Abstract
<title>Abstract</title> <p> Embryonic development in cephalopods is a critical phase characterized by high energy demands, high metabolic production of reactive oxygen species (ROS) and limited aerobic flexibility. As postulated in <italic>Octopus maya</italic> , maternal heat stress transfers ROS and oxidative damage to offspring, potentially compromising their ability to cope with ocean warming scenarios. The present study evaluated whether embryos and early juveniles from females subjected to heat stress (30°C) regulate their respiratory metabolism, activate antioxidant mechanisms, and modulate oxidative balance throughout development. Routine, maximum and standard metabolic rates, aerobic capacity, antioxidant enzyme activity, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST), oxidative damage (lipid peroxidation and protein oxidation), total glutathione levels, and esterase activity were measured in embryos and juveniles maintained at 24, 26, and 30°C. Embryos were found receiving a high ROS load, which in addition were produced by the embryos during development. This double ROS load caused deformities and high embryonic mortality, associated with the inability of this life cycle phase to neutralize the oxidative damage produced by ROS. In the juvenile stage, animals maintained at 24°C showed metabolic and morphological recovery, while those incubated at 30°C showed smaller body size, accelerated yolk depletion, and antioxidant system disruption. Intermediate values were observed in juveniles maintained at 26°C. The results suggest that maternal heat stress profoundly affects the embryonic stage of <italic>O. maya</italic> . However, juveniles hatching in a suitable thermal environment (24°C) showed physiological mechanisms to neutralize the negative maternal stress effects, suggesting that populations may persist under these conditions. </p>