Various stages of the life cycle of <i>Rhizostoma luteum</i>.

(A) Planula larva with a two-layered structure; (B) Newly metamorphosed 4-tentacled scyphistoma; (C) Top view of a 6-tentacled scyphistoma; (D) Young scyphistoma with 8 filiform tentacles and prominent hypostome; (E) Intermediate 12-tentacled scyphistoma; (F) Fully developed scyphistoma with 16 filiform tentacles; (G-J) Strobilation stages of the same scyphistoma during laboratory monitoring; (G) Early strobila with developing segments; (H) Basal scyphistoma regenerating new tentacles; (I) Mid-strobila with regressing tentacles and developing ephyral segment; (J) 4-day-old strobila about to liberate one ephyra; (K) Residuum after releasing ephyra; (L) Strobila with two ephyrae. ca calyx, ed ephyra disc, hy hypostome, ml marginal lappets, ne nematocysts batteries, pod podocyst, rh rhopalium, st stalk, ten tentacle, tr tentacular ring. Scale bar 1 mm for all except (A) 20 μm and (B, C) 100 μm. Photos by T. Schwaha: A; K. Kienberger: B, C; M. Riera-Buch and A.M. Schönemann: D-L.