Observations of wild male O. maya suggest that temperatures below 27 degrees C favour their reproductive performance. From these observations we hypothesize that, as in females, the temperature modulates the reproductive performance of adult O. maya males. The study aimed to evaluate the physiological condition, reproductive success, and histological damage in testis of male O. maya exposed to thermal stress, to determine the implications of ocean warming over their reproductive performance. High temperatures (28-30 degrees C) negatively affect the growth and health of male O. maya. In octopuses maintained at 30 degrees C, as a consequence of the thermal stress we observed an increment in the haemocytes number, a reduction in the oxygen consumption rate, and an inflammatory process in the testis. The number of spermatozoa per spermatophore was not affected by temperature, but higher spermatophores production was observed at 30 degrees C. The paternity analysis showed that the offspring had multiple paternity with an average of 10 males contributing in a single spawn. The paternal contribution was affected by temperature with high, medium, or no paternal contribution in animals maintained at 24 degrees C (control group), 28 degrees C and 30 degrees C, respectively. The temperatures from 28 degrees C to 30 degrees C deeply affected the reproductive performance of Octopus maya males, suggesting that, as embryos, reproductive performance of adult males of this octopus species can be used as a tool for monitoring thermal changes in Yucatan Peninsula, located at the entrance of Gulf of Mexico.