Whether a horseshoe crab survives having its blood drawn depends on a variety of factors. The amount of blood that can be extracted from each horseshoe crab is usually 50 ml. This amount of blood has little impact on the life safety of horseshoe crabs, and they can usually recover within 7 days. However, 5% to 20% of horseshoe crabs die because their blood is drawn.

In addition, although the act of drawing blood may not threaten the lives of horseshoe crabs, it will affect them reproductive capacity. According to statistics, even if the blood volume and hemocyanin of horseshoe crabs whose blood has been extracted return to normal levels, their reproductive capacity will still drop by about 50%. It takes 8 to 13 years for a horseshoe crab to mature. Therefore, frequent blood collection may have a long-term impact on the reproduction of its population.