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

54 Kuroshio Biosphere : BULL. BIOL. INST. KUROSHIO Vol. 1, 2004
of prostomium (Fig. 10, A). A fusiform median antenna lost during treatment after fixation
(see Fig. 10, A), but short, about 1/4 of the length of prostomium, inserted frontal margin,
judging from the sketch of living state. Palpi bi-articulated, inserted just latero-ventrally to
lateral antennae (Fig. 10, A), and as long as or a little longer than the latter. Articulation
of palpi at the site of proximal 2/5 or a little more distal. Two pairs of circular eyes dark
red in color, located latero-caudal. Anterior pair of eyes larger than posterior pair (Fig. 10,
A). Each of anterior three segments with two pairs of tentacular cirri. Dorsal tentacular
cirri on segments I-III almost in same length. Ventral tentacular cirri a little shorter than
the dorsal partners. All the appendages slender, comparing with those in other species of
the genus. Pygidium unknown.
Parapodium biramous or sub-biramous. Each parapodium with a dorsal cirrus, a
neuropodial cone, and a ventral cirrus (Fig. 10, B-D). Notopodial part of the median
parapodium with a cirrophore and a cirrostyle. Notopodial cirrophore cylindrical, not so
long but slender, with an inconspicuous constriction on the midway (Fig. 10, B-D). Each
notopodium with a single aciculum, and the tip of aciculum reached to ventral side of the
constriction. Some notopodia with a single notoseta beside the aciculum tip (Fig. 10, D).
Each median neuropodium with a single aciculum (Fig. 10, B-D). Neuropodial presetal
Fig. 10. Ophiodromus longifundus, n. sp.
A, anterior part, dorsal view; B, right 23rd parapodium (with notocirrus of short type), notocirrus missing,
posterior view; C, right 20th parapodium (with notocirrus of long type), notocirrus and all supla-acicular setae
missing, anterior view; D, right 33rd parapodium, noto- and neurocirri and all neurosetae missing, posterior view;
E, neuropodial aciculum; F, notoseta; G, superior supla-acicular compound falciger; H, inferior supla-acicular
falciger; I, superior sub- acicular falciger; J, middle sub-acicular falciger; K, inferior-most sub-acicular falciger.
Scale by A, A: 0.5 mm; Scale by F, B: 0.5 mm; C: 200 µm; D-E: 100 µm; F: 20 µm, G-K: 50 µm.