This publication contains results from the research project "Development of Genetically Improved Strain of Macrobrachium" covered by the Program on the Promotion of Sustainable Aquaculture in the ASEAN Region (previously known as Integrated Rural Aquaculture Program). It specifically includes activities from the inception of the project in 2002 up to 2005 under the Special Five-year Program on Sustainable Fisheries for Food Security in the ASEAN Region as well as research updates from 2006 to date. Project activities from 2006 to 2010 have been placed under the ASEAN-SEAFDEC Fisheries Consultative Group (FCG) collaborative mechanism with financial support from the Government of Japan Trust Fund. Dr. Koichi Okuzawa, AQD's Deputy Chief from 2005-2007, was project leader at the time the studies started until early 2007.