External Anatomy of the Female Genital (Eighth) Limbs and the Setose Openings in Myodocopid Ostracodes (Cypridinidae)

The external anatomy of various cypridinid female genital (8th) limbs is described. Scanning electron microscopy shows that each female cypridinid genital limb has a medial depression and associated pore (= spermatophore pore); over all of which a male cements a spermatophore. The limb terminates laterally in a superficially smooth rounded knob bearing an additional small opening (= lateral pore). Dorsolateral to this genital limb there are grouped setae, previously called “brush organs”, that are really paired, slit–like posterolateral openings, which are probably subdermally united to the female genital limbs. The “brush organs” of all myodocopid females also are likely to be the setose openings. The setose openings are probably homologous to the setose central lobe of male cypridinid copulatory limbs, but nothomologous to the limb–like “brush organ” described for some podocopid males. We speculate that the eggs are fertilized via the spermatophore pore associated with the attached spermatophore, and that they are released from the slightly larger and more lateral setose openings into the brood chamber of the posterodorsal area of the bivalved carapace.