Odontosyllis liniata Hartmann-Schröder, 1962

Verdes, Aida, Pleijel, Fredrik & Aguado, Teresa, 2011, A new species of Odontosyllis Claparède, 1863 (Annelida, Syllidae) with re-descriptions of O. liniata Hartmann-Schröder, 1962 and O. gymnocephala Hartmann-Schröder, 1965, Zootaxa 3095, pp. 27-38 : 30-32

Odontosyllis liniata Hartmann-Schröder, 1962

( Fig. 2 A–E)

Odontosyllis liniata Hartmann-Schröder, 1962: 125 , plate IX, figs. 53–56.

Material examined. Peru: 3 paratypes ( ZMH P- 19652). El Camotal Island, La Punta, Callao; 3 m deep, among Macrocystis rhizoids and sandy sediments. Santa Island, Coishco Bay, north of Chimbote; 9 m deep, muddy sediments. 29 May 1956. Coll. G. Hartmann-Schröder.

Description. Longest paratype (ZMH P-19652) complete specimen, 3 mm long, 0.3 mm wide, with 14 chaetigers. Body cylindrical, long and slender. Colour pattern on anterior body region consisting of a transverse band and a dark area, on front edge and front and rear corners of each segment (fide Hartmann-Schröder, 1962). Prostomium oval, four eyes in trapezoidal arrangement, anterior pair slightly larger than posterior ones. Palps broad, fused at base, shorter than prostomium. Antennae lanceolate, longer than prostomium and palps together; median antenna inserted between anterior eyes, extending to fourth segment; lateral antennae inserted near anterior margin, shorter, less than half length of median antenna ( Fig. 2 A). First segment shorter than subsequent segments, anterior margin prolonged, partially covering the prostomium. Occipital flap absent ( Fig. 2 A). Dorsal tentacular cirri similar in length and shape to median antenna; ventral pair shorter, similar in length to lateral antennae. Dorsal cirri lanceolate, longer than parapodial lobes, similar in shape and length to lateral antennae; granular material inside all cirri ( Figs. 2 A, B). Ventral cirri wide, triangular, reaching as far as parapodial lobes ( Fig. 2 B). Chaetal fascicle with 15– 16 heterogomph compound chaetae; shafts provided with spines on distal margin. Compound chaetae with short, triangular, unidentate blades, or slightly bidentate with a thin and small proximal tooth; blade edge with short spines, dorso-ventrally graduated in length from dorsal 15 m to ventral 13 m ( Fig. 2 C). Solitary dorsal simple chaeta in posterior parapodia, slender, unidentate, with minute serrations on margin ( Fig. 2 D); ventral simple chaetae not observed. Two aciculae on each parapodium, distally blunt ( Fig. 2 E). Pharynx through about four segments, surrounded by eight papillae, denticled arc with 12 small teeth (fide Hartmann-Schröder, 1962). Proventricle long and slender, through about six to seven segments, with about 50 muscle cell rows (fide Hartmann-Schröder, 1962). Pygidium conical, with two anal cirri, slender, filiform, similar in length to dorsal cirri (fide Hartmann-Schröder, 1962).

Remarks. All specimens poorly preserved. The holotype was not found and the longest paratype was described. The length of pharynx and proventricle as well as the compound chaetae observed in O. liniata are very similar to those of O. ctenostoma Claparède, 1868 , although O. liniata antennae and cirri are lanceolate, instead of digitiform. Additionally, the number of teeth of the trepan is different, O. liniata having 12 and O. ctenostoma 6–8. Odontosyllis liniata compound chaetae, aciculae and number of teeth of the denticled arc are also similar to those of O. setoensis , although the latter has also distally trilobed aciculae.

Figures

FIGURE 2. Odontosyllis liniata Hartmann-Schröder, 1962. Paratype ZMH P- 19652. A: Anterior part, dorsal view; B: Midbody parapodium; C: Compound chaetae, midbody chaetiger (chaetae arranged dorso-ventrally from left to right); D: Dorsal simple chaeta, posterior chaetiger. E: Aciculae, midbody chaetiger. Scale A 0.134 mm; B 0.07 mm; C – E 14 µm.