Effects of temperature on the life cycle of Neobenedenia sp. (Monogenea: Capsalidae) from Seriola rivoliana (Almaco jack) in Bahía de La Paz, BCS Mexico.

Seriola rivoliana cultivated in Mexico are infected by Neobenedenia sp. (Monogenea: Capsalidae), resulting in dermal ulceration and subsequent bacterial invasion that can cause fish death. This study assesses the effects of temperature over hatching success, oncomiracidia longevity, and infection success. The experimental design consisted of culturing the parasite at temperatures ranging between 16 and 32 °C. The oncomiracidia infection success, time to sexual maturity, and size at sexual maturity of Neobenedenia sp. were examined only at three temperatures (20 °C, 24 °C, and 30 °C). Experiments were conducted under controlled conditions in the laboratory. The oncomiracidia development was found to be faster at warmer temperatures (4-5 days between 24 and 30 °C) than in colder treatments (7-11 days between 18 and 20 °C). Hatching success and oncomiracidia longevity were higher at 24 °C and 26 °C. At 20 °C, 24 °C, and 30 °C, infection success was greater than 90%. Additionally, the laid eggs were observed at 9, 12, and 15 days at 30 °C, 24 °C, and 30 °C, respectively. The results of this study will allow for improving the temporal schedule of applications of treatments against Neobenedenia sp. by the function of temperatures. In conclusion, it is recommended to treat fish more frequently if the temperature in cultures is higher than 24 °C, because Neobenedenia sp. development is faster. As an alternative, the fish could be moved to deeper and cooler waters.