Behavioural and biochemical responses in adult Pacific white shrimp,Litopenaeus vannamei, exposed to the essential oil ofCymbopogon citratus

Abstract

This study evaluated the effects of continuous exposure to the essential oil of Cymbopogon citratus (EOC) on behavioural and biochemical parameters in shrimp Litopenaeus vannamei. Adult shrimp were randomly placed in aquaria and divided into the following groups: control (pure seawater), ethanol (360 μl L−1 of ethanol) and 5 or 10 μl L−1 EOC for 6 h. Shrimp movements were recorded using a camera for 5 min at the following timepoints: 0, 1, 2, 4 and 6 h of exposure. Light sedation and behavioural changes were observed in shrimp in the 10 μl L−1 EOC group. The total antioxidant capacity against peroxyl radicals (ACAP) in the gills and hepatopancreas of shrimp exposed to 10 µl L−1 EOC was higher than control, whereas, in the muscle, it was lower in those exposed to 5 µl L−1 EOC. In the gills and hepatopancreas, reduced glutathione (GSH) was increased in the control group. Sulphhydryl groups associated with protein (P‐SH) were decreased in the gills of shrimp exposed to 10 μl L−1 EOC. Thiobarbituric acid reactive substance levels, indicative of lipid peroxidation, were higher in the gills and hepatopancreas of shrimp exposed to ethanol, which indicates ROS formation. It is concluded that EOC reduced the swimming behaviour of L. vannamei and improved their tolerance with up to 6 h of exposure.

Methods to Induce Analgesia and Anesthesia in Crustaceans: A Supportive Decision Tool

“…Several studies have used ethanol to dissolve water-insoluble eugenol and essential oils before administering to crustaceans [ 56 , 57 , 58 , 59 , 60 , 62 , 63 ]. Separate trials were included to demonstrate that the highest-working concentration of ethanol alone did not induce anesthesia and had no observable effect compared to the control groups.…”

“…Concentrations between 0.150 and 0.500 mL·L −1 induced anesthesia within 2.5 and 1.8 min with a recovery time of between 4.2 and 6 min [ 101 ]. Lower doses between 0.005 and 0.010 mL·L −1 were also tested for long-duration anesthesia (6 h), when recovery took between 2 and 4 h, however concentrations above 0.015 mL·L −1 produced mortality in 1 h [ 58 ]. The concentration of L. alba (EOLA) recommended for anesthesia was 0.750 mL·L −1 for adults of the shrimps Penaeus pauliensis [ 101 ] and L. vannamei [ 57 ].…”

Anaesthesia of decapod crustaceans

“…tea tree) is rich in terpinen-4-ol, terpinene, cineole, and terpinolene ( Hart et al., 2000 ; Homer et al., 2000 ). The sedative and anaesthetic effects of essential oils are believed to be related to opioid and glutamate receptors, and the GABAergic system, an inhibitory neurotransmitter system ( Becker et al., 2021 ; Rial et al., 2014 ; Tsuchiya, 2017 ). Noteworthy, natural compounds should not be automatically assumed as safe because they are natural, but their use should be based on formal research.…”

“…Chlorpromazine hydrochloride causes immediate excitement followed by autotomy of appendages ( Oswald, 1977 ). Ethanol , besides being described as ineffective in most studies, can lead to agitation and disorientation ( Becker et al., 2021 ). Mint and lavender essential oils are irritant agents and shrimps exposed to them show signs of pain and discomfort; additionally, the lavender essential oil may increase shrimps’ haemolymph glucose, indicating physiological stress (Matulovic & Oshiro, 2015).…”

Optimizing Anesthetic Practices for Mud Crab: A Comparative Study of Clove Oil, MS-222, Ethanol, and Magnesium Chloride

“…Some studies have reported the anesthetic effect of MS-222 on crustaceans such as blue crabs (Callinectes sapidus), red swamp crayfish (Procambarus clarkii), and gammarids (Gammarus pulex) [8,9]. Ethanol, as an anesthetic in the neurotransmitter signaling pathway, could bind to specific receptors and promote the opening of ion channels, which leads to changes in the content of neurotransmitters, and it achieved anesthesia in crustaceans such as pacific white shrimp (Litopenaeus vannamei) and river prawn (Macrobrachium tenellum) [10][11][12]. Magnesium chloride was used in adult crayfish (Astacus astacus, and Astacus leptodactilus) and juvenile lobsters of European lobsters (Homarus gammarus) to investigate neural responses during stunning and killing [13].…”