Notophyllum japonicum Marenzeller, 1879

Kato, Tetsuya & Pleijel, Fredrik, 2002, A revision of Notophyllum Örsted, 1843 (Phyllodocidae, Polychaeta), Journal of Natural History 36 (10), pp. 1135-1178 : 1159-1164

Notophyllum japonicum Marenzeller, 1879

(gures 12, 13)

Notophyllum japonicum Marenzeller, 1879: 126–127 , pl. 3, gure 1; Izuka, 1912: 200–201.

Notophyllum imbricatum: Fauvel, 1936: 59 . Not Notophyllum imbricatum Moore, 1906 .

Not Nipponophyllum japonicum: Imajima and Hartman, 1964: 67–68 , pl. 14, gures a, b (5 Notophyllum imajimai sp. n.).

Material examined. Japan: holotype ( NMW Inv. 522, in alcohol; MNZM-2713, mounted, one parapodium and two dorsal cirri), ‘ Southern Japan’ ; one specimen, Oshoro , Hokkaido, intertidal, 28 September 1994 ; one specimen, Oshoro , 1 m, 21 July 1998 ; two specimens, Otsuchi-bay, Honshu , 39ss20.7¾N, 141ss57.7¾E, 49 m, sandy mud, 7 May 1997 ; three specimens, Tsukumo Bay, Noto , Honshu, intertidal, 17 May 1995 ; seven specimens, Kominato, Honshu , intertidal, 23–25 June 1998 ; four specimens (ZIHU-1874), Aburatsubo , Misaki, Honshu, 21 June 1993 ; one specimen, Aburatsubo , Misaki, 22 June 1993 ; three specimens, Moroiso, Misaki , intertidal, 21 June 1994 ; three specimens, Araihama, Misaki , intertidal, 19 May 1996 ; two specimens, Aburatsubo, Misaki , intertidal, 19 May 1996 ; eight specimens, Shimoda, Honshu , 26–27 May 1996 ; two specimens, Sugashima Island, Toba , Honshu, intertidal, 7–8 April 1997 ; six specimens (ZIHU-1875), Shirahama , Honshu, intertidal, 19–20 April 1995 ; two specimens, Shirahama , 3–5 m, coral rubble, 15 May 1998 ; one specimen, Amakusa, Kyushu , 1 m, 10 November 1994 ; four specimens, Amakusa , 40–50 m, shell sand, 22 October 1996 . Hong Kong: four specimens, Cape d’Aguilar, Lobster Bay , 22ss12.4¾N, 114ss15.5¾E, 1 m, algal tufts, 12 July 1995 , collection of F.P.

Description. For length and width measurements versus number of segments, see gure 13; holotype complete, 9 mm long and 1.5 mm wide for 69 segments. Up to 30.5 mm long and 2.5 mm wide for 81 segments (ZIHU-1875). Body of uniform width, dorso-ventrally attened; dorsum almost completely covered by dorsal cirri (gure 12A). Prostomium rounded to pentagonal, usually pointing downwards, with antero-ventral elongation and a pair of large rounded eyes with lenses. Length of paired antennae and palps ca two-thirds length of prostomium. Median antenna about as long as prostomium, inserted between eyes. Nuchal organs with two or three lobes (gure 12A, B). Juvenile specimens (<5 mm long) with two lobes. Proboscis long, narrower than prostomium, with single rows of discoidal papillae on each side; rows absent from proximal-most part (gure 12C). Proximal part dorso-laterall y with one or two pairs of large rounded papillae on each side. Proximal and median part (>nine-tenths of total length) dorsally and ventrally covered with diOEusely distributed minute, rounded papillae, 10–16 m m in diameter; density of papillae higher on ventral than on dorsal; proximal-most part with equally high density on both sides. Distal-most part covered with large oval papillae, 60–100 m m in maximum diameter. Terminal ring smooth, without papillae. Segments 1 and 2 dorsally invisible in both juvenile and larger specimens. Tentacular cirri of segment 1 reaching ca segment 5. Dorsal tentacular cirri of segment 2 reaching ca segment 7. Ventral tentacular cirri of segment 2 reaching ca segment 6, asymmetrical, distally gradually tapered; posteriorly directed. Dorsal tentacular cirri of segment 3 reaching ca segment 7. Segment 2 with ca three compound chaetae arising from ventral tentacular cirrophores. Segment 3 with small neuropodial lobes with ca ve compound chaetae, and small ventral cirri. Segments 2 and 3 with dorsal and ventral aciculae. Dorsal aciculae absent from segments 2 to 11. Dorsal cirri of median segments broad reniform. Tips of dorsal cirri absent in both juveniles and larger specimens. Dorsal cirrophores rounded, from segment 12 with single aciculae (gure 12D, E). Notopodial capillary chaetae absent. Neuropodial lobes with ca 40 compound chaetae. Ventral cirri reniform. Pygidial cirri attened and rounded. Pygidial papilla present.

Colour. Live animals with subdued violet body and reddish violet dorsal cirri. Anterior-most two or three dorsal cirri bluish violet. Preserved specimens brown. Eyes blackish.

Biology. Swimming mature males and females (ZIHU-1874) collected with light, 20:00–22:00 h, 21–22 June 1993, Misaki, Honshu, Japan. Mature specimens also collected at Shirahama in April.

Habitat. Intertidally among barnacles, mussels, oysters and seaweeds. Subtidally on bottoms with sand and shell gravel. Intertidally to 50 m depth.

Distribution. Known from southern Japan and Hong Kong.

Remarks. Notophyllum japonicum diOEers from other Notophyllum in the combination of rounded dorsal cirrophores, slender proboscis with single rows of discoidal papillae on each side, nuchal organs with two or three lobes, and in the absence of notopodial capillaries. It is most similar to N. multicirris in the morphology of the proboscis and the dorsal cirrophores, but diOEers in having a stouter body, smaller number of nuchal lobes, and in colour and pigmentation of body and cirri.

Fauvel (1936) recorded N. imbricatum from Tôshima, Honshu, Japan. Although the description is brief, we believe his record refers to N. japonicum .

Imajima and Hartman (1964) redescribed N. japonicum based on two newly collected specimens from Ishizaki, Hokkaido, northern Japan, and designated it as type species for their new genus Nipponophyllum . The presence of notopodial capillaries, dorsally elongated dorsal cirrophores, and proboscis lacking rows of discoidal papillae, indicates that their specimens instead belong to Notophyllum imajimai sp. n. (see also section Remarks for this species).