Most freshwater mussels have larvae (glochidia in Unionidae, Margaritiferidae and Hyriidae) which are usually parasitic on fishes and occasionally amphibians. Larval parasitism is widely accepted as a dispersal mechanism to maintain populations within freshwater ecosystems. Documenting diversity in larval characteristics, mechanisms of release and infestation strategies are important to taxonomy and, inherently, conservation assessment and management. In this study, we provide comparative diversity on glochidia of Australasian Hyriidae, including new data from seven species. The smallest glochidia examined were Cucumerunio novaehollandiae, Hyridella australis and Echyridella aucklandica, with mean shell lengths of 56.5, 75.6 and 102.0 micrometres, respectively. Hyridella glenelgensis, Hyridella narracanensis, Hyridella drapeta (Qld), Echyridella menziesii and H. drapeta (Victoria) were larger, with mean shell lengths of 249.3, 258.0, 274.5, 301.0 and 331.0 micrometres, respectively. Glochidia of C. novaehollandiae, H. australis, H. drapeta (Qld), H. glenelgensis and H. narracanensis all have bifurcated larval teeth (two sharp cusps with a common base) on each valve, which vary in length and degree of separation between each cusp. Larval teeth in H. drapeta (Victoria) are s-shaped with tripartite cusps and, in E. aucklandica and E. menziesii, larval teeth terminate to a singular or tripartite cusp in each valve. Only E. menziesii possesses a larval thread. Glochidia of C. novaehollandiae are released singularly whilst those of E. menziesii are released singularly and in 'amorphous mucus conglutinates' (to facilitate passive entanglement). The other species examined in the study release glochidia in functional 'mesoconglutinates'. Hyridella glenelgensis and H. narracanensis, both listed as threatened species, exhibit siphon colour change, enlargement and behaviours associated with host luring attraction during glochidia release, whereas other species do not. This study adds to the growing body of knowledge on the fascinating life history strategy in a group of freshwater bivalves which are in serious decline in Australasia and globally.