Short Communication |
Corresponding author: Thais Giovannini Pellegrini ( thais.g.pellegrini@gmail.com ) Corresponding author: Leopoldo Ferreira de Oliveira Bernardi ( leopoldobernardi@gmail.com ) Academic editor: Oana Teodora Moldovan
© 2017 Bárbara Goulart Costa, Thais Giovannini Pellegrini, Leopoldo Ferreira de Oliveira Bernardi, Rodrigo Lopes Ferreira.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Costa BG, Pellegrini TG, Bernardi LFO, Ferreira RL (2017) Notes on predator-prey relationships among Tanypodinae larvae (Diptera, Chironomidae) and mites (Acariformes) in Brazilian subterranean aquatic environments. Subterranean Biology 22: 67-74. https://doi.org/10.3897/subtbiol.22.13925
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Chironomidae larvae and mites are abundant and diversified groups that coexist in several environments. However, little importance has been attributed to their ecological relationships (predator–prey, parasitism, etc.). Therefore, the present study aimed to report the predation of mites by Tanypodinae larvae in Neotropical quartzite caves.
Gut content, cave; interaction, predation
Chironomidae represents an abundant and diverse family of the order Diptera. Its larval forms are one of the most important groups of aquatic insects, representing an abundant part of the fauna present in lake and river biotopes (
Independent of their habitat, chironomid larvae play an important role in the trophic chains of aquatic communities (
Studies have highlighted that Tanypodinae larvae show a well-defined food preference, mainly consuming larval forms of other Chironomidae species (
Although some studies have reported this trophic interaction between mites and Tanypodinae (e.g.,
For this purpose, the specimens were collected across eight sampling events (from June 2013 to January 2014). The study area comprised three subterranean allogenic streams that run through the following quartzite caves: Mandembe cave (21°32'38.1"S, 44°47'57.3"W), Serra Grande cave (21°33'33.5"S, 44°49'10.7"W), and Toca cave (21°28'24"S, 44°40'02"W), all of which are located in southern Minas Gerais, Brazil. Specimens were collected along a 100-m stretch of each stream divided into 11 transects, with three replicates per transect, using a Surber net of 400 cm2. Tanypodinae larvae were separated from other organisms and mounted on slides using Hoyer medium. The predator and prey specimens were identified using an optical microscope ZEISS Primo Star, with identification keys presented by
The gut content of 287 Tanypodinae specimens collected across all sampling events were analyzed; only seven of them had preyed on mites (Figures
These results suggested that Tanypodinae larvae had no preferences for mite species. Because these chironomids are opportunistic organisms (
The greatest number of individuals preying on mites were observed at the Mandembe cave, which may be due to greater abundance of Tanypodinae in this cave. The greater abundance of such organisms in a single cave compared with other caves may be related to the small size of the Mandembe cave. The short allogenic stream stretch running through this cave allows higher connectivity with the epigean environment (
Although a less intense prey–predator relationship was observed between Tanypodinae and mites, such relationship has been reported for the first time in a hypogean environment in this study. Theoretical ecologists assume the importance of such weak interactions (with few occurrences in a community) due to their stabilizing effect on the trophic dynamics of systems (e.g.,
Therefore, the comprehension of possible food-web routes, including systems with omnivorous organisms, has important implications for the management and conservation of natural communities (
A General view of gut contents from a specimen of Tanypodinae (Chironomidae), where the arrow shows an specimen of Tyrophagus sp. (Acariformes: Sarcoptiformes: Acaridae) among alimentary items B Detail view of the partially digested Tyrophagus sp. C Detail of specimen already partially digested which possibly belongs to the family Frontipodopsidae (Acariformes: Trombidiformes).
We sincerely thank Gisele Pinha, who helped on Chironomidae identification. LFOB scholarships were provided by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior). TGP is also grateful to Vale S.A., which provided a postdoctoral scholarship. Funding was provided by the Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) and Conselho Nacional de Pesquisa to R.L.F. (CNPq grant nr. 304682/2014–4). Authors declare that all experiments comply with the current Brazilian laws, in which the work was performed.