Abstract
Immature spider crab females were treated with juvenile hormone analogs, ZR-512, ZR-619, and ZR-777. After 15 days, the ovaries were collected and prepared for electron microscopy. Many oocytes in premeiotic stages became necrotic after treatment showing chromatin condensation, intra-nuclear membrane-bound vesicles, and many electron-dense cytoplasmic bodies. Early vitellogenic oocytes, however showed little response to any of the analogs. ZR-619 and to a lesser extent ZR-777 caused the development of large spaces between follicle cells and between follicle cells and oocytes.