Huxley's line demarcates extensive genetic divergence between eastern and western forms of the giant freshwater prawn, Macrobrachium rosenbergii.

Phylogenetic analysis of representatives from 18 wild populations of the giant freshwater prawn, Macrobrachium rosenbergii, utilising a fragment of the 16S rRNA mitochondrial gene, identified two major reciprocally monophyletic clades either side of a well-known biogeographic barrier, Huxley's line. The level of divergence between the two clades (maximum 6.2%) far exceeds divergence levels within either clade (maximum 0.9%), and does not concord with geographical distance among sites. 'Eastern' and 'western' M. rosenbergii clades have probably been separated since Miocene times. Within-clade diversity appears to have been shaped by dispersal events influenced by eustatic change.