Ivana Živić

Chironomid faunal composition represented by taxonomic distinctness index reveals environmental change in a lotic system over three decades

The widely distributed family of the Chironomidae represents the most diverse and abundant group of macroinvertebrate fauna and potentially provides information on stream water quality and the effect of anthropogenic disturbances. Change in the chironomid faunal composition in the Southern Morava River basin (Serbia) was examined by comparing data from 1981 and 2010. We tested the performance of the parameter “taxonomic distinctness” (delta+) as an indicator of water quality and examined the possible relationship between delta+ and water quality using PCA. The 2010 survey yielded 96 taxa in 28 localities over three seasons. In total, 10,179 specimens represented the five subfamilies. Chironomid diversity was captured with the index delta+ that is based upon taxonomic distinctiveness and purported to be independent of sampling effort. Delta+ was correlated to total species richness and is significantly higher now than it was in 1981. In keeping with PCA results, delta+ was increasing in accordance with water quality increase. We conclude that delta+ is a useful measure for estimating anthropogenic disturbance over time. The linear relationship between delta+ and the water quality gradient gives rise to a novel metric, independent of sampling effort, in the multimetric approaches of analyzing macroinvertebrate assemblage data for bioassessments.

Influence of the temperature regime on the composition of the macrozoobenthos community in a thermal brook in Serbia

In contrast to cold and eurythermal waters, benthic communities of warm brooks in temperate regions have been inadequately studied. In order to investigate the effects of water thermal regime on the benthic communities of warm waters and their relationships with those of cold and eurythermic ones, the macrozoobenthos was studied at eight sites in the Toplica River, and at four sites in its tributary, the Termalni brook. Investigations were carried out seasonally from April 2000 to January 2001. Warm waters of the Termalni brook were characterized by specific macrozoobenthos assemblages that exhibited significant differences to the populations of eurythermal and cold waters of the Toplica River. The dominant taxa in the macrozoobenthos community of warm waters were mainly Gastropoda species. Moreover, benthic communities of warm waters were characterized by lower diversity and greater biomass in comparison with those of cold and eurythermal waters. The gradient of average annual temperatures represented the main ecological factor influencing changes of diversity and biomass along the course of the investigated Termalni brook. Inflow of warm waters at site T6 lead to a decrease in macrozoobenthos abundance and changes in qualitative and quantitative composition of the benthocoenosis of a highland stream, but did not significantly alter diversity.

Evaluation of oxidative stress biomarkers in the freshwater gammarid Gammarus dulensis exposed to trout farm outputs

The current study reports a combined seasonal monitoring of the Crnica River watercourse using physico-chemical parameters and biomarkers measured in Gammarus dulensis with the aim of correlating the effects of pollution with the level of oxidative stress biomarkers in this amphipod. The pollution source is identified as a trout farm in the upper part of the Crnica River (Eastern Serbia). Physico-chemical water parameters and sediment trace element concentrations were measured in the Crnica River during three seasons. Three localities downstream [CR2, CR3, and CR4 (20 m, 400 m, and 1.3 km from the trout farm discharge, respectively)] were assessed in comparison with a reference location (CR1), 250 m upstream from the trout aquaculture in the Crnica River. Antioxidant biomarkers including the enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione-S-transferase (GST) were determined in pooled samples of G. dulensis. Our findings showed statistically different antioxidant enzyme levels in gammarids from the first downstream locality (CR2) compared to those from other three localities. The results indicate that oxidative stress occurred to some extent despite the assumed antioxidant induction as a result of exposure to elevated levels of some elements and changed water parameters, the effects seeming in part to be mediated by suppression of SOD and CAT (during summer and autumn); and by suppression of GPX and GR (during autumn) at the CR2 locality. The activity of GST in all seasons was higher at the CR2 locality than at the other localities, suggesting the presence of some permanent xenobiotic next to the aquaculture output. Seasonal difference in the physical and chemical water parameters and sediment trace element concentrations were observed. Overall, our results indicate a locality- and season-dependent antioxidant enzymes response in G. dulensis, pointing at progressively reduced deleterious effect of trout farm outputs with movement further downstream.

