Trophoniella chilensis ( Hartman, 1967 ) SALAzAR-Vallejo, 2012

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

Trophoniella chilensis ( Hartman, 1967) n. comb.

( Fig. 6 )

Therochaetella chilensis Hartman, 1967: 128 , 129, pl. 37, fig. C (not D) partim. — Rozbaczylo 1985: 161.

TYPE MATERIAL. — Chile. Holotype of Therochaetella chilensis ( USNM 55550) and 2 paratypes ( USNM 55551), R /V Eltanin, stn 753 (33°16’S, 71°47’W), 192 m, 26.IX.1963, with a ventral oblique dissection (paratypes of T. chilensis 2 anterior fragments and 2 median pieces; one is probably an undescribed species of Bradabyssa Hartman, 1967 but too damaged [see remarks]; anterior fragment 6 mm long, 1.6 mm wide, cephalic cage 4 mm long, 19 chaetigers).

DISTRIBUTION. — Only known from the type locality, off Santiago, Chile, in 192 m.

REDESCRIPTION

Holotype (USNM 55550) complete ( Fig.6A ).Tunic papillated, with many large sand particles dorsally ( Fig. 6B ) and ventrally, particles immersed in the tunic, without sediment particles along the posterior region.Body cylindrical, posteriorly tapered, 29 mm long, 2.5 mm wide, cephalic cage 6 mm long, 88 chaetigers (regenerating from chaetiger 71). Body papillae arranged in longitudinal rows; chaetigers 1-3 with slightly enlarged dorsal tubercles, posteriorly not significantly larger than other papillar lobes.

Anterior end not exposed in holotype; dissection not modified to avoid any further damage ( Fig. 6C ). Paratype with anterior end not exposed, but dissected. Prostomium low with two large circular, black eyes. Palps small. Branchiae cirriform, thick, about 42 pairs, placed over a short tongue-like plate. Nephridial lobes not seen.

Cephalic cage chaetae twice as long as body width. First three chaetigers involved in the cephalic cage; chaetae progressively smaller; 4-5 chaetae per bundle. Anterior dorsal margin of first chaetiger with a trilobed, small projection; anterior chaetigers with long, dorsolateral papillae (better preserved in paratype); posterior chaetigers with three rows of elongated papillae, each segment with three papillae, one middorsal and two dorsolateral. Chaetal transition from cephalic cage abrupt. Chaetal type changing in chaetiger 5, neurochaetae slightly thicker than notochaetae. Second neurochaetal type changing by chaetiger 25 (most chaetae broken, so it is difficult to be precise), anchylosed neurohooks thick. No gonopodial lobes; two ventral rows of single elongated papillae.

Parapodia better developed on first few chaetigers, posteriorly reduced. Noto- and neuropodia lateral. Notopodia with few long, postchaetal papillae, especially on anterior chaetigers. Up to three papillae per bundle, the median one the largest. Each papilla long, capitate.

Median notochaetae in short transverse series, six per bundle, as long as ½-⅔ body width; all notochaetae multiarticulated, basal articles short, long medially and distally ( Fig. 6D ). Median neuropodia ventrolateral; each with a postchaetal capitate papilla. Neurochaetae mostly bidentate, accessory tooth often eroded. Multiarticulate neurochaetae in chaetigers 1- c. 25; anchylosed neurohooks from around chaetiger 25; five multiarticulated capillaries in anterior neuropodia, 4-5 hooks in median and posterior neuropodia, arranged in transverse or slightly oblique series, each subdistally straight, with short articles continued to the subdistal region; tips bidentate ( Fig. 6E ), accessory tooth often eroded to small humps ( Fig. 6F ).

Posterior end in regeneration; pygidium without anal cirri; anus dorsoterminal.

REMARKS

Trophoniella chilensis n. comb. belongs to the group provided with anchylosed neurohooks in median chaetigers and a tunic with large sediment particles. It is unique because the particles are completely immersed in the tunic giving a smooth profile, whereas in the other species they are not completely covered by the tunic, giving a rough profile.

Trophoniella ehlersi ( Day, 1973) n. comb. ( Fig. 7 )

Pherusa sp. – McCloskey 1970: 26.

Pherusa ehlersi Day, 1973: 107 , 108, fig. 14g-j.

TYPE MATERIAL. — Northwestern Atlantic Ocean, eastern United States. Holotype ( USNM 43133 ), off Beaufort, North Carolina, Lookout outcrop, in corals, 18.3 m, 7.IX.1966, R. McCloskey (1 smaller specimen in the same vial belongs to the same species; 3.5 mm long, 0.7 mm wide, cephalic cage 2 mm long, 25 chaetigers).

