Relationship among carnivorous macrophyte Utricularia foliosa L. and species composition and life forms of periphytic algae community

Relação entre macrófita carnívora Utricularia foliosa L. e a composição de espécies e formas de vida da comunidade de algas perifíticas

Abstract

Aim

Present study evaluated the life forms and taxonomic structure of the periphytic algae community on Utricularia foliosa L. (modified leaf and stem) and artificial substrate during the four seasons in a tropical shallow reservoir.

Methods

We evaluated the periphyton on natural and artificial substrate in order to evaluate the influence of substrate type on the taxonomic structure of algal community. Monospecific stands of U. foliosa were selected. Water and periphyton sampling were performed within U. foliosa stands in the autumn (April/2010), winter (July/2010), spring (November/2010) and summer (February/2011). Nylon thread was used as the artificial substrate. The community structure was evaluated through life forms, species richness, diversity and species composition.

Results

Species diversity was significantly different only among seasons. The life forms and species richness were different between substrate types and seasons. Entangled filamentous algae had higher biovolume in the periphyton on artificial substrate and unicellular flagellated algae had higher biovolume on natural substrate. Species composition changed among the seasons and species descriptors differed among substrates types. Species-level taxonomic classification responded clearly to the substrate type.

Conclusions

We concluded that the taxonomic structure and life forms of periphytic algae on artificial substrate poorly represented the natural periphyton on U. foliosa. The type of substrate strongly influenced the periphyton–Utricularia relationship.

Keywords:
life forms; artificial and natural substrates; species composition; shallow reservoir