Colonization by oligochaetes (Annelida: Clitellata) in decomposing leaves ofEichhornia azurea(SW.) Kunth (Pontederiaceae) in a neotropical lentic system

Abstract

-The objective of the present study was to examine the colonization of oligochaetes during the decomposition of leaves of the macrophyte Eichhornia azurea in a lentic system in southeastern Brazil. The experiment was conducted between September and November 2007, with the use of 21 nylon bags measuring 15 r 15 cm with 2 mm mesh, each containing 10 g of dried leaves. The bags were removed from the lake after 2, 5, 8, 12, 25, 45 and 65 days. At the end of the experiment, 31.40% of the initial mass remained, and the decomposition rate was 0.018 d x1 . The mean density of oligochaetes during the experiment was 32.81 ¡ 9.58 ind.g x1 DM. The sub-families Naidinae and Pristininae accounted for 99.83% of the oligochaetes. The substrate quality influenced the colonization of E. azurea leaves, as observed from the cluster analysis by the formation of two groups based on increased density during the experiment, indicating a degradative ecological succession. During the decomposition there were changes in the community of oligochaetes, resulting from differences in the ability to exploit various food sources, with predominance of predators in the first decomposition phase and of collectors at the end of the experiment.

Aquatic oligochaeta (Annelida: Clitellata) in extractive reserve Lake Cuniã, Western Brazilian Amazon

“…Its occurrence in Brazilian aquatic environments has been registered in the States of São Paulo, Paraná, Minas Gerais, Pernambuco and Rio Grande do Sul. It also frequently lives in association with other organisms such as Nymphaea (Marcus, 1944), gastropods (Gorni & Alves, 2006), macrophytes (Montanholi- Martins & Takeda, 2001) and also to decomposing macrophyte leaves (Martins et al 2011). It has been already detected in floodplain habitats (Ragonha & Takeda, 2014), in streams of preserved areas (Rodrigues et al 2013) and in irrigated rice fields (Stenert et al 2012).…”

Inventory and distribution of Oligochaeta (Annelida, Clitellata) in first-order streams in preserved areas of the state of Minas Gerais, Brazil

“…Palavras-chave : biodiversidade, Campos Rupestres, Mata Atlântica, Naididae, folhiço, oligoquetas, Enchytraeidae. Martins et al ( , 2011 and Suriani-Affonso et al (2011), the number in the state has increased to 23. The true number is probably even higher, because ecological studies often record new species not considered in official records.…”

Chironomidae larvae associated with Eichhornia azurea leaf detritus: decomposition community structure and colonization dynamics

“…However, the methodological procedures used may have interfered with the dynamics of decomposition of E. azurea, as it was slower than in other studies Martins et al 2011;Bianchini et al 2014). Since aquatic plants generally begin to decompose at the senescence stage, part of the labile compounds may have been lost even before incubation in water (Pagioro and Thomaz 2006).…”