Fig. 9 in Echinoderes blazeji Grzelak & Sørensen 2022, sp. nov.

Fig. 9. Morphological changes of the internal yolk sac during late embryonic development of Sepia pharaonis. (A) The internal yolk sac of the embryo starts to develop at stage 20. (B) Two small Y-shaped buds protrude laterally from the back of the statocysts at stage 21. (C) Two apparent internal yolk pouches elongate backwards at stage 22. Arrow: gill. (D) Strong and enlarged internal yolk sac are like two thumb-shapes at stage 23. (E) Two laterally strong and enlarged internal yolk pouches meet together in the posterior at stage 24. (F) The internal yolk storage looks like an inverted shield with a can-shaped base and a triangle chief at stage 25. Increments of cuttlebone accumulate above the internal yolk storage. Red dashed circle: internal yolk sac. st: stage. Scale bar = 500 nm.