Scolelepis (Scolelepis) variegata Imajima, 1992

Zhou, Jin, Ji, Weiwei & Li, Xinzheng, 2009, A new species of Scolelepis (Polychaeta: Spionidae) from sandy beaches in China, with a review of Chinese Scolelepis species, Zootaxa 2236, pp. 37-49 : 45-46

Scolelepis (Scolelepis) variegata Imajima, 1992

Figure 4

Scolelepis (Scolelepis) variegata Imajima, 1992: 20 –22, figs. 3a–h.

Material examined. MBMCAS 228678 (1 spm), 122°40΄ E, 31°15΄ N, Changjiang River Estuary, sandy mud with debris, 33 m, 30 Jun 1986; MBMCAS 228909 (1 spm), 122°45΄ E, 31°45΄ N, Changjiang River Estuary, sandy mud, 37 m, 13 Dec 1985, coll. Xianqiu Ren; MBMCAS 228912 (1 spm), 121°45΄ E, 31°30΄ N, East China Sea, sandy mud, 10.5 m, 21 Oct 1959; MBMCAS 228988 (2 spms), 121°15΄ E, 38°00΄ N, Yellow Sea, sandy mud, 44 m, 28 Jan 1959; MBMCAS 228990 (2 spms), 123°00΄ E, 37°00΄ N, Yellow Sea, mud, 30 m, 18 Apr 1959; MBMCAS 228996 (1 spm), 123°00΄E, 31°45΄N, Changjiang River Estuary, sandy mud, 38 m, 4 Mar 1986, coll. Xianqiu Ren; MBMCAS 228997 (1 spm), 122°40΄ E, 31°15΄ N, Changjiang River Estuary, silty mud, 37 m, 15 Oct 1985.

Description. Prostomium elongated, with pointed anterior margin; posterior with rounded swelling just behind 2 pairs of small eyes. Occipital tentacle absent. Two pairs of eyes arranged in a transverse row. Peristomium distinct from setiger 1, forming well-developed lateral wings ( Fig. 4 A).

Parapodia of setiger 1 well developed, with small, oval notopodial and neuropodial postsetal lamellae; capillary setae present on neuropodia, lacking on notopodia ( Fig. 4 B). Branchiae present from setiger 2, continuing posteriorly to end of body. Notopodial postsetal lamellae completely fused with branchiae from setiger 2 to setiger 29, thereafter lamellae separated from branchiae, posterior notopodial lamellae triangular with elongated pointed tips ( Fig. 4 C–D). Notopodial postsetal lamellae long, narrow with slight serrations in anterior setigers, gradually reduced to subtriangular lamellae in middle and posterior region. Notopodial presetal lamellae rounded in anterior setigers, becoming reduced in posterior setigers. Neuropodial postsetal lamellae rounded in anterior setigers, becoming low and round in posterior setigers. Neuropodial presetal lamellae thick and round, from posterior setigers; smaller than corresponding neuropodial postsetal lamellae.

All anterior setae capillaries, arranged in two rows on both rami. Anterior row thick, heavily granulated, posterior row thin capillaries without obvious sheaths ( Fig. 4 E–H). Neuropodial hooded hooks from setigers 24–27, bidentate, with distinct secondary tooth ( Fig. 4 I), 6–16 in a series, accompanied by capillaries. Notopodial hooded hooks absent.

Pygidium missing in present material.

Remarks. The specimens agree well with previous descriptions and illustrations. Scolelepis (S.) variegata Imajima, 1992 is unique among Scolelepis from China in its relative plump body and lack of notosetae on setiger 1. Additionally, the branchiae and notopodial lamellae in the anterior part of the body are completely fused. The species is newly reported for the Chinese Scolelepis fauna.

Distribution. China (Yellow Sea, East China Sea; 10.5–44 m); Japan.

Figures

FIGURE 4. Scolelepis (Scolelepis) variegata Imajima, 1992. A, anterior end, dorsal view; B, parapodia of setiger 1, anterior view; C, parapodia of setiger 2, anterior view; D, parapodia of setiger 31, anterior view; E, notopodial seta from anterior row of setiger 4; F, notopodial seta from posterior row of setiger 4; G, neuropodial seta from anterior row of setiger 4; H, neuropodial seta from posterior row of setiger 4; I, neuropodial hooded hook from setiger 30. Scales: A, 600 μm; B – D, 120 μm; E – I, 250 μm.