Study on tributyrin enhancing anti periodic high temperature stress ability of gill tissue in Litopenaeus vannamei

Periodic high−temperature (PHT) has a significant effect on biological function of shrimps in aquaculture. Gill, as the respiratory and metabolic organ of shrimp, plays a key role in maintaining the osmotic balance in fish body. However, its function is easily disturbed by environmental changes such as high temperature. In order to investigate effective strategies against PHT in shrimp, we investigated the effects of tributyrin (TB) on the morphology and physiological function of gill tissue of Litopenaeus vannamei under PHT (34±1) ℃, 7 d stress. The results show that PHT stress caused significant gill tissue damage and induced oxidative stress, which in turn caused endoplasmic reticulum stress, apoptosis and osmotic regulation dysfunction. With different feeding strategies (Feeding tributyrin for 7 d before stress, feeding tributyrin every day including 7 stressed days, and feeding tributyrin for 7 d after stress), the degree of gill tissue damage decreased significantly, so did the level of oxidative stress. In addition, tributyrin positively regulated the relative expression levels of oxidative stress, endoplasmic reticulum stress, apoptosis and osmoregulation genes which were induced by PHT. In particular, daily feeding tributyrin was effective in maintaining the morphological integrity of gill tissues and stable physiological functions. The study provides important references for the strategies against environmental stress in shrimp aquaculture.