Morphological features of larvae of Drusus plicatus Radovanović (Insecta, Trichoptera) from the Republic of Macedonia with molecular, ecological, ethological, and distributional notes.

Abstract A description of the larva of Drusus plicatus Radovanović is given for the first time. The most important diagnostic characters enabling separation from larvae of the other Drusinae from the southeast Europe are listed. Molecular, ecological, and ethological features and distribution patterns of the species are given. Additionally, information on the sympatric caddisfly species of the three springs where larvae and adults of Drusus plicatus were found and presented.

Benthic diatoms of the Vrla River (Serbia) and their application in the water ecological status assessment

Abstract Epilithic diatoms from the Vrla River (Serbia) have been used to assess the ecological status of water. A total of 227 diatom taxa belonging to 50 genera were identified in the Vrla River during six research seasons with 13 dominant species recorded. Gomphonema (30 species), Navicula (28) and Nitzschia (26) were the most species-rich genera, followed by Pinnularia (12) and Encyonema (11). One taxa was recorded as new to Serbia – Geissleria acceptata. CCA grouped the diatom taxa into three main groups. The first group included taxa found at most of the sampling sites, the second group involved diatom taxa significantly positively correlated with the oxygen, while the third group showed positive correlation with temperature. RDA showed that some diatom taxa, including: Cocconeis placentula var. placentula, C. placentula var. lineata, C. pseudolineata and Mayamaea atomus var. permitis, are significantly positively correlated with temperature, while others, for example Achnanthidium minutissimum, Hannaea arcus, Nitzschia pura are mostly correlated with total phosphorus, alkalinity and water hardness. The ecological status of the Vrla River ranged from moderate, good to high. It was shown that according to the diatom indices, the ecological status of water downstream and upstream of a trout fish pond was slightly different.

Effect of supplemental feeds on liver and intestine of common carp (Cyprinus carpio) in semi-intensive rearing system: histological implications

Abstract In order to determine effects of different types of supplementary feed on the histology of liver and intestine of carp reared in a semi-intensive system, a six-month field experiment was carried out. Carp yearlings were fed different supplemental feeds: cereals (CF), pelleted (PF) and extruded (EF) compound feeds. Hepatocytes histomorphometry revealed larger nuclear profile area of EF-fed fish compared to other two groups, while cytoplasmic profile area of the hepatocytes decreased in following sequence: CF > EF > PF. Lower nucleus/cytoplasm ratio was found in CF-fed fish compared to EF-and PF-fed fish. Striking, season dependant finding, was that regardless of the type of supplementary feed the number of lipid droplets in hepatocytes was highest in July and August, lipid depletion occurred in September and October, while glycogen was present in hepatocytes throughout the study. No size difference between groups was observed for enterocytes height, absorptive surface height and number of goblet cells in tunica mucosa, but a strong relationship between length of intestinal folds and fish weight was found. Histological analysis revealed a difference among three types of supplemental feed used in this field study: extruded or steam-pelleted feed induced better nutritional status of common carp in comparison to cereals. At the same time, histomorphometry indicated some differences between EF-and PF-fed fish.

Ithytrichia Eaton, 1873 (Hydroptilidae: Trichoptera): A Genus New for the Entomofauna of Serbia

ABSTRACT: During field work carried out in 2003, 2004, 2007, and 2011, larvae of the genus Ithytrichia (Trichoptera, Hydroptilidae) were identified as part of a benthic macroinvertebrate survey. Specimens of Ithytrichia lamellaris Eaton, 1873 were collected from independent localities in four rivers of Eastern and Central Serbia, namely the Black Timok, Mlava, Morava, and Western Morava. For the fauna of Serbia, three species within the family Hydroptililae were known up to now: Hydroptila vectis, Hydroptila sparsa, and Agraylea multipunctata. This is the first record of Ithytrichia larvae in watercourses of Serbia (Danube basin). Analysis of the environmental data indicates that I. lamellaris is a typical eurythermic species which inhabits slightly alkaline waters rich in dissolved oxygen, with a moderate organic load and abundant aquatic vegetation.