ADDITIONAL MATERIAL.— Northwestern Atlantic Ocean, eastern United States. 1 complete specimen ( USNM 107986 ), off North Carolina, R/ V Onslow Bay, stn IS05 (32°24’06”N, 76°35’W), 18 m, 11.III.1981, identified by L. Wood (14 mm long, 3.5 mm wide, cephalic cage 3 mm long, 60 chaetigers; mature ♀, previously dissected ventrally, and with another longitudinal cut anterodorsally; anterior end missing; the latter was used to remove a portion of the dorsal outer cover and examine the surface of the anterior chaetigers). — 1 specimen ( USNM 107987 ), complete, off South Carolina, R/ V Bagby, stn IS01 (32°29’36”N, 79°42’30”W), 19 m, 21.I.1980, Roland & Knott id. (14 mm long, 4 mm wide, cephalic cage 3 mm long, 52 chaetigers; mature ♀, previously dissected throughout the anterior end; anterior end missing; parapodia removed to see chaetae). Gulf of Mexico. 1 specimen ( MCZ 1205 ), dried out, 400 m S off Sand Key, Florida, 18 m, 27.I.1868, L. F. de Pourtalès. — 1 specimen ( ECOSUR), Isla de Enmedio, Veracruz, Mexico, in sponge ( Ircinia strobilina ), 5 m, III.1992, L. Carrera (15 mm long, 2 mm wide, cephalic cage 4 mm long, 56 chaetigers). — 1 specimen (ECO- SUR), off Ria Lagartos , Yucatan, Mexico, 3 m, calcareous rock, 18.II.1999, R. Bastida & S. I. Salazar-Vallejo (16 mm long, 2.5 mm wide, cephalic cage 3 mm long, 49 chaetigers). — 1 specimen ( ECOSUR), juvenile, distorted, apparently regenerating the posterior end, off San Felipe , Yucatan, Mexico, 2 m, calcareous rock, 19.II.1999, S. I. Salazar-Vallejo (6 mm long, 1 mm wide, cephalic cage 3 mm long, 32 chaetigers) .

Caribbean Sea. 1 specimen ( ECOSUR), Punta Nizuc, Quintana Roo, calcareous rock, 3 m, 31.VIII.1997, L. Carrera (7 mm long, 1.5 mm wide, cephalic cage 3 mm long, 36 chaetigers). — 1 specimen ( ECOSUR), Punta Herradura, Quintana Roo, coral rock, 2 m, 28.X.1997, L. Carrera & S. I. Salazar-Vallejo (10 mm long, 2 mm wide, cephalic cage 3 mm long, 44 chaetigers; papillae tips pale). — 2 specimens ( ECOSUR), 1 complete and an anterior fragment, Buenavista , Xahuayxol , Quintana Roo, Mexico, coral rock, 1 m, 31.X.1997, L. Carrera & S. I. Salazar-Vallejo (complete 12 mm long, 3 mm wide, cephalic cage broken, 4 mm long, 57 chaetigers). — 1 specimen ( ECOSUR), Camping , Isla Contoy , Quintana Roo, Mexico, coral rock, 1 m, 22.II.1999, S. I. Salazar- Vallejo (18 mm long, 1.5 mm wide, cephalic cage 2 mm long, 49 chaetigers). — 1 specimen ( ECOSUR), Majagual , Quintana Roo, Mexico, coral rock, 1 m, XII.2000, P. Salazar (19 mm long, 2 mm wide, cephalic cage 4 mm long, 50 chaetigers). — 1 specimen ( ECOSUR), Punta Nizuc , Quintana Roo, Mexico, coral rock, 4 m, 10.II.2001, S. I. Salazar-Vallejo (14 mm long, 3 mm wide, cephalic cage 4 mm long, 52 chaetigers). — 2 specimens ( ECOSUR), 1 complete and an anterior fragment with head exposed, Rio Indio , Quintana Roo, coral rock, 17.III.2001, L. Carrera (complete 14 mm long, 2 mm wide, cephalic cage 3 mm long, 44 chaetigers). — 5 specimens ( ECOSUR), larger regenerating median and posterior regions, Xcacelito , Quintana Roo, Mexico, mixed bottom (rock and sand), 1 m, 26.X.2002, L. Carrera, P. Salazar & M. Londoño (11-24 mm long, 2.0-3.0 mm wide, cephalic cage 3-4 mm long, 44-57 chaetigers; papillae tips pale). — 3 specimens ( LACM-AHF 2482 ), Panama, Bocas delToro Archipelago , Laguna de Chiriqui, Isla Aqua (9.178°N, 82.054°W), northwest side, from chunks of Teredo-bored wood, among coral rubble and silty sand, 20-25 ft, SCUBA, 8.VIII.2003, W. Keel & L. Harris (5-13 mm long, 1 mm wide, cephalic cage 1.3 mm long, 38-44 chaetigers) .

