Trophoniella lindae, SALAzAR-Vallejo, 2012

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

Trophoniella lindae n. sp.

( Fig. 20 )

Siphonostomum cariboum – Ehlers 1887: 158-161, pl. 42, figs 6-9, pl.43, fig.1 (non Grube & Ørsted in Grube 1859).

Flabelligera cariboea – Treadwell 1939: 280, 281, fig. 96 (non Grube & Ørsted in Grube 1859).

Semiodera cariboum – Hartman 1956: 294, 295 (non Grube & Ørsted in Grube 1859).

TYPE MATERIAL. — Southern Caribbean Sea. Holotype ( USNM 1156945 ) and 3 paratypes ( USNM 1156946 ), 5 km off S of Guayacancito, Isla Margarita, Venezuela, stn M42, in Thalassia , 13.II.1977, M. L. Jones (paratypes: 51-112 mm long, 3-8 mm wide, cephalic cage 4-6 mm long, 66-108 chaetigers; first neurohooks from chaetiger 6).

ADDITIONAL MATERIAL. — Northern Caribbean Sea. 2 specimens ( ECOSUR), 1 complete, regenerating the posterior end, and an anterior fragment, Punta Nizuc, Quintana Roo, Mexico, calcareous rock, 3 m, 31.VIII.1997, L. Carrera & M. A. Ruiz (complete previously dissected, 33 mm long, 4 mm wide, cephalic cage broken, 59 chaetigers).

Southern Caribbean Sea. 1 specimen ( UMML), regenerating the posterior end, University of Miami Deep Sea expeditions, R/ V Pillsbury, stn 428 (09°44’W, 79°22’W), off N Central Panama, 452 m, 20.VII.1966 (15 mm long, 2.5 mm wide, cephalic cage 4 mm long, 49 chaetigers; first neurohooks from chaetiger 6). — 1 specimen ( UMML), regenerating the posterior end, University of Miami Deep Sea expeditions, R/ V Pillsbury, stn 705 (10°45’N, 62°21’W), N Peninsula de Paria, Venezuela, 18 m, 18.VII.1968 (7.5 mm long, 1.5 mm wide, cephalic cage 5 mm long, 30 chaetigers; first neurohooks from chaetiger 6) .

TYPE LOCALITY. — Off S of Guayacancito, Isla Margarita, Venezuela, Caribbean Sea.

DISTRIBUTION. — Caribbean Sea, in sea-grasses ( Thalassia ), in shallow water.

ETYMOLOGY. — This species is named after my good friend and colleague Linda Ward, in recognition of her painstaking efforts to compile and update the polychaete bibliography, and especially for her friendship and warm support whenever I visit the USNM.

DESCRIPTION

Holotype complete, cylindrical, slightly tapering posteriorly ( Fig. 20A ), posterior region slightly damaged, 90 mm long, 7 mm wide, cephalic cage 6 mm long, 97 chaetigers. Tunic papillated, with fine sediment particles dorsally, extending ventrally over chaetigers 5-6 only ( Fig. 20B, C ); body wall grayish. Larger body papillae in longitudinal rows, dorsal ones barely visible, three per segment, four ventrally; ventral papillae tiny, without sediment.

Anterior end everted in holotype, slightly damaged ( Fig. 20B, C ), observed in paratypes. Cephalic hood short, margin smooth. Prostomium low, eyes large, black; caruncle well developed, separating the branchial plate in two halves, lateral ridges pale, medial keel darker, basally sinuous. Palps thin, short, palp bases low, rounded (two paratypes with exposed anterior end, slightly everting the anterior gut). Lateral lips thick, dorsal and ventral lips reduced. Branchiae cirriform, most lost, sessile filaments on a tongue-like protuberance, remaining filaments pale basally, dark medially, tips black; arranged in 6-9 longitudinal rows per side, with many filaments each ( Fig. 20F ). Basal branchiae shorter than palp. Nephridial lobes in external lateral base of branchial plate.

Cephalic cage chaetae as long as 1⁄₁₅ body length, or about as long as body width. Chaetigers 1-3 involved in the cephalic cage; first chaetiger displaced dorsally (left notochaetae removed); chaetae arranged in short series, each about the body corners. Chaetiger 1 with about 10 noto- and eight neurochaetae, thereafter about eight chaetae per bundle.