Uncertainty of using habitat fidelity in biomonitoring based on benthic diatoms - the Raška River case study

Epilithic diatoms are frequently recommended for river biomonitoring, while much less emphasis is placed on epiphytic communities. This study considers use of epiphytic and epilithic diatom communities from the Raška River in biomonitoring. A total of 212 diatom taxa were recorded in both communities. Dominant diatoms were Achnanthidium minutissimum (Kützing) Czarnecki, A. affine (Grunow) Czarnecki, A. subatomus (Hustedt) Lange-Bertalot, Amphora pediculus (Kützing) Grunow, Diatoma vulgaris Bory, Gomphonema tergestinum (Grunow) Fricke, Cocconeis placentula var. lineata (Ehrenberg) Van Heurck, Melosira varians Agardh and Navicula tripunctata (Müller) Bory. Redundancy analysis (RDA) was used to detect the relationships between diatoms, some environmental factors and sampling sites. Diatoms of the epiphytic community showed a clearly grouping in relation to the sampling sites as compared with diatoms of the epilithic community. Species common to both communities showed a similar correlation with some environmental variables (BOD, pH, NH4+, TP, NO3− and conductivity), with three exceptions (Diatoma vulgaris, Cymbella compacta, and Encyonema silesiacum). Pearson’s correlation coefficient showed correlation between selected environmental variables and diatom indices calculated using OMNIDIA 6.2 software (TDI, IPS, CEE, GENRE, TID, SID, SHE and IDSE/5). Diatoms of the epiphytic community are more clearly clustered in relation to the sampling sites as compared with diatoms of the epilithic community. According to our results there is still “place” in biomonitoring for epiphytic community. The present study highlights the necessity of sampling both epiphytic and epilithic communities because substrate specificity could play important role in biomonitoring.

The larvae of the European Helicopsyche species (Trichoptera: Helicopsychidae)

This synoptic paper gives descriptions of the hitherto unknown or poorly known larvae of Helicopsyche megalochari Malicky 1974 and H. revelieri McLachlan 1884 (Trichoptera: Helicopsychidae). We present information on the morphology of the larvae and illustrate the most important diagnostic features. This information is used for the construction of a comprehensive larval key to the five European species of family Helicopsychidae. In the context of this key, larvae can be easily diagnosed by setation patterns of the dorsal head capsule, submentum shape, and propleuron morphology. With respect to distribution, Helicopsyche megalochari has been reported from the Greek Islands of Andros, Euboea, Ikaria, and Naxos whereas H. revelieri is known from the islands of Capraia, Corsica, and Sardinia. In addition, ecological characteristics and distributions of the European species are briefly discussed.

The trout farm effect on Dinocras megacephala (Plecoptera: Perlidae) larvae: Antioxidative defense

Trout production represents a major agricultural activity in Serbia. Organic compounds are drained into the environment, usually without previous sedimentation, thus affecting the stream biota. Considering that biological monitoring is commonly based on aquatic macroinvertebrates as target organisms, the authors used larvae of Dinocras megacephala to estimate trout farm effects on the mass of the larvae and their antioxidative defense in pollution stress conditions. Four locations were chosen along the channel of the Raška River, 2 upstream (L1, L2) and 2 downstream (L3, L4) from the trout farm outlet. Basic physical and chemical water parameters were measured. Superoxide dismutase (SOD) and catalase (CAT) activity changes were analyzed to determine the level of oxidative stress caused by the increase of organic compounds originating from the trout farm. Dissolved oxygen concentration decreased from the upstream to downstream locations. Furthermore, the concentration of ionized ammonia was almost 10 times higher at the downstream locations than at the upstream locations. Larval mass, as well as CAT activity, was significantly higher at L3 compared with the other 3 locations. Activity of SOD was significantly higher at L3 than at L1. The results indicate that higher concentrations of organic compounds from the trout farm induce clear changes in the status of the antioxidant defense of D. megacephala larvae. Environ Toxicol Chem 2016;35:1775-1782.