Freshwater sponge-dwelling Chironomidae (Insecta, Diptera) in northeastern Brazil

Abstract

The Neotropical region possesses a rich freshwater sponge fauna; however, knowledge about its taxonomy and the community inside the sponges remains fragmentary. Chironomidae (Insecta, Diptera) larvae associated with freshwater sponges have been largely reported in literature and some genera are recognized as containing species exclusively dependent on these organisms. In this study, we analyze the occurrence of chironomid larvae associated with freshwater sponges (Spongillidae) in northeastern Brazil. Samples were collected in two aquatic systems in Pernambuco, Brazil, in February 2011 and October 2012. In the Rio Sirinhaém, Corvoheteromeyenia australis (Bonetto & Ezcurra de Drago) was the only sponge collected, and Polypedilum Kieffer, Goeldichironomus Fittkau, Xenochironomus Kieffer and Cricotopus Van der Wulp were the chironomids found as its associated fauna. On the other hand, in a fishpond, Heteromeyenia cristalina Batista, Volkmer-Ribeiro & Melão, Radiospongilla inesi Nicacio & Pinheiro and Tubella variabilis Boneto & Ezcurra de Drago were the collected sponges, and Polypedilum, Chironomus Meigen, Dicrotendipes Kieffer and Goeldichironomus were the larvae associated with these species. Although only species of Xenochironomus are reported to have close interactions with freshwater sponges, herein we document other Chironomidae genera associated with these organisms. Nevertheless, further investigations are needed to better understand how chironomid larvae use sponges as shelter and/or to avoid predation in a facultative way. The objective of the present study was to analyze the occurrence of Chironomidae inhabitants of freshwater sponges in aquatic systems in the state of Pernambuco, in order to contribute to the knowledge of sponge-dwelling chironomids in northeastern Brazil.

Keywords

• Aquatic insects
• Interspecific interaction
• Porifera
• Sponges
• Neotropical