Feeding by two closely related species of Chironomus (Diptera: Chironomidae) in south Baltic lagoons, with implications for competitive interactions and resource partitioning

Abstract

Four major categories of food items were determined in the gut content of chironomid larvae collected in the Curonian and Vistula Lagoons in the spring-summer period of 2009-2011. These were detritus (range from 88 to 92% of the gut content, by volume), matter of plant (2-7%) and animal origin (0.2-0.5%), and mineral particles (3-7%). Plant matter comprised pine pollen, conidia of fungi, cyanobacteria, green algae and diatoms. Matter of animal origin consisted of remnants of oligochaetes and rotifers. Food content was more diverse in the larvae inhabiting the Curonian Lagoon. The size of mineral particles in gut contents was significantly higher in C. balatonicus, although the distance between the bases of the maxillas, as a predictor of the size of the particles being eaten, was larger in C. plumosus. The gut content analysis suggested lack of clear food selectivity which potentially may lead to interspecific competition for food. However, the strength of interaction can be substantially weakened by several factors: (1) exceptionally favourable food conditions for benthic chironomids in both highly eutrophic lagoons, (2) the ability to occupy areas differing in salinity, (3) different feeding behaviour and (4) the ability to swallow particles of different size spectra.

The Comparative Gut Content Analysis of Some Chironomidae Larvae Living in the Freshwaters at Northern Thrace Region of Turkey

“…But in our study, the data included gut content data other than detritus. As a result of our gut content study, Algae was the dominant component as in other studies (Tarkowska-Kukuryk 2013;Butakka et al 2016;Kornijo´w et al 2019). According to Kornijo´w et al (2019) food of animal origin is a less involved component than plant fragment as in our study.…”

“…However, euglenoids were found only on the gut content of T. kraatzi (Figure 4). Several gut content studies reporting benthic algae as the basic food source for chironomids showed that diatoms especially constitute most of the diet (Tarkowska-Kukuryk 2013; Butakka et al 2016;Kornijo´w et al 2019). Members of the subfamily Chironominae, known as non-predatory fed primarily on algae especially diatoms, and in this study the algal diet of C. defectus, C. mancus and P. scalaenum (members of subfamily Chironominae) consisted of mostly diatoms (Figure 4).…”

“…In this study, it was compared to the gut content of C. defectus, C. mancus, P. scalaenum, and T. kraatzi collected from the freshwater ecosystems in the Northern Thrace Region of Turkey. The main food component of the alimentary tract of Chironomidae larvae is detritus (Berg 1995;Dukowska et al 1999;Kornijo´w et al 2019). But in our study, the data included gut content data other than detritus.…”

“…The gut content studies of chironomid larvae provide important insights into the modes of feeding and according to based on larval feeding modes chironomids can be grouped into collector-gatherers, collector-filterers, scrapers, shredders, engulfers, and piercers (Armitage et al 1995). But it is important to know that most chironomid larvae are not limited to a single mode of feeding and it is based on larval size, food size and quality, sediment composition (Armitage et al 1995;Kornijo´w et al 2019). The other factor on the chironomids feeding is swallowing food non-selectively and selectively in accordance with food availability, type, and size (Armatige et al 1995).…”

“…The other factor on the chironomids feeding is swallowing food non-selectively and selectively in accordance with food availability, type, and size (Armatige et al 1995). Studies of chironomid feeding show that the diet of chironomids constitutes of detritus and associated microorganisms, macrophytes, invertebrates, and especially algae (Baker and Mclachlan 1979;Armitage et al 1995;Sanseverino and Nessimian 2008;Butakka et al 2016;Öterler et al 2018;Kornijo´w et al 2019).…”