Sabellaria chandraae

Nishi, Eijiroh, Bailey-Brock, Julie Helen, Santos, Andre Souza Dos, Tachikawa, Hiroyuki & Kupriyanova, Elena K., 2010, Sabellaria isumiensis n. sp. (Annelida: Polychaeta: Sabellariidae) from shallow waters off Onjuku, Boso Peninsula, Japan, and re-descriptions of three Indo-West Pacific sabellariid species, Zootaxa 2680, pp. 1-25 : 7-10

Sabellaria chandraae de Silva, 1961

Figs. 4 (A–H), 5 (A–E), 6 (A–E).

Sabellaria chandraae de Silva, 1961:188; Kirtley, 1994: 55 –56.

Material examined. Paratype BMNH (= NHM) 62-14-61, one specimen without tube, Galle Face, Colombo, Sri Lanka, examined by Kirtley in 1973.

Description. Paratype, 12 mm long, 2 mm wide at widest part of opercular crown, 1 mm wide at parathoracic chaetigers. Cauda ca. 2 mm long and bent back on ventrum. Body of preserved worms brown.

Anterior end of opercular stalk separated into two symmetrical lobes ( Fig. 5 B, C). Lobes narrowing anteriorly, sloping posteriorly towards dorsal midline ( Fig. 5 A, B). Operculum dish-shaped, flat to slightly concave.

Paleae bright yellow or light brown, arranged in three rows (outer, middle, inner) on each lobe. Outer paleae curved outward from longitudinal axis of shaft ( Fig. 5 B), inner surface of their blades with ca. 40–50 fine, closely-spaced thecal bands. Outer paleae with 3–4, up to 5 distal teeth on either side, in some paleae the number asymmetrical, e.g., 3 and 4, 4 and 5 ( Fig. 4 , 6 A, E). A pilose (i.e., denticulate with 2–4 small lateral teeth on each side) median plume emerging from the base or middle of central tooth ( Figs. 4 F, G, 6 A, B). Pilose median plume with 5 to 10 small lateral spines on its side ( Figs. 4 G, 6 E). Some median plume spines destroyed, one or two small lateral teeth on median plume may present in some outer paleae. Middle paleae of long and short kinds, 4 to 5 long forms and 5–6 short forms ( Figs. 4 A–D, 6 B, C), blades of long forms laterally compressed with knife-like edges and weakly recurved blunt tips ( Figs. 4 F, 6 B). Inner paleae terminating with moderately sharp tips ( Figs. 4 H, 6 D). One or two pairs of nuchal spine semi-transparent and straight, with blunt tips.

Anterior outer margin of opercular crown with 7–9 fleshy conical papillae in a single row on each side ( Fig. 5 A, B). Ventral margin of buccal cavity with over 30 longitudinal rows of feeding tentacles on each side. Building organ (bo) U-shaped, with conical cirri, forming upper lip on ventral side. Feeding tentacles pale or with brown pigments, extending beyond the length of the operculum.

Three parathoracic chaetigers (pt) with 5–10 stout, oar-shaped chaetae and spine-like companion chaetae in 2 or 3 rows on each neuropodium and ca. 10 chaetae on each notopodium. Abdominal region with 21 chaetigers. Ten anterior-most abdominal chaetigers with long dorsal branchiae diminishing in size posteriorly; branchiae absent in most posterior chaetigers ( Fig. 5 E). Eyespots not observed in preserved specimens.

Variation. The outer paleae ca. 0.4 mm long and ca. 0.1 mm wide. Number of these paleae 22–24 on each side. The median plume not seen in some outer paleae. The short kinds of medium paleae rounded.

Type locality. Colombo, India.

Tube. Not available for examination.

Distribution. Coast of India.

Remarks. The nuchal spines are present in the paratype ( Fig. 5 D). Based on Kirtley (1994), the numbers of distal lateral teeth of outer paleae in S. chandraae and S. ranjhi are very similar, and these species are distinguished by the shape of the middle (short) paleae and inner paleae (Kirtley's note on page 56 states that S. ranjhi have more distal teeth on each side of plume than S. chandraae ). Based on the examination of paratype of S. chadraae , we suggest possible synonymy of S. chandraae and S. ranjhi because of close similarity of paleae characters and geographic distribution of these two species (around India and adjacent waters). However, the final decision regarding the synonymy should be made after careful comparison of type specimens of both species. Unfortunately, obtaining old type material from the collections in Pakistan and India is very difficult and our search for the type material of S. ranjhi has been unsuccessful.

Figures

FIGURE 4. Sabellaria chandraae de Silva, 1961, NHM- 62 - 14 - 61. Anterior part (A), upper view of crown (B), lateral view of head (C), dorsal view of crown (D), middle long paleae (E), outer paleae (F), close-up view of tip of outer paleae (G), middle paleae (H). Scale 1 mm (A – D), 0.1 mm (E, F, H), 0.03 mm (G).

FIGURE 5. Sabellaria chandraae de Silva, 1961, NHM- 62 - 14 - 61. Lateral (A), dorsal (B), and ventral (C) views of the anterior part, close-up of dorsal crown showing straight nuchal spines (D), posterior part (E). Scale 0.5 mm (A – C, E), 0.25 mm (D).

FIGURE 6. Sabellaria chandraae de Silva, 1961 paleae, paratype NHM- 62 - 14 - 61. Outer paleae (A), close-up of tips of outer paleae (B), middle long paleae (C), middle short paleae (D), inner paleae (E). ct: central tooth, ldt: lateral distal tooth, p: pilose plume, plt: pilose lateral tooth. Scale 0.1 mm (A, C – E), 0.02 mm (B).