Trophoniella tumbensis (Hartmann-Schröder, 1962) SALAzAR-Vallejo, 2012

SALAzAR-Vallejo, Sergio I., 2012, Revision of Trophoniella Hartman, 1959 (Polychaeta, Flabelligeridae), Zoosystema 34 (3), pp. 453-519 : 453-519

Trophoniella tumbensis (Hartmann-Schröder, 1962) n. comb.

( Fig. 27 )

Pherusa tumbensis Hartmann-Schröder, 1962: 153 , 154, figs 199, 200. — Rozbaczylo 1985: 160. — Rozbaczylo & Moreno 2005: 122-124, fig. 1.

TYPE MATERIAL. — Southeastern Pacific Ocean. Holotype of Pherusa tumbensis ( ZMH 15441), NW Tumbes Peninsula (Talcahuano, Concepcion), Chile, in sand, with holothurians, 8.XII.1958, Jeldes (in label; in publication: Hulot).

ADDITIONAL MATERIAL. — Central eastern Pacific Ocean. An anterior fragment ( LACM-AHF 2503 ), R/ V Velero III, stn 69 (00°09’S, 91°23’W), Tagus Cove, Albermarle Island , Galápagos, rocky shore, tide pools, 11.II.1933 (58 mm long, 8 mm wide, cephalic cage 11 mm long, 50 chaetigers; first neurohooks in chaetigers 6 or 7, 1 on each side) .

DISTRIBUTION. — Originally described from theTumbes Peninsula (Talcahuano, Concepción), Chile. Fauchald (1972: 414) wrongly listed Tumbes, Peru, as the type locality. The species has been found from Galápagos to southern Chile, in shallow-water sediments or in mixed bottoms.

DESCRIPTION

Holotype ( ZMH 15441), without posterior end ( Fig. 27A ). Body grayish; fusiform, cylindrical, tapering posteriorly, 80 mm long, 9 mm wide, cephalic cage 12 mm long, 53 chaetigers. Tunic pale, with sediment cover dorsally ( Fig.27C ), extending laterally, reaching neuropodia; ventral surface without sediment. Body wall black.Body papillae mostly eroded distally, dorsally difficult to see, ventrally arranged in four longitudinal rows or double papillar scars.

Anterior end not exposed; not dissected to avoid further damage.

Cephalic cage chaetae as long as body width. Chaetigers 1-4 involved in the cephalic cage; chaetae arranged as short dorsolateral series. Chaetiger 1 with 12 noto- and 10 neurochaetae, chaetigers 2 - 3 with 10 chaetae per bundle, chaetiger 4 with nine noto- and eight neurochaetae.Anterior dorsal margin of first chaetiger papillated, with a short, conical, bifid lobe, directed ventrally. Chaetigers 2-6 with two large dorsal papillae per segment, decreasing in size posteriorly, each as a rounded lobe, directed anteriorly. Chaetigers 1-3 of about the same length. Chaetal transition from cephalic cage to body chaetae abrupt; short, dark, anchylosed neurohooks start in chaetiger 7 ( Fig.27B, D ). Gonopodial lobes not seen.

Parapodia poorly developed, chaetae emerging from the body wall. Parapodia lateral; median neuropodia ventrolateral. Noto- and neuropodia as short transverse slits carrying chaetae; notopodia with two postchaetal papillae, neuropodia with three smaller postchaetal papillae.

Median notochaetae arranged in short transverse series, 9-10 per bundle, as long as ¼-1⁄₅ body width; all notochaetae multiarticulated capillaries, mostly broken distally, each with articles short, becoming slightly longer distally, tips falcate, hyaline ( Fig. 27E , inserts). Neurochaetae multiarticulated capillaries in chaetigers 1-6; anchylosed neurohooks straight, dark brown, from chaetiger 7, arranged in transverse series, 5-6 per bundle ( Fig. 27F ), with short anchylosed articles or rings basally and medially, subdistally straight, blade pale, finely obliquely striated, tip entire, falcate, surface rough.

Posterior end unknown.

REMARKS

Trophoniella tumbensis n. comb. is very similar to T.americana n. comb. There are two main differences between them: T. tumbensis n. comb. has more abundant notochaetae (8-10) than T. americana n. comb (3-5), and its body wall is grayish, whereas it is pinkish or pale in T. americana n. comb.

In the original description (Hartmann-Schröder 1962: 154), it was stated that neurohooks start in chaetiger 8, but they actually start in chaetiger 7. The difference could be explained because one side of the anterior end of the holotype was regenerating, without many chaetae, and this could confuse the chaetiger count. The falcate notochaetae are detectable, when present, using the stereo microscope because their tips catch some foreign materials; however, many chaetae are broken and this feature was overlooked in the original description.Likewise, because the tips are so fragile, it would be of little use to emphasise their usage as a diagnostic or key feature.

Figures

FIG. 27.— Trophoniella tumbensis (Hartmann-SchrÖder, 1962) n. comb., holotype (ZMH 15441):A, lateral view; B, anterior end, lateral view; C, anterior end, dorsal view; D, anterior end,ventral view, tunic removed to seek gonopodial lobes; E, chaetiger 13,notopodium (inserts: basal and distal notochaetal regions, and notochaetal tip); F, chaetiger 10, neurohooks. Scale bars: A, 2.6 mm; B, 1 mm; C, 2.3 mm; D, 1.5 mm; E, 100 µm; F, 45 µm.