shinyssd v1.0: Species Sensitivity Distributions for Ecotoxicological Risk Assessment

Living organisms have different sensitivities to toxicants. This variability can be represented by constructing a species sensitivity distribution (SSD) curve, whereby the toxicityof a substance to a group of species is described by a statistical distribution. Buildingthe SSD curve allows calculating the Hazard Concentration 5% (HC5), that is, the concentration at which 5% of the considered species are affected. The HC5 is widely used asan environmental quality criterion and a tool for ecological risk assessment (Posthuma,Suter II, & Traas, 2001).The shinyssd web application is a versatile and easy to use tool that serves to simultaneously model the SSD curve of a user-defined toxicity dataset based on four differentstatistical distribution models (log-normal, log-logistic, Weibull, Pareto). shinyssd directly calculates three estimators HC1, HC5 and HC10 associated to the four distributionmodels together with its confidence intervals, allowing the user to select the statisticaldistribution and associated HC values that best adjust the dataset.The level of confidence of the results obtained from a SSD curve will depend on the numberof species used to produce the SSD. In this sense, the first tab of the user interface is usedfor visualizing the number of species for which toxicological data are available for eachtoxicant, species group, and endpoint combination in the uploaded dataset. A minimumof species is necessary to build a SSD curve varies according to the literature (Belangeret al., 2016; Newman et al., 2000; Plant Protection Products & Residues, 2013; Wheeler,Grist, Leung, Morritt, & Crane, 2002).After selecting the toxicant and species groups, the user can filter and select subsets ofdata from the whole database by applying different quality criteria (e.g., if the studiesreported a chemical confirmation of the concentrations of the toxicant tested). The valuesentered in each column of the database serve as categories to filter the database in relationto characteristics of the bioassays. The final SSD curve is fitted to different distributionsusing the package fitdistrplus and actuar. The HC is estimated for all the distributions.By facilitating and streamlining toxicity data analysis and the creation of SSD curves, theuser interface proposed here should be useful for environmental managers and regulatorsconducting ecological risk assessments and scientific research.Fil: D'andrea, María Florencia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Body condition of Pseudis minuta Günther, 1858 (Anura: Hylidae) inhabiting an agroecosystem from south Santa Fe Province, Argentina

We present the first data on the body condition of P. minuta adults in a pond associated with an agroecosystem of the south Santa Fe Province, Argentina. Fieldwork was conducted from November 2012 to December 2013. Females and males did not differ in body condition, weight, nor length. However, males from December 2013 were in better condition than males from November 2012. Similarly, females from January 2013 were in better condition than those registered in November 2012. Our report provides for the first time an observation of the species in a landscape dominated by intensive agriculture in southern Santa Fe Province, corresponding to the Pampean region. Further studies should investigate habitat conditions and resources that allow the growth and development of this population of P. minuta in order to ensure its long-term permanence in the region.Fil: Vera Candioti, Josefina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros. Agencia de Extension Rural Venado Tuerto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: D'andrea, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

South American Cowbirds as Avian Models for Environmental Toxicity Testing

In environmental toxicity testing, the use of native species is normally recommended as it provides greater environmental realism and insures a more conservative end point for protecting ecosystems. Although pesticide products are vastly used in South American agriculture, no test protocols or guidelines exist for testing effects on native or indigenous bird species.  Instead, recommended testspecies and guidelines are essentially the ones developed for Europe and North America.  At the same time, avian pesticide regulatory assessment in South America does not require testing on passerine species although Passeriformes are normally more sensitive than other groups of birds and represent approximately 60% of all living species of bird.  The aim of this chapter is to propose South American cowbirds as candidate passerine avian models for environmental toxicity testing in South American countries.  Three species of cowbirds are widely distributed in South America and can be considered potential avian model for environmental toxicity testing: the shiny cowbird (Molothrus Bonariensis), the screaming cowbird (Molothrus rufoaxillaris) and the bay winged cowbird (Ageloides badius).  This chapters briefly reviews and compares avian environmental toxicity testing in South America and the rest of the world, and describes requirements for maintaining cowbirds in captivity and using them in toxicity testing.Fil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Poliserpi, Maria Belen. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentin

Proliferation of myogenic progenitor cells following feeding in the sub-Antarctic notothenioid fish <i>Harpagifer bispinis</i>

