Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

Holem, Ryan R.; Hopkins, William A.; Talent, Larry G.

doi:10.1016/j.envpol.2007.05.017

Cited by 29 publications

(12 citation statements)

References 35 publications

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“…Past attention was focused on measuring body burdens of various pollutants to wild reptiles which gave an understanding of historical exposure of given populations (Buono et al, 2007;Holem et al, 2008;Mann et al, 2007;Moss et al, 2009;Trinchella et al, 2006;De Falco et al, 2007;Keller et al, 2006;Simoniello et al, 2010;van de Merwe et al, 2010). However, the population-level effects and actual risks of pollutants on reptiles are still generally understudied (Weir et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Stereoselective metabolism, distribution, and bioaccumulation brof triadimefon and triadimenol in lizards

Wang

et al. 2014

Ecotoxicology and Environmental Safety

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a b s t r a c tIn this research, Chinese lizards (Eremias argus) were chosen as laboratory animal to evaluate the stereoselectivity in the processes of metabolism, distribution, and bioaccumulation of triadimefon. A validated chiral high-performance liquid chromatography coupled with triple quadruple mass spectrometry (HPLC-MS/MS) method was developed for determining enantiomers' residues of parent compound triadimefon and its metabolite triadimenol in lizard blood and tissues. Pharmacokinetic results of single-does exposure suggested that S-(þ )-triadimefon was metabolized easier than R-( À )-triadimefon, and RR-(þ )-triadimenol was the main metabolic product of triadimefon. During the continuous exposure of two dose (40 mg/kg bw Á d and 200 mg/kg bw Á d), enantiomers of triadimefon and triadimenol were detected in all body compartments, with the highest triadimefon concentrations in brain. However, the triadimenol concentrations were not significantly different among the compartments. The concentrations of RS-( þ)-triadimenol were negative correlated with concentrations of RR-(þ )-triadimenol both in blood (r¼ À0.775, p¼0.024) and liver (r¼ À0.834, p¼0.02) in 200 mg/kg bw Á d group, which indicates that chiral conversion between enantiomers of triadimenol might exist in the metabolic process of triadimefon. In all the processes, the enantiomer fractions (EFs) of R-(À )-triadimefon and RR-(þ )-triadimenol were significantly different from their natural ratios, 0.5 and 0.1, respectively, which proved that metabolism, bioaccumulation, and distribution of triadimefon and triadimenol in lizards were enantioselective. These results help enrich and supplement the knowledge of the stereoselective behaviour of triadimefon and triadimenol in reptile.

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Section: Introductionmentioning

confidence: 99%

Stereoselective metabolism, distribution, and bioaccumulation brof triadimefon and triadimenol in lizards

Wang

et al. 2014

Ecotoxicology and Environmental Safety

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“…For example, the S. invicta sting mechanism may permit injection of venom, but not allow venom to penetrate the deeper layers of muscle necessary to impede muscle contraction (Yeh et al,'75), or the lethal consequences of envenomation may not be linked to impaired motor function at all. Other performance metrics may be more sensitive than maximal sprint speed and capture subtler effects: arboreal performance may better test fine motor control (Holem et al, 2008), and endurance, an aerobic test, may better reflect the damage caused by lysis of red blood cells (Bennett,'78).…”

Section: Discussionmentioning

confidence: 99%

Sublethal effects of invasive fire ant venom on a native lizard

Boronow

Langkilde

2009

J. Exp. Zool.

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Invasive species can impose novel selection pressures on natives, such as toxins to which native taxa are not adapted. Native species may survive such invasions by evolving mechanisms to avoid toxin exposure or increase toxin tolerance. Red imported fire ants (Solenopsis invicta) employ an alkaloid-based venom to defend their colonies and capture prey. In this study we aim to characterize the sublethal effects of invasive fire ant venom on a native vertebrate, the eastern fence lizard (Sceloporus undulatus), and to determine whether lizard populations that have been exposed to these fire ants for approximately 35 generations have increased physiological resistance to the venom. We documented the sublethal impact of fire ant venom on fence lizard performance by naturally exposing lizards to fire ant stings and recording changes in three fitness-relevant measures: bite force, righting ability, and sprint speed. We also measured blood hemolysis induced by the venom. To test for the development of physiological resistance to fire ant venom we compared whole-body performance and hemolysis for two populations of lizards with different fire ant invasion histories. Fire ant venom showed no dosage-dependent sublethal effects on performance. In addition, there is no evidence that lizards have evolved increased physiological resistance: the impact of fire ant venom on whole-body performance and hemolysis did not differ between the naïve and experienced populations. Lizards may instead rely on adaptive shifts in escape behavior and morphology following invasion to survive fire ant attack.

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“…Compared to measurements for other OPs made in previous studies in reptiles [23,24], the malathion concentrations that we observed appear low in the monitors from Niamey and occasionally important in some specimens from Diffa. However, it is noteworthy that the toxicity of malathion may be particularly high in squamates, as evidenced by experimental studies [26,27] showing that small doses of this compound can provoke physiological and behavioral disorders. The actual consequences of the malathion levels that we observed in Sahelian Africa thus remain undetermined.…”

Section: Site Contaminationmentioning

confidence: 99%

Assessing environmental contamination around obsolete pesticide stockpiles in West Africa: Using the Nile monitor (Varanus niloticus) as a sentinel species

Ciliberti

Berny

Vey

et al. 2011

Enviro Toxic and Chemistry

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Environmental contamination caused by obsolete pesticide stocks was assessed using the Nile monitor (Varanus niloticus) as a sentinel species. Organochlorines and organophosphates were quantified by gas chromatography in abdominal fat and the liver, respectively. Results were compared to those obtained from three other sites, characterized by different histories of contamination. None of the previously stocked pesticides were recovered. Low to moderate levels of 4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) were quantified in monitors from all sites. Malathion and 4,4'-dichlorodiphenyldichloroethane (4,4'-DDD) also were detected sporadically. Interindividual variability was substantial. Correlations between pesticide loads and individual characteristics were considered. The nondetection of previously stocked pesticides in the monitors' tissues, their contamination by other pesticides, and the value of V. niloticus as a monitoring tool for environmental contamination are discussed. The results indicate a situation of low concern and draw attention to the importance of local conditions in determining environmental dangers associated with potential pollution sources.

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Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

Cited by 29 publications

References 35 publications

Stereoselective metabolism, distribution, and bioaccumulation brof triadimefon and triadimenol in lizards

Stereoselective metabolism, distribution, and bioaccumulation brof triadimefon and triadimenol in lizards

Sublethal effects of invasive fire ant venom on a native lizard

Assessing environmental contamination around obsolete pesticide stockpiles in West Africa: Using the Nile monitor (Varanus niloticus) as a sentinel species

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