elaboration in southern African and Indian Ocean Fissurellidae (Mollusca: Prosobranchia) with descriptions of two new genera and one new species.
The fine structure of the newly discovered propodial
ganglia of the veliger larva of the nudibranch Oncitidoris bilamellata.
Patches of 3 to 6 faint, blue-green fluorescent cells were reliably located in the propodial region of the foot of larvae from all of these groups (Fig.
In these larvae, the largest concentrations of fluorescent cells were again found in the propodial regions of the foot.
Sensory neurons in the anterolateral propodial ganglia of veligers of the nudibranch Onchidoris bilamellata are depolarized by a soluble settlement cue that is derived from barnacle prey of adult O.
Larvae of the nudibranch Onchidoris bilamellata were reported to detect a water-borne cue from the barnacle prey of the adult nudibranch via a pair of lateral propodial
"ganglia"; however, the barnacle factor induces only reversible settlement behavior, but not metamorphosis, which is dependent on a surface-bound cue (Arkett et al., 1989).
The various fibers of the medial pedal muscle insert on pedal epithelium underlying the operculum, on intrinsic muscle fibers associated with the crawling surface of the foot, and on the large propodial
As an adult, the specimen presents a well-ossified sutured skull, fully formed teeth exhibiting noticeable ridges on their enameled crowns, and capitulum and tuberosity or trochanter differentiated on propodials. However, it preserves the cervical vertebrae without fused ribs, almost flat articular facets of the vertebral centra, and the atlas and axis fused but with indication of the suture between them, all of which suggest traces of a juvenile stage.
Both left fins are articulated with the girdles while the right ones were removed during the mining, and only the propodials were found on the surroundings of the excavation site (Figure 2).