Background:

Penaeus vannamei suffers a number of high-mortality diseases that cause enormous economic losses.

Aim.

To stimulate the immune system of Penaeus vannamei shrimps following non-lethal heat stress (NLHS).

Materials and methods:

Two NLHS conditions (acute and chronic NLHS) were developed. The acute challenge lasted 30 minutes, along which samples are collected at different intervals (0,30min, 3, 6, and 12 h). The chronic challenge lasted 5 minutes and took seven days. The samples were collected (0 and 7d) to evaluate the immunological response and osmotic stress resistance. The shrimp at 28 °C made the control group.

Results:

An acute challenge ANOVA showed that NLHS in culturing conditions P. vannamei was 37°C. The ANOVA (double) and HSD Tukey detected an increase (P<0.05) in enzyme phenoloxidase at 6 and 12 h after NLHS (0.04593 and 0.05268 x 10-1 mg), when compared with 30 min and the control (0.0003037 and 0.001217 x 10-1 mg). The chronic NLHS showed high phenoloxidase stimulation (P<0.05) at 7 days (4.233 ±10-1mg). Meanwhile, the control showed 1.392 ±10-1mg. Survival against osmotic stress at 0pmm (T-Student) was high (85%) in the NLHS group (P˂0.05), when compared with the control (20%).

Conclusions:

The results show that NLHS at 37⁰C stimulates the immune system and increases survival against a salinity challenge at 0 ppm.