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

48 Kuroshio Biosphere : BULL. BIOL. INST. KUROSHIO Vol. 1, 2004
REMARKS.
The species of Ophiodromus with long cirrophores of notopodia are O. angustifrons
(Grube, 1878), O. latifrons (Grube, 1878), O. berrisfordi Day, 1967, and Nereimyra
blacki Knox, 1960. But the only species with very short median antenna is O. berrisfordi.
N. blacki may be a member of the genus, with the median antenna broken off. N. blacki
with rather many notosetae, and a remarkable constriction on the notopodial cirrophore. The
new species without notosetae on all parapodia, and without constrictions on all notopodial
cirrophores. The new species surely near O. berrisfordi from South West Africa. However,
O. berrisfordi with minute papilliform median antenna, instead of minute spherical one,
with a conspicuous constriction on the distal part of cirrophore of notopodium, instead of
devoid of constrictions, and with long triangular presetal lobe of neuropodium, instead of
nipple-like spherical projection of presetal lobe (cf. p. 41).
Spherical minute median antenna resembles to Podarke angustifrons by Takahashi
(1941) from Palao Islands, but his Hesionid has a short notopodial cirrophore and has
"very small furcate dorsal bristles" (p. 184).
ETYMOLOGY.
Named from the Japanese names of commensal hosts, the Spatangoid, Brissus
latecarinatus and B. agassizii. The former called "minami-oh-bunbuku", and the latter
called "oh-bunbuku" in Japanese.
Ophiodromus constrictus, sp. nov.
(Fig. 8, Pl. 1, fig. 4)
MATERIAL EXAMINED.
Holotype: Sabiura, Kushimoto, Wakayama Prefecture, 12m, SCUBA diving, Sept. 22,
1992, K. Nomura, collector.
Paratype: the same locality, 10m, SCUBA diving, Sept. 23, 1994, K. Nomura,
collector, 1 specimen.
DESCRIPTION.
Body uniformly dark brown, with a central paler area on prostomium (Pl. 1, Fig. 4).
Holotype with 50 setigers, 17 mm long, 3.5 mm wide including setal fascicles, 2.5
mm wide including parapodia, and 1.25 mm wide excluding parapodia. Paratype without
posterior part, with 44 setigers, 21 mm long, 5 mm wide including setal fascicles, 3.2 mm
wide including parapodia, and 1.6 mm wide excluding parapodia.
Prostomium hemi-circular or sub-hexagonal, wider than long, with three antennae,
paired palpi, and two pairs of eyes (Fig. 8, A). A pair of lateral antennae longer than the
length of prostomium, inserted frontal margin of prostomium (Fig. 8, A). A fusiform
median antenna short, one fourth of length of the laterals, inserted frontal margin of
prostomium. Palpi bi-articulated, inserted nearby lateral antennae (Fig. 8, A), and as long
as the latter. Articulation of palpi at the site of proximal 1/3 to 1/4. Two pairs of eyes
whitish in color, located lateral corners. Anterior pair of eyes larger than posterior pair, and