Аннотация:Onchidorididae (Doridoidei, Nudibranchia) is the family of nudibranch mollusks
with spicules in their integuments which bear supporting and protective functions.
Despite that general morphology and arrangements of the spicules well described, data
of localization, internal morphology and correlations between spicules morphology and
strength are fragmentary. This study describes in detail the spicules of three dorids Acanthodoris pilosa (Abildgaard in Müller, 1789), Adalaria proxima (Alder et Hancock,
1854), Onchidoris muricata (Muller, 1776) inhabiting in the White Sea.
The collection of material was carried out in the summer period 2016–2019 in
the Kandalaksha Bay of the White Sea in the vicinity of the N.A. Pertsov White Sea
Biological Station. During the research classical methods of light and scanning electron
microscopy were used.
As a result of the study of spicular morphology there were described four types
spicules (monoactine, diactine, triactine, tetractine) for all studied species, as well as
spherules, which have been found only in papillae of A. pilosa. The external and internal
morphology of spicules have been studied by scanning electron microscopy. Three types
of internal organization of the spicules have been identified – monolithic, mixed, and
concentric. There was no find reveal correlation between the type of the spicules and
their internal structure.
For the first time have been proposed the correlation between the general morphology, thickness of the tracts and thickness of the integuments: the density of the integuments does not depend only on the number of the spicules, but also on the character of
their colocalization and the thickness of the layer in which they are located. The specula
networks of body A. pilosa has thick covers and doesn’t have elongated spicules in
the papilla, but O. muricata and A. proxima have vertical tracts with elongated spicules
in the papilla with thin cover.
This work was supported by the RFFR grant nos. 18-05-60158, 18-34-00251.