a, b C. xamachana medusae (5–12 cm diameter) resting on umbrella apex (white arrow) with oral arms (cyan arrows) facing up, observed by authors in the natural mangrove habitat in Key Largo, Florida (USA). Images courtesy of A. Morandini. c–f Cassiosome nests (pink arrows) observed as white bulging spots at the termini of vesicular appendages (green arrows) off-branching from areas of frilly digitate cirri (black arrows) on medusa oral arms (cyan arrows). Some cassiosome nests appear less full than others. Scale bars: a = 2 cm; b = 5 cm; c, d = 1 mm; e, f = 0.5 mm.