Trophoniella bastidai, SALAzAR-Vallejo, 2012

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

Trophoniella bastidai n. sp.

( Fig. 3 )

Piromis gracilis – Hartman 1961: 123, 124, pl. 29, figs 1-4, pl. 30, figs 1-9 partim.

TYPE MATERIAL. — Eastern tropical Pacific. Holotype ( LACM-AHF 2481 ), broken in 2 pieces, most chaetae broken, Chacahua Bay , Mexico, R/ V Velero III, stn 767 (15°55’00”N, 97°41’00”W), 5.5 km S off Chacahua Lagoon mouth, mud, 40-50 fathoms, 9.I.1938.

TYPE LOCALITY. — Chacahua Bay, 5.5 km S of Chacahua Lagoon mouth, in 80-100 m depth.

DISTRIBUTION. — Restricted to the type locality, Chacahua Bay, Oaxaca, Mexican Pacific coast, in 80-100 m depth. ETYMOLOGY. — This species is being named after my friend and colleague Dr J. Rolando Bastida-Zavala, as a means of appreciation and recognition of his work leading a group of polychaetologists in the Universidad del Mar, Oaxaca. Because the species was found in that Mexican state, it might promote their interest in finding more undescribed species.

DESCRIPTION

Holotype ( LACM-AHF 2481 ), broken in two pieces, matching together, without posterior end ( Fig. 3A ), pale brown, slightly reddish-brown anteriorly. Tunic without sediment grains, smooth, transparent dorsally, pale, rugose ventrally.

Body club-shaped, wider anteriorly, tapering posteriorly, 84 (44 + 40) mm long, 8 mm wide, cephalic cage 17 mm long, 52 (25 + 27) chaetigers. Body papillae mostly eroded, few remaining in chaetal lobes and body depressions, more visible in posterior region; papillae darker than body wall; dorsal papillae arranged in four longitudinal series as two dorsolateral pairs; ventral papillae arranged in two longitudinal, ventrolateral series.

Anterior end not exposed; not dissected to avoid further damage.Branchiae cirriform, slightly everted ( Fig. 3C ). Cephalic cage chaetae about as long as 1/6 body length, twice as long as body width. Chaetigers 1-2 involved in the cephalic cage ( Fig. 3B ), chaetiger 3 with long chaetae, not reaching the longer chaetae of preceding chaetigers; chaetae arranged in short dorso- and ventrolateral series, 16- 18 noto- and 14-16 neurochaetae in chaetiger 1, and 14-16 noto- and 12-14 neurochaetae in chaetiger 2. Anterior dorsal margin of first chaetiger eroded, probably with a lobe; body wall dark, exposed, two short lateral papillae remain. Anterior chaetigers with notopodial tubercles and a postchaetal row of capitate, long papillae in neuropodia ( Fig. 3B ).

Chaetiger 1 slightly shorter than chaetigers 2-3. Notopodial lobes globose in chaetigers 2-9, larger in chaetigers 3-5, shorter afterwards, visible to chaetiger 23. Chaetal transition from cephalic cage to body chaetae gradual; falcate anchylosed neurohooks starting by chaetiger 26, apparently all multiarticulate chaetae being replaced at the same time. Gonopodial lobes not visible.

Parapodia better developed in anterior chaetigers, placed on the body corners.Median neuropodia ven - trolateral.Notopodia long, lobate, with 4-6 cirriform, capitate, postchaetal papillae.Neuropodia lobes long, with 4-6 cirriform, capitate, postchaetal papillae.

Median notochaetae arranged in short, oblique series, 6-7 per bundle, as long as 1⁄₅ body width; all notochaetae multiarticulated capillaries, short articles basally and medially ( Fig. 3D ), slightly longer distally.Neurochaetae multiarticulated capillaries in chaetigers 1-25, but only distal part clearly articulated, most part of chaetae anchylosed; by chaetiger 26, all neurochaetae falcate, anchylosed, tips pale. Neurochaetae arranged in transverse series in median chaetigers, becoming oblique in posterior chaetigers, 4-6 in median chaetigers, 5 in posterior chaetigers, each subdistally tapering to a blunt (broken) tip ( Fig. 3E ), short articles present to the subdistal region.

Posterior end unknown.

REMARKS

Trophoniella bastidai n. sp. is closely allied to T. borealis n. comb. (see below). These species include large specimens with an almost smooth tunic, with notopodial lobes in some anterior chaetigers and by having anchylosed neurohooks from median or posterior chaetigers. They differ by the number of chaetae of the cephalic cage, 14-18 per bundle, in T. bastidai n. sp., against 5-7 in T. borealis n. comb.; also, T. bastidai n. sp. has larger notopodial lobes, extending through the first 10 chaetigers, whereas they are restricted to the first few chaetigers in T. borealis n. comb. The holotype of T. bastidai n. sp. was included as part of the type series of Piromis gracilis , which is now regarded as a member of Pycnoderma Grube, 1877 (Salazar-Vallejo 2011a:41). The combination of a tunic without sediment cover, the presence of notopodial lobes, and the posterior start of falcate, anchylosed neurohooks indicates that it deserves an independent specific status.

Figures

FIG. 3. — Trophoniella bastidai n. sp., holotype (LACM-AHF 2481): A, lateral view; B, anterior end, lateral view; C, anterior end, ventral view;D, chaetiger 11, notochaetae (insert:basal and medial notochaetal regions);E, chaetiger 31, neurochaetae (inserts:neurochaetal broken tips). Scale bars: A, 6.7 mm; B, 2.6 mm; C, 1.6 mm; D, 185 µm; E, 270 µm.