This is the published version: Allardyce, Benjamin J., Linton, Stuart M. and Saborowski, Reinhard 2010, The last piece in the cellulase puzzle : the characterisation of β-glucosidase from the herbivorous gecarcinid land crab Gecarcoidea natalis, Journal of experimental biology, vol. 213, no. 17, pp. 2950-2957. Available from Deakin Research Online: http://hdl.handle.net/10536/DRO/DU:30031463 Reproduced with the kind permissions of the copyright owner. Copyright : 2010, Company of Biologists 2950 INTRODUCTION Herbivorous terrestrial crustaceans, such as gecarcinid land crabs, consume a wide range of plant material, which is rich in cellulose and hemicellulose. Land crabs possess multiple endogenous endo--1,4-glucanases, one of the key enzyme classes involved in cellulose hydrolysis The traditional model for cellulose digestion in invertebrates reflects what is known about fungal cellulase systems. This model suggests that cellulose hydrolysis involves the synergistic activity of endo--1,4-glucanases (1,4--D-glucan-4-glucanohydrolases, EC 3.2.1.4), exoglucanases, including both cellobiohydrolases (1,4--D-glucan cellobiohydrolases, EC 3.2.1.91) and sometimes glucohydrolases (1,4--D-glucan glucanohydrolases, EC 3.2.1.74) and -glucosidases (-glucoside glucohydrolases, EC 3.2.1.21) Like fungal systems, endo--1,4-glucanases and -glucosidases appear to be key components of the cellulase systems of many marine and terrestrial invertebrate