Abstract:

Litopenaeus vannamei is one of the three most highly produced prawn species globally. However, increasing breeding density has led to decay and decomposition of feed residues and excrement of Litopenaeus vannamei. This process results in abnormal fluctuations of nutrient elements within the water, particularly nitrogen and phosphorus, thereby affects the water quality of aquaculture water, causing diseases and deaths of Litopenaeus vannamei. This experiment observed and compared the changes in algae, nitrogen phosphorus ratio, pH value, dissolved oxygen content (DO), ammonia nitrogen content, and nitrite content in three culture ponds of Litopenaeus vannamei, analyzed and explored the relationship between water color changes and algae, as well as the influence of nitrogen phosphorus ratio on water quality, which provided theoretical support for aquaculture production. In the early stage of Litopenaeus vannamei, appropriate fertilization should be applied, and in the later stage of farming, photosynthetic bacteria, Bacillus, EM bioactive bacteria should be added appropriately. Scientific feeding and oxygenation should be carried out to maintain good water quality in the pond.

Key words: Litopenaeus vannamei, nitrogen phosphorus ratio, algae, pH value, dissolved oxygen content, ammonia nitrogen, nitrite