ABSTRACT
A wide range of pharmaceuticals and endocrine disrupting compounds enter freshwaters globally. As these contaminants are transported through aquatic food webs, understanding their impacts on both aquatic and terrestrial ecosystems remains a major challenge. Here, we provide the first direct evidence of the transfer of pharmaceuticals and endocrine disruptors through the aquatic-terrestrial habitat linkage by emerging aquatic insects. We also show that the type of insect metamorphosis and feeding behavior determine the bioaccumulation patterns of these contaminants. Adult Trichoptera, an important food source for riparian predators, showed an increased body burden of pharmaceuticals and endocrine disruptors. This implies that terrestrial predators, such as spiders, birds, and bats, are exposed to mixtures of pharmaceuticals and endocrine disruptors of aquatic origin, which may impact their physiology and population dynamics. Overall, our study provides valuable insights into the bioaccumulation patterns and trophic cross-ecosystem transfer of these contaminants, from aquatic primary producers to terrestrial predators.
Subject(s)
Endocrine Disruptors , Pharmaceutical Preparations , Animals , Ecosystem , Food Chain , InsectaABSTRACT
Two new aquatic oligochaete species are described from tufa barriers in Croatia. The reproductive system in the phallodriline Aberrantidrius mihaljevici Vuckovic et al. n. sp. conforms to the general pattern in the genus but it is distinguished by a combination of characters, including the shape and length of penial chaetae (3 times the mean length of somatic chaetae), atrium shape and spermathecal pore position (anterior in the postatrial segment). The lumbriculid Stylodrilus tofaceus Rodriguez et al. n. sp. is mainly distinguished from congeners by the spindle-shaped spermathecal ducts with high lining epithelium, and position of the spermathecal pores. These two new taxa reveal that aquatic oligochaete communities in tufa barriers of karstic regions may be of particular interest with respect to diversity of endemic taxa, and also for study of colonization routes of this interesting habitat, with possible relations with groundwaters. The finding of one specimen attributable to the genus Eclipidrilus may open ainteresting research on the biogeography of this Nearctic genus.
Subject(s)
Annelida , Oligochaeta , Animals , Croatia , Ecosystem , Genitalia , Groundwater , MaleABSTRACT
Predation is a biotic interaction that links water mites to different taxonomic groups of benthic invertebrates. Diptera larvae (Chironomidae) and microcrustaceans (Cladocera, Copepoda, Ostracoda) are known to be the most commonly preferred prey by water mites. Although these predatory interactions are known from observations and ex situ investigations, the distribution patterns and co-occurrence of water mites and their prey in littoral lentic habitats have been poorly studied. Our goal was to determine whether predation might serve as a significant factor in water mite assemblage composition and distribution. Samples were taken from littoral zones of 21 artificial lakes (reservoirs) in the Dinaric Western Balkan ecoregion of Croatia. At every site, 10 samples were collected with regard to shore slope in depth zones of up to 1 m. In total 490 samples were collected from April 2016 to July 2017. Data analysis showed that the spatial distribution of water mites was partially correlated with the environmental parameters we measured (explaining 45.1% of total water mite variation). A positive correlation between water mite abundance and diversity and depth gradient (favouring more stable conditions in deeper parts of the littoral zone) was also observed. Finally, water mite abundance and species richness variation were found to be best predicted by the abundance of potential prey groups. Predation was statistically determined to be a strong dispersion variable, most probably influencing both spatial distribution and composition of water mite assemblages.
