The shrimp farmers in the country, especially in Andhra Pradesh, should not cultivate, or culture P. Monodon alone as there is a shift in the international market, and they should take up culture of L.Vannamei as well on a large scale, according to Mr L. Sa-tyanarayana, the President of the All-India Shrimp Hatcheries' Association (AISHA). He was addressing a press conference here on Monday.