Feeding metabolism and the activation of myogenic progenitor cells were investigated in the fast myotomal muscle of the sub-Antarctic fish Hapagifer bispinis acclimatized to either simulated summer (10degreesC; 18h:6h light:dark) or simulated winter (5degreesC; 6h:18h light:dark) conditions. Ingestion of a single meal equivalent to 10% and 15% of body mass in simulated winter and summer groups, respectively, resulted in an average 2.6-fold and 3.6-fold increase in oxygen consumption, declining to 75% of peak values after 63 h and 46 h. In fasted individuals, the number of myogenic progenitor cells, identified by the expression of c-met, was not significantly different between simulated summer and winter fish, representing 6.6% and 5.8% of total myonuclei, respectively. However, the number of cells expressing myogenin was higher whereas the expression of MyoD was lower in winter than in summer groups. The ingestion of a single meal under winter and summer treatment regimes resulted in a significant increase in the number of cells expressing MyoD (51% and 111%) and PCNA (88% and 140%, respectively). This was followed by an increase in the abundance of c-met (74 and 85%) and myogenin (42 and 97%, respectively) positive cells, indicating the production of new myogenic progenitor cells and the commitment to differentiation of a number of them. These results show that the proliferation of myogenic progenitor cells can be induced by feeding in teleost fishes and that temperature and photoperiod influence the expression of myogenic regulatory factors.</p

New record of Pseudis minuta Günther, 1858 (Anura: Hylidae) in South Santa Fe Province, Argentina

New record of Pseudis minuta Günther, 1858 (Anura: Hylidae) in South Santa Fe Province, ArgentinaFil: Vera Candioti, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros. Agencia de Extension Rural Venado Tuerto; ArgentinaFil: D'andrea, María Florencia. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro Nacional de Investigaciones Agropecuarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Oral acute toxicity of imidacloprid, thiamethoxam and clothianidin in eared doves: a contribution for the risk assessment of neonicotinoids in birds

Neonicotinoids have recently been demonstrated to cause direct negative impacts on birds from North America and Europe. To further understand the impact of these compounds on bird species and to improve risk assessment capacities, the current study determined the acute toxicities of imidacloprid, clothianidin, and thiamethoxam formulations on South American eared doves (Zenaida auriculata). Insecticides were administered by gavage to adult doves to determine median lethal doses (LD50) according to a standardized sequential procedure. The acute toxicity of formulated imidacloprid (LD50=59mgactive ingredient, a.i./kg bodyweight, b. w.) was much higher than that of the tested formulations of clothianidin (LD50 = 4248 mg a.i./kg b.w.) and thiamethoxam (LD50 = 4366 mg a.i./kg b.w.). Imidacloprid also differed from the other two neonicotinoids in terms of the onset and intensity of intoxication signs and the times of death and recovery. All three insecticides induced a reduction in food consumption that led to body weight loss. An average weight dove of 127 g would obtain a dose equivalent to the LD50 of imidacloprid by consuming 1.7 g of treated sorghum seeds. As eared doves offered non-treated sorghum seeds 5 h per day consumed on average 6.4±1.8 g (mean±S.D.), it is concluded that these doves could feasibly be exposed to lethal doses in the field. Thiswork is the first to describe intoxication signs and report oral neonicotinoid LD50s in a wild South-American bird species.EEA ParanáFil: Addy Orduna, Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Bilológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Mateo Soria, Rafael. Instituto de Investigación en Recursos Cinegéticos; Españ

An imazethapyr-based herbicide formulation induces genotoxic, biochemical, and individual organizational effects in Leptodactylus latinasus tadpoles (Anura: Leptodactylidae)

