ISSN 1063-0740, Russian Journal of Marine Biology, 2006, Vol. 32, No. 5, pp. 299–301. © Pleiades Publishing, Inc., 2006.
Original Russian Text © E.A. Ponomarenko, O.M. Korn, 2006, published in Biologiya Morya.
First Record of a Facetotectan Crustacean
in Plankton of Peter the Great Bay, Sea of Japan
E. A. Ponomarenko and O. M. Korn
Institute of Marine Biology, Far Eastern Division, Russian Academy of Sciences, 690041Vladivostok, Russia
Received April 12, 2006
—Nauplii V of the rare crustacean
Itô, 1989, belonging to the infraclass Facetotecta
were recorded in the plankton of Peter the Great Bay (Sea of Japan) for the ﬁrst time. The larvae were probably trans-
ported in summer from the coastal waters off Japan. Scanning electron microscopic observations revealed previously
unknown morphological characteristics of these larvae: three pairs of pore ﬁelds on the dorsal side of the carapace
and the presence of processes covered with thickened setae and located at the base of mandibles.
Hansenocaris furcifera, Facetotecta, larvae, Peter the Great Bay
Schematic view of the ﬁfth stage nauplius of
. (A) dorsal side of the head shield, arrowheads show
the position of pore ﬁelds; (B) antennula.
The infraclass Facetotecta is the only taxon of crus-
taceans known exclusively from larval stages; there is
still no information on adult animals belonging to this
group. The group comprises small (250–620
crustacean larvae living in a marine environment and
showing a planktotrophic pattern of development. Lar-
val development in Facetotecta, as is the case in some
parasitic Cirripedia, comprises ﬁve naupliar instars
(y-nauplius) and one cypris stage (y-cypris) [2, 4, 5].
To date, the infraclass Facetotecta includes six
described species belonging to the single genus