Note
Transmission electron microscopy reveals that the ovaries of
Ferosagitta hispida contain four somatic tissues. A myoepithelial ovary wall,
continuous with a thin layer of peritoneocytes lining the coelomic cavity,
encloses a fluid-filled ovarian space in which oocytes develop. Lamellar extensions
of a "follicular reticulum" branch throughout the ovarian space and
ensheath developing oocytes. This tissue has been overlooked in most previous
studies of chaetognath ovaries.