 % M. aeruginosa. The population growth rates of B. angularis, alone or in competition with B. havanaensis, were similar when Microcystis was excluded from the diet. However, Microcystis alone or together with Nannochloropsis was highly detrimental for the population growth of B. angularis. Our results showed the differences in the competitive outcome between the rotifers depending on the presence or absence of toxic cyanobacteria in the diet. Our study also showed that an exclusive diet of this cyanobacterium was toxic to both rotifers. © Asociación Ibérica de Limnología, Madrid. Spain.
Filiaciones:
Sarma, S. S. S.:
Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Av Los Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
Nandini, S.:
Univ Nacl Autonoma Mexico, Lab Zool Acuat, Div Invest & Posgrad, Campus Iztacala,Av Los Barrios 1, Tlalnepantla 54090, Estado De Mexic, Mexico
Laboratorio de Zoología Acuática, División de Investigación y Posgrado, Universidad Nacional Autónoma de México, Campus Iztacala, Av. de los Barrios #1, Los Reyes, Iztacala, Tlalnepantla, Estado de México CP 54090, Mexico
Vicente, E.:
Univ Valencia, Dept Microbiol & Ecol, E-46100 Burjassot, Valencia, Spain
Univ Valencia, ICBiBE, E-46100 Burjassot, Valencia, Spain
Dept, Microbiologia i Ecologia & ICBiBE, Universitat de València, Burjassot, Valencia 46100, Spain
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