1 23 Aquaculture International Journal of the European Aquaculture Society ISSN 0967-6120 Volume 20 Number 1 Aquacult Int (2012) 20:51-70 DOI 10.1007/s10499-011-9441-0 From production to consumption: a case study of tilapia marketing systems in Bangladesh Nesar Ahmed, James A. Young, Madan M. Dey & James F. Muir