## 1 Introduction  
Aquaculture plays a key role in food security and nutrition for the world's population and it provides some of the main edible protein sources. It supplies the global market with diverse aquatic species raised in different production systems that suit local activity conditions. Among them, farming of the giant river prawn (_Macrobrachium rosenbergii_) has gained prominence due to its resistance to disease and high market value. In 2020, the _M. rosenbergii_ global production reached 294,000 tons, the equivalent of 2.6% of total crustacean farming [1]. Aiming at increasing productivity and economic gains and promoting animal health in crustacean farming, studies have been conducted to develop effective growth promoters and antioxidant and immunostimulant compounds. They include probiotics [2], prebiotics [3], organic acids [4], plant extracts [5; 6], and essential oils [7; 8]. From this perspective, the use of natural compounds has increased in recent years, particularly the use of essential oils (EOs). The EOs are volatile, odorous, and lipophilic substances extracted from the secretory glands of a plant, such as the leaves, flowers, roots, and seeds. They are abundant in low-molecular-weight mono- and sesquiterpenoids that provide the unique biological properties of EOs [9; 10]. The biological activities of EOs used in aquaculture include antioxidant [11; 12; 13], antiparasitic and antimicrobial [12; 13; 14], immunostimulant [15; 16], and anti-inflammatory properties [17; 18], as well as growth promotion [7; 13], anesthetic [13; 19; 20], gut health [21], and food preservative [22; 23] activities. In particular, recent studies have investigated the influence of different EOs on decapods performance. Some dietary EOs have shown no effect on animals' growth or survival, including the EOs of _Aloysia triphylla_[11] and _Lippia alba_[24; 25] in _M. rosenbergii_, and a blend of organic acids (citric acid and sorbic acid) and EOs (thymol and vanillin) in _Penaeus vannamei_[26]. Meanwhile, _Cuminum cyninum_ (5 and 10 g kg feed\({}^{-1}\)) improved the performance of _Penaeus vannamei_[27]. The plant _Cuminum gratissimumum_, commonly known as clove basil or African basil, is a tropical perennial aromatic plant in the Lamiaceae family, and it is found in Africa, Asia, and South America [28; 29]. Its use encompasses herbal medicine (inc. described properties as an anxiolytic, antimicrobial, anti-diabetic, anti-hypertensive, and antinociceptive agent) and food condition [30]. The EO of _O. gratissimum_ (EO-OG) is mostly obtained by steam distillation of the infloresence and leaves. In the aquaculture context, the use of EO-OG has demonstrated multiple benefits. Its use as a sedative, anesthetic, antimicrobial, antiparasitic, and immunostimulant in fish is well known [31; 32; 33; 34]. In decapods, the use of EO-OG is mostly associated with its sedative and anesthetic properties [20; 35; 36]. Different chemotypes of EO-OG have been described, including citral, ethyl cinnamate, eugenol, linalool, and thymol [37]. In Brazil, the eugenol EO-OG chemotype is the common one found and the biological activities of this EO are attributed to its major constituent (i.e., eugenol). The antioxidant defense system is a conserved biochemical defense mechanism in vertebrates and invertebrates. Excess reactive oxygen species (ROS) cause an imbalance in the antioxidant system, causing so-called oxidative stress [38]. The antioxidant system minimizes the negative oxidizing effects of ROS through antioxidant enzymes such as catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione-S-transferase (GST; a detoxification enzyme from metabolism phase II), as well as non-enzymatic antioxidants, including reduced glutathione (GSH). Essential oils have antioxidant activity, and their dietary use has been beneficial to farmed shrimp [11; 24].