Malathion acute toxicity in tadpoles of Duttaphrynus melanostictus, morphological and behavioural study

Abstract

The present study was undertaken to evaluate the median lethal concentration (LC 50 ), morphological deformities and changes in behavioural responses caused by commercial formulations of malathion on Duttaphrynus melanostictus tadpoles. The LC 50 value was found to be 7.5 mg/l and ability of malathion to cause morphological anomalies and changes in behavioural responses in tadpoles were studied at sublethal concentrations of 0.5 mg/l (1/15th), 0.75 mg/l (1/10th) and 1.5 mg/l (1/5th) for a duration of 5 days. The morphological defects and changes in behavioural responses like notochord curvature and loss of fright response respectively were witnessed as an important conduct; in addition, other symptoms under both the parameters were known to be time (i.e. developmental stage) and concentration dependent thereby acknowledging the direct cause of damage due to malathion. Thus, based on the present study, care must be taken when this chemical is in use at agricultural sites especially nearby aquatic ecosystems. ª 2015 The Egyptian German Society for Zoology. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Biochemical Modulations in Duttaphrynus melanostictus Tadpoles, Following Exposure to Commercial Formulations of Cypermethrin: An Overlooked Impact of Extensive Cypermethrin use

“…The overall study suggests the devastating tendency of cypermethrin against D.melanostictus tadpoles by altering its biochemical make up that consisted of antioxidant enzyme status along with protein and free amino acid levels. Even though pesticides and similar toxic chemicals have been reported for causing adverse effects on fishes [45,46,47,48,49], their role in declining trend of amphibian population is of highest concern [50], the need for stricter laws in controlling indiscriminate use of highly toxic pesticides still awaits its initiation.…”

“…This was followed in order to avoid excessive animal kill. 1/3 rd (1.11 µg/L) of the previously determined 96 h LC 50 (3.34 µg/L) [12] was selected as sublethal concentration for the present investigation. Durations of 1, 2, 3 and 4days of exposure were carried out under standard semistatic renewal assay tests.…”

“…Annual global use of agricultural sprays is estimated to be 11.2 billion kg [2]. With this range of indiscriminate pesticide use, has resulted in inevitable consequence of compromised health status of aquatic fauna with partial contribution to drastic decline in amphibian population as well [3,4]. According to the first global assessment of the status of amphibian species, more than 40% of the world's 5743 amphibian species have experienced recent declines, a situation far worse than that reported for mammals or birds [5].…”

Performance studies on jumping behaviour in froglets exposed to commercial grade malathion

“…into froglets. RESULT -Jumping performance at low concentrations was comparable to control group but at high concentration it increased -Reason to be investigaged Penn, 2004; Krishnamurthy and Smith, 2010) and disrupt endocrine activity (Lal et al, 2013;David and Kartheek, 2015), we anticipated that chronic exposure to malathion at larval stage of these tadpoles can also affect the performance of locomotion in froglets. Therefore, the tadpoles of Fejervarya limnocharis were exposed to sub-lethal concentrations of commercial grade malathion to investigate their jump performance post metamorphosis.…”

Os riscos ambientais no Brasil devido ao uso do defensivo Malathion Emulsão Aquosa - EA 44% no controle de Aedes Aegypti (Linnaeus, 1762) (díptera; culicidae): uma revisão

“…Estudos demonstram que o Malathion em grau comercial (50% CE) tem uma concentração letal média de 7,5 mg/l para os girinos da espécie Duttaphrynus melanostictus e que mesmo em doses menores pode causar grave ameaça para o animal, já que as características morfológicas e comportamentais são afetadas, sendo assim um indicativo de como o Malathion afeta o ecossistema prejudicando a conservação do habitat aquático (DAVID et al, 2015).…”