Short-Term Feeding with Hesperozygis ringens Essential Oil Modulates Transportation-Induced Physiological Responses in Colossoma macropomum

Hesperozygis ringens essential oil (HREO), rich in pulegone and limonene, has potential application in aquaculture due to its beneficial properties. This study evaluated the effects of dietary supplementation with HREO (0.0, 0.75, 1.0, and 2.0 g HREO kg feed−1) for 30 days on the physiological responses of Colossoma macropomum before and after a simulated 4 h transport. Fish were sampled at four time points: before transport (Basal), immediately after transport (IAT), and at 24 h (AT24) and 48 h (AT48) post-transport. Growth performance and survival (>96%) were not affected by HREO. Hemoglobin concentration, mean corpuscular hemoglobin concentration (MCHC), and intestinal coefficient showed significant responses to dietary HREO. After transport, survival was 100% for all treatments, and hematological and biochemical parameters varied according to dose and recovery time, with 2.0 g HREO kg feed−1 showing the most consistent benefits, such as stabilization of hemoglobin, MCHC, and plasma proteins during recovery at AT24 and AT48. Water quality parameters did not differ between treatments at transportation end. These findings suggest that dietary HREO may contribute to enhance the physiological responses to transport in C. macropomum, supporting its potential use as a sustainable nutritional strategy.