Introduction
Studies have shown that light intensity and color can induce stress in the shrimp Penaeus vannamei, as evidenced by behavioral responses such as tail flips, looping movements and thigmotaxis. The findings suggest that orange light wavelength (600nm) is preferred by the shrimp and does not trigger stress compared to other light conditions (Pichon et al., 2025). However, these results are primarily behavioral. This raises the question of how such light conditions affect the shrimp from a physiological perspective. In particular, this can be investigated using physiological stress markers such as respirometry and blood glucose levels.
Material and Methods
For each respirometry trial, we test groups of four shrimp. Each shrimp is placed in its own metabolic chamber, where oxygen levels are continuously recorded by a data acquisition system. The shrimp are successively exposed to five different light colors (white, orange, blue, green, yellow) for a defined period of time. Each experiment is repeated five times. Light treatments order has been randomized to minimize potential bias. Before starting respirometry trial, shrimp are acclimated during 5 days under darkness within a recirculating aquaculture system (RAS).
Between successive respirometry runs, aeration is restored for 5 minutes to reoxygenate the system, during which the light is turned off. At the end of this period, the aeration is turned off for 15 minutes, with the next light condition initiated simultaneously. Except during these successive illuminated periods of 15 minutes, the experiment is conducted in darkness.
For the experiment measuring hemolymph glucose levels, shrimp are maintained in a separate recirculating aquaculture system (RAS). Each tank, containing 15 shrimp, is exposed to a specific light condition for one day. At each time point (T+15 min, T+30 min, T+2 h, T+4 h, and T+6 h), three shrimp are sampled for hemolymph collection and subsequent glucose analysis. The glucose results obtained will be compared to those obtained from Apriyadi et al., 2023.
Results and Discussion
Based on behavioral results reported by Pichon et al., 2025, an increase in oxygen consumption is expected under white, yellow, and green light conditions, whereas a decrease is anticipated under orange light conditions. Similarly, regarding hemolymph glucose levels, findings from Apriyadi et al., 2023, suggest higher glucose concentrations under white, yellow, and green light, with a reduction under orange light conditions. However, it will be particularly informative to examine how these responses evolve over time, especially in relation to potential habituation effects.
References
Apriyadi, A.F., Mahasri, G., Sulmartiwi, L., 2023. Stress level of vaname shrimp (Litopenaeus Vannamei) with infested ciliata pathogens after open wet transportation. IOP Conf. Ser. Earth Environ. Sci. 1273, 012003. https://doi.org/10.1088/1755-1315/1273/1/012003
Pichon, C., Kersante, P., Le Reste, G., Darmaillacq, A.-S., Jozet-Alves, C., 2025. Effects of light colour and intensity on stress responses in the Pacific white shrimp (Penaeus vannamei). Appl. Anim. Behav. Sci. 289, 106694. https://doi.org/10.1016/j.applanim.2025.106694