DISTRIBUTION. — From the southeastern United States to the southwestern Caribbean Sea, in shallow water (1-20 m), mixed bottoms.

DESCRIPTION

Holotype (USNM 43133) cylindrical, blunt, slightly compressed anteriorly, tapering posteriorly ( Fig.7A ), 13 mm long, 1.8 mm wide, cephalic cage 3 mm long, 50 chaetigers (some parapodia previously removed). Tunic papillated, with fine sediment particles dorsally and ventrally.

Anterior end not exposed; not dissected to avoid further damage. Cephalic cage chaetae 1⁄₃ longer than body width. Chaetigers 1-3 involved in the cephalic cage. Chaetiger 4 with notochaetae long, more or less directed anteriorly but half as long as those in chaetiger 3. Cephalic cage chaetae arranged in a short series; each chaetiger with 3-4 chaetae, slightly more abundant ventrally.

Anterior dorsal margin of first chaetiger with a median, digitate papillae; anterior chaetigers with long, digitate, dorsolateral papillae in additional to notopodial ones.Chaetal transition from cephalic cage to body chaetae abrupt; chaetal change in chaetiger 4 with shorter notochaetae; anchylosed neurohooks from chaetiger 5. Gonopodial lobes not seen.

Parapodia poorly developed; chaetae emerging from the body wall. Noto- and neuropodia on body corners. Notopodia with two large digitate papillae per bundle, one on chaetal base, the other postchaetal.

Median notochaetae arranged in short transverse series, 3-4 per bundle, each as long as half body width; all notochaetae multiarticulated capillaries, articles short basally and medially, distally mediumsized ( Fig. 7B ). Median neuropodia ventrolateral. Neuropodia with digitate papillae, shorter than notopodial ones; one postchaetal papilla. Neurochaetae multiarticulated capillaries in chaetiger 4; from chaetiger 5, 4(-5) falcate hooks, tips entire; arranged in slightly oblique series, short rings present to the median region ( Fig. 7C ).

Posterior end a low cone; pygidium without anal cirri, but two dorsal, long papillae.

REMARKS

Trophoniella ehlersi n. comb. resembles T. grandis n. comb. because both species have fine sediment particles over the dorsal and ventral surfaces. They differ because in T. ehlersi n. comb. the anterior chaetigers do not have dorsal tubercles or notopodial lobes, whereas in T. grandis n. comb. there are dorsal tubercles in the first few chaetigers, and because in T. ehlersi n. comb. the falcate neurohooks start by chaetiger 5 whereas they start by chaetiger 7 in T. grandis n. comb.

McCloskey (1970) specimens were used for the original description; they were associated to a small tree-like scleractinian ( Oculina arbuscula Agassiz, 1864 ). The branching pattern of this coral allows some sedimentation on it; the polychaetes may have been found there, or in the sediment at the base of the coral. The finding of only four specimens by McCloskey, despite a very intensive sampling, precluded any ecological analysis on the species.

Figures

FIG. 6. — Trophoniella chilensis (Hartman, 1967) n. comb.: A, holotype (USNM 55550), dorsal view; B, same, anterior end, dorsal view; C, same, anterior end, ventral view; D, paratype (USNM 55551), chaetiger 17, basal, medial and distal notochaetal regions; E, same, chaetiger 19, neurochaetae (insert: largest chaetal tip); F, holotype,chaetiger 33,neurochaetae (insert: largest chaetal tip). Scale bars: A, 1.2 mm; B, 0.5 mm; C, 0.4 mm; D, 112 µm; E, 70 µm; F, 150 µm.

FIG. 7. — Trophoniella ehlersi (Day, 1973) n. comb.: A, holotype (USNM 43133), dorsal view; B, same, chaetiger 10, notochaetal basal, median and distal regions; C, non-type specimen (USNM 107987), chaetiger 44, neurochaetae. Scale bars: A, 2.25 mm; B, 60 µm; C, 45 µm.