Genotoxic, biochemical, and individual organizational effects on Leptodactylus latinasus tadpoles were evaluated after exposure to an imazethapyr (IMZT)-based commercial herbicide formulation, Pivot® H (10.59% IMZT). A determination of the value of the lethal concentration (LC50) was determined as a toxicological endpoint. Alterations in animal behavior and morphological abnormalities as well as cholinesterase (ChE), catalase (CAT), and glutathione S-transferase (GST) activities were employed as individual sublethal endpoints. Micronuclei frequencies (MNs), binucleated cells (BNs), blebbed nuclei (BLs), lobed nuclei (LBs), notched nuclei (NTs), erythroplastids (EPs), and evaluation of DNA strand breaks were employed as genotoxic endpoints. All biomarkers were evaluated after 48 and 96 h of exposure to concentrations of IMZT within 0.07?4.89 mg/L. LC50 96h values of 1.01 and 0.29 mg/L IMZT were obtained for Gosner stages 25 and 36, respectively. Irregular swimming, diamond body shape, and decreased frequency of keratodonts were detected at both sampling times. Results showed that IMZT increased GST activity and MN frequency at 48 and 96 h of exposure. Other nuclear abnormalities were also observed in the circulating erythrocytes of tadpoles, i.e., NT and BL values after 48 h, and LN, BL, and EP values after 96 h. Finally, results showed that IMZT within 0.07?0.22 mg/L increased the genetic damage index in tadpoles exposed for both exposure times (48 and 96 h). This study is the first to report the sublethal biochemical effects of IMZT in anurans and is also the first report using L. latinasus tadpoles as a bioindicator for ecotoxicological studies.Fil: Pérez Iglesias, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larramendy, Marcelo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Citología; Argentin

Oral acute toxicity of imidacloprid, thiamethoxam and clothianidin in eared doves: A contribution for the risk assessment of neonicotinoids in birds

Neonicotinoids have recently been demonstrated to cause direct negative impacts on birds from North America and Europe. To further understand the impact of these compounds on bird species and to improve risk assessment capacities, the current study determined the acute toxicities of imidacloprid, clothianidin, and thiamethoxam formulations on South American eared doves (Zenaida auriculata). Insecticides were administered by gavage to adult doves to determine median lethal doses (LD50) according to a standardized sequential procedure. The acute toxicity of formulated imidacloprid (LD50 = 59 mg active ingredient, a.i./kg body weight, b.w.) was much higher than that of the tested formulations of clothianidin (LD50 = 4248 mg a.i./kg b.w.) and thiamethoxam (LD50 = 4366 mg a.i./kg b.w.). Imidacloprid also differed from the other two neonicotinoids in terms of the onset and intensity of intoxication signs and the times of death and recovery. All three insecticides induced a reduction in food consumption that led to body weight loss. An average weight dove of 127 g would obtain a dose equivalent to the LD50 of imidacloprid by consuming 1.7 g of treated sorghum seeds. As eared doves offered non-treated sorghum seeds 5 h per day consumed on average 6.4 ± 1.8 g (mean ± S.D.), it is concluded that these doves could feasibly be exposed to lethal doses in the field. This work is the first to describe intoxication signs and report oral neonicotinoid LD50s in a wild South-American bird species.Fil: Addy Orduna, Laura. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pezzi, Juan Rafael Mateo. Consejo Superior de Investigaciones Científicas; Españ

Synergy between glyphosate- and cypermethrin-based pesticides during acute exposures in tadpoles of the common South American Toad Rhinella arenarum

The herbicide glyphosate and the insecticide cypermethrin are key pesticides of modern management in soy and corn cultures. Although these pesticides are likely to co-occur in ephemeral ponds or aquatic systems supporting amphibian wildlife, the toxicological interactions prevailing in mixtures of these two pesticides have been little studied. The current study evaluated the toxicity of equitoxic and nonequitoxic binary mixtures of glyphosate- and cypermethrin-based pesticides to tadpoles of the common South American toad, Rhinella arenarum. Two different combinations of commercial products were tested: glyphosate Glifosato Atanor + cypermethrin Xiper and glyphosate Glifoglex + cypermethrin Glextrin. When tested individually, the formulations presented the following 96 h-LC50s: Glifosato Atanor 19.4 mg ae L1 and Glifoglex 72.8 mg ae L1, Xiper 6.8 mg L1 and Glextrin 30.2 mg L1. Equitoxic and non-equitoxic mixtures were significantly synergic in both combinations of commercial products tested. The magnitude of the synergy (factor by which toxicity differed from concentration addition) was constant at around twofold for all tested proportions of the glyphosate Glifoglex + cypermethrin Glextrin mixture; whereas the magnitude of the synergy varied between 4 and 9 times in the glyphosate Glifosato Atanor + cypermethrin Xiper mixture. These results call for more research to be promptly undertaken in order to understand the mechanisms behind the synergy observed and to identify and quantify the extent of its environmental impacts.Fil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Bilológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Poliserpi, María Belen. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: D'Andrea, María Florencia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Sanchez, Marisol. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentin