A female specimen of an undescribed species of Parathyonidum Heding, 1954 from Eastern Antarctica (17 mm long, preserved; NMV F84983) has 39 differentiating coelomic juveniles of uniform size (2–3 mm long) (fig. 2c). Materia et al. (1991) reported coelomic brood-protection for Neoamphicyclus materiae O’Loughlin, 2007 (as Neoamphicyclus lividus Hickman, 1962) and Staurothyone inconspicua (Bell, 1887) from SE Australia. This is a third case of intra-coelomic brood-protection by a dendrochirotid holothuroid species.