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

34 Kuroshio Biosphere : BULL. BIOL. INST. KUROSHIO Vol. 1, 2004
Parapodia rather long comparing with body width. Each parapodium sub-biramous,
with two dorsal acicula and a single ventral aciculum (Fig. 3, D-G). Dorsal cirri long and
articulated. Two notoacicula in cirrophore of dorsal cirrus, one much slender than another
(Fig. 6, F). Ventral cirrus simple subulate form, inserted midway of ventral margin of
parapodium. Neuropodial setal cone simple conical, never divided into pre- and postsetal
lobes (Fig. 3, D-E). A single neuroaciculum in neuropodial cone. Its apex extending to the
margin of neuropodial cone of a little inferior to podial apex (Fig. 3, G).
Each parapodium with 18-20 compound setae, but anterior parapodia with more or
less few setae (11-17 setae in setigers II-IV). Setiger I with seven compound setae. A
single simple seta in each parapodium from setiger VI (Fig. 3, D-E, G). Simple seta
inserted dorsal margin of parapodium (Fig. 3, G). Compound setae with hooked apex and
fine serration in proximal half of blade (Fig. 3, H-J). Median setae with longer blade than
superior or inferior setae. Serration of setae with longer blade somewhat stronger than the
others. Simple seta weakly bent and with a weakly hooked but blunt apex (Fig. 3, G, K).
ETYMOLOGY.
Named for the alternate arrangement of large and small papillae on proboscis.
Fig. 3. Synsyllidia alternata, n. Gen., n. sp.
A, anterior part, dorsal view; B, prostomium; C, proboscis, ventral view; D, right 9th parapodium, anterior
view; E, the same, posterior view; F, notopodial cirrophore in the same parapodium, with noto-acicula; G,
neuropodial aciculum and a simple seta in the same parapodium; H, superior-most compound falciger; I, median
falciger; J, inferior-most two falcigers; K, tip of simple seta. Scale, A:0.5 mm, B-D: 200 µm, E: 100 µm,
F-J: 50 µm, K: 20 µm.