The phenomenon of adoption, i.e. replacement of larvae prematurely liberated from the brood pouch of conspecifics, and kin recognition was examined in three mysid species found commonly in Tasmanian waters: Anisomysis mixta australis, Paramesopodopsis rufa and Tenagomysis tasmaniae. A new method for testing the incidence of adoption using fluoroscein dye, which enables the determination of ‘same stage’ adoptions, is described. Under field and laboratory conditions, all species practised intraspecific adoption into their own brood pouches. Under laboratory conditions the incidence of adoption was higher in T. tasmaniae than it was in the other two species. Tenagomysis tasmaniae also adopted its own young in preference to those of a conspecific. Differences in the incidence of adoption between the three species suggests a higher degree of maternal care in T. tasmaniae than in either A. mixta australis or P. rufa and may be explained by differences in anatomy, habitat conditions and predation pressure.