HESIONIDAE (ANNELIDA, POLICHAETA) FROM JAPAN. I. by Hiro ...

70 Kuroshio Biosphere : BULL. BIOL. INST. KUROSHIO Vol. 1, 2004
Hartmann-Schröder (1971) defined two subfamilies, Hesioninae and Microphthalminae, in
the family Hesionidae. Struwela and Uncopodarke are, however, completely connected the
two subfamilies, by the reasons mentioned above. It seems, therefor, to be better that the
subdivision of the family are not applied.
Uncopodarke intermedia, Gen. et sp. nov.
(Figs. 16-17)
MATERIAL EXAMINED.
Nachi-Katsuura Town (Kii Peninsula), Nachi Bay, 2 m deep, sandy bottom, 27 Sept.
1988 (holotype); ditto, 8 m deep, sandy bottom, 27 Sept. 1988 (paratype).
DESCRIPTION.
Body colorless, 3.6 mm long with 31 setigers in the holotype, 5 mm long with 48
setigers in the paratype. Body width (excl. parapodia) anteriorly 260 µm, middle 280 µm,
and posteriorly 160 µm in the holotype. Those in the paratype, 300 µm, 370 µm, and 200
µm respectively. Body depressed dorso-ventrally, ca. 150 µm thick.
Prostomium sub-conical, wider than long, with a pair of lateral antennae and a pair of
minute palpi. Median antenna wanted. Lateral antennae subulate in form, somewhat shorter
than prostomium (Fig. 16, A-C). A pair of palpi (only in holotype) as minute papillae,
inserted latero-ventrally to lateral antennae, and not observable in dorsal view (Fig. 16, A).
A pair of minute eyes situated near the widest corners of prostomium (Fig. 16, A).
Proboscis not protruded in both specimens.
Each of the first three segments with two pairs of tentacular cirri, same as the species
of Microphthalmus (Fig. 16, A-B). All three pairs of dorsal tentacular cirri markedly
longer than their own ventral partners. Dorsal tentacular cirri of segments II and III longest,
and almost same length each other, and much longer than those of segment I. Among
ventral tentacular cirri, those of segment II longest. Ventral tentacular cirri of segment II as
long as a half of the dorsal ones. Ventral tentacular cirri of segment III shortest.
Setae present from the fourth segment (Fig. 16, A-B). Dorsal cirri of the first setiger
not prominent (Figs. 16, A-B, F-G). Dorsal cirri gradually long towards posterior setigers,
and enough long in the fifth setiger (segment 8), but much shorter than dorsal tentacular
cirri (Fig. 16, A). Posterior end with a pair of anal cirri and a fan-shaped anal lamella
(Fig. 16, D-E). Anal cirri short, extending to the posterior margin of anal lamella. Anal
lamella with an entire margin, without a mid-posterial incision nor marginal fringes.
Parapodia of the first setiger (segment 4) uniramous, without prominent dorsal cirri,
nor notopodial acicula nor setae, but with ventral cirri (Fig. 16, F-G). All the parapodia,
except for in the first setiger, almost in same form. Each parapodium with a long dorsal
cirrus and a short ventral cirrus. Notopodial cone not prominent, with a small fascicle of
diminished setae situated on the inferior bases of notocirrus (Fig. 17, A, C, G). Each
neuropodial cone well developed, consisting of a long presetal lobe and a small conical
postsetal lobe. Presetal lobe cylindrical with more or less truncated distal end, and thrust
with a fine aciculum to distal part near the tip. A stout aciculum extending to the tip of a