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Lethal concentration of Cymbopogon citratus (Poaceae) essential oil for Dolops discoidalis and Argulus sp. (Crustacea: Argulidae) |
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| Authors: | Elcimara Cardoso Pereira Elzamara Castro Oliveira Elen Monique Oliveira Sousa Hugo Napoleão Pereira Silva Lincoln Lima Corrêa Rosa Helena Veras Mourão Marcos Tavares-Dias Lenise Vargas Flores Silva |
| Affiliation: | 1. Laboratory of Multiuser Chemistry, Institute of Water Science and Technology, Federal University of West of Pará, Santarém, Brazil Postgraduate Program in Continental Aquatic Resources (PPGRACAM), Santarém, Brazil;2. Laboratory of Multiuser Chemistry, Institute of Water Science and Technology, Federal University of West of Pará, Santarém, Brazil;3. Laboratory of Multiuser Chemistry, Institute of Water Science and Technology, Federal University of West of Pará, Santarém, Brazil Laboratory of Fish Physiology, Post-graduation Program in Biodiversity, Federal University of Santa Maria (UFSM), Santa Maria, Brazil;4. Instituto de Ciências e Tecnologia das Águas (ICTA), Universidade Federal do Oeste do Pará (UFOPA), Santarém, Brazil;5. Laboratory of Bioprospecting and Experimental Biology, Institute of Collective Health, Federal University of the West of Pará, Santarém, Brazil;6. Embrapa Amapá, Macapá, Brazil |
| Abstract: | This study investigated the acute toxicity (LC50-24 hr) effects of the essential oil of Cymbopogon citratus for adult Argulus sp. and Dolops discoidalis, before and during oviposition. In vitro acute toxicity (LC50-24 hr) was tested using 20, 40, 60, 80, 100, 120, 140 and 160 μg/L of C. citratus essential oil, and two control groups (one with cultivation tank water and one with cultivation tank water + alcohol) were used. Specimens of Argulus sp. and D. discoidalis submitted to acute toxicity were evaluated using histological procedures. The major chemical compounds of C. citratus essential oil were geranial (47.5%), neral (35.6%) and myrcene (6.7%). The LC50-24 hr for Argulus sp. adults was 67.97 μg/L, while for D. discoidalis it was 59.55 µg/L. In the oviposition of both species of argulids, maximum mortality began with treatments of 140 μg/L, while the LC50-24 hr for Argulus sp. and D. discoidalis was 83.98 μg/L and 82.48 μg/L, respectively. In both argulid species exposed to C. citratus essential oil, morphological alterations were observed only in the eyes, and they occurred in the ommatidium and rhabdomeres and were dependent on the concentration of C. citratus essential oil and the parasite species. |
| Keywords: | argulids crustaceans parasites phytotherapy treatment |