Anterior dorsal margin of first chaetiger papillated, partially damaged ( Fig. 20D ); chaetigers 1-4 without especially long papillae (some paratypes with epizoic hydrozoans). Chaetigers 1-3 of about the same length. Chaetal transition from cephalic cage to body chaetae abrupt. Chaetiger 5 with transitional short neurohooks; anchylosed falcate neurohooks from chaetiger 6. Gonopodial lobes not seen in holotype; some paratypes with a ventral transverse slit in chaetiger 5 (once the tunic is removed, a globular pale lobe underneath it; Fig. 20E ).

Parapodia better developed in chaetigers 1-4, posterior ones less developed, placed over the body corners. Median neuropodia ventrolateral. Notopodia short conical lobes with one short and a long postchaetal papillae, becoming longer in posterior chaetigers. Neuropodia flat, transverse lobe with two long papillae, one superior, another postchaetal. Noto- and neuropodia distant to each other.

Median notochaetae arranged in short transverse series, 5-6 per bundle, as long as 1⁄₅-1⁄₆ body width; all notochaetae multiarticulated capillaries, each with articles short basally, medium-sized medially, longer distally ( Fig. 20G ). Neurochaetae long, multiarticulated capillaries in chaetigers 1-4, chaetiger 4 with transition hooks ( Fig. 20H ), anchylosed neurohooks from chaetiger 5, arranged in J-patterns or oblique series, five hooks anteriorly, 6-7 medially, 4-5 posteriorly; each hook with short rings present to the median region, subdistally slightly expanded, with a discontinuous, oblique, dark spot, tip entire. Posterior end conical, without long papillae ( Fig. 20I ); pygidium with anus terminal, no anal cirri (one paratype regenerating its posterior end, anus with several radiating muscular lobes).

Variation

Complete paratypes had bodies fusiform or anteriorly swollen, without posterior end, or regenerating it (51-112 mm long, 3-8 mm wide, cephalic cage 4-6 mm long, 66-108 chaetigers). The relationship of cephalic cage chaetae length to body width (chaetiger 10) was mostly less than 1, with three specimens having a rate ≥ 1. Anchylosed neurohooks start in chaetigers 5-6. Gonopodial lobes were noticed by a short, ventral transverse slit, but once the tunic is removed, they can be seen as pale, rounded lobes. The number of notochaetae can be up to eight per bundle.

REMARKS

Trophoniella lindae n. sp. is closely allied to T. americana n. comb. from Galápagos and to T. tumbensis n. comb. from Chile because their tunics have sediment particles over the dorsal surface and might expand laterally. However, T. lindae n. sp. differs because it has small sediment particles, whereas the two other species have larger particles on their tunics. There has been much confusion regarding the recognition of this species because Ehlers (1887) described some specimens that he regarded as Siphonostomum cariboum Grube & Ørsted in Grube, 1859. However, Ehlers’ specimens do not belong in Semiodera because they do not have a dorsal shield, neither a very thin tunic, nor tiny papillae arranged in transverse rows.Consequently,it has been regarded appropriate to introduce a new name for this common, soft-bottom species, and to separate it from S. cariboum , which besides the above features, is a borer in calcareous substrates. Semiodera is revised elsewhere; it could be added that neurochaetae are also very different because they are shorter and fewer in this genus, whereas those present in Trophoniella are larger and more abundant.

Figures

FIG. 20. — Trophoniella lindae n. sp.: A, holotype (USNM 1156945), lateral view; B, same, anterior end, lateral view; C, same, anterior end, ventral view; D, paratype, without tunic, anterior end, dorsal view; E, same, anterior end, ventral view; F, another paratype, branchial plate, branchial filaments removed;G, another paratype,chaetiger 10,notochaetal basal,medial and distal regions;H, same, chaetiger 6, neurohooks (insert: neurochaetal tips, chaetiger 4); I, same, posterior end, lateral view. Scale bars: A, 7 mm; B, 1.7 mm; C, 2 mm; D, 1.3 mm; E, 1.4 mm; F, I, 0.9 mm; G, 90 µm; H, 150 µm.