Trophoniella rudis (SALAzAR-Vallejo, 2012)

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

Trophoniella rudis

(Grube & Müller in Grube, 1877) n. comb. ( Fig. 25 )

Stylarioides rudis Grube & Müller in Grube, 1877: 67, 71 (diagnosis). — Hartwich 1993: 134 partim.

Siphonostomum cariboum – Treadwell 1901: 208 partim (non Grube & Ørsted in Grube 1859).

Piromis sp. ? – Nonato & Luna 1970: 90, 91, fig. 78.

TYPE MATERIAL. — Southwestern Atlantic Ocean. 3 syntypes of Stylarioides rudis ( ZMB Q4791), off Florianopolis (olim Desterro), Santa Catharina Island, Brazil, F. Müller, 1 slide made from the former ( ZMB 69146-01(5)), with some bubbles, contains few noto- and neurochaetae.

ADDITIONAL MATERIAL. — Southwestern Atlantic Ocean. 1 specimen ( MNHN A183) slightly damaged, Abrolhos Archipelago (17°45’S, 38°50’W), 20 m, 1883, M. Parfait (16 mm long, 2.5 mm wide, cephalic cage 6 mm long, broken, 60 chaetigers). Gulf of Mexico. 1 specimen ( USNM 1156948), breaking in 2, off Pepperfish Key, Florida, R/V Fish Hawk, stn 7151, 5.5 fathoms, 7.XI.1901 (12 mm long, 2 mm wide, cephalic cage 4 mm long, 45 chaetigers).

Caribbean Sea. 1 specimen (LACM-AHF 2500), pale, Allan Hancock Atlantic expedition, stn A14 (12°11’55”N, 72°11’03”W → 12°11’20”N, 72°11’16”W), 2 miles SW Cape La Vela, Peninsula La Guajira, Colombia, 22-21 fathoms, gray sand, 8.IV.1939 (17 mm long, 2 mm wide, cephalic cage 4 mm long, 51 chaetigers). — 1 specimen (USNM 16164), broken in 2, Ensenada Honda, Culebra, Puerto Rico, during the U.S. Fish Commission Porto Rico expedition, 1898-99, R/V Fish Hawk, 11.II.1899 (17 [8 + 9] mm long, 3 mm wide, cephalic cage 2 mm long, 51 [28 + 23] chaetigers).

DISTRIBUTION. — Originally described from Florianopolis (27°30’S, 48°30’W), formerly called Desterro, Santa Catharina Island, Brazil, where most Müller’s specimens came from, but there are no more data. The specimen studied by Nonato & Luna (1970), which seems to be conspecific, comes from northeastern Brazil (off NE Maceió, Alagôas, c. 40 m, in calcareous algae). The specimen from Florida, together with the other ones found in Puerto Rico and Colombia, extend the distribution into the Great Caribbean region.

DESCRIPTION

Syntypes one complete specimen ( Fig. 25A ), an anterior fragment ( Fig. 25E ; measurements in parenthesis below), and a non-matching posterior fragment (probably dissected by Grube to observe the anterior end). Body fusiform, tapering posteriorly, complete syntype 29 mm long, 5 (4) mm wide, cephalic cage 5 (7) mm long, 54 (29) chaetigers. Tunic mostly without sediment particles, some sand grains on anterior fragment ( Fig. 25E ); body wall solid brown. Body papillae abundant, most thin, small, fragile, digitate, leaving rounded, low scars on tunic, giving a very rugose profile; larger papillae fewer, cylindrical or clavate, fragile, placed along chaetal lobes and arranged in longitudinal rows (two dorsal, one lateral and four ventral ones).

Cephalic hood not exposed; anterior fragment with palps exposed; not dissected to avoid further damage.

Cephalic cage chaetae as long as ¼-1⁄₆ body length, as long as, or longer than body width. Chaetigers 1-4 involved in the cephalic cage, chaetae arranged in short dorsolateral series, with about 7-8 noto- and 4-5 neurochaetae. Anterior dorsal margin of first chaetiger with a median trifid lobe, projected anteriorly ( Fig. 25B, D ). Anterior chaetigers with long papillae. Chaetigers 1-3 of about the same length. Chaetal transition from cephalic cage to body chaetae abrupt, falcate anchylosed neurohooks start in chaetiger 5. Gonopodial lobes present in chaetiger 5, broken from the base, scar remains.

Parapodia lateral, poorly developed; chaetae emerge from the body wall. Median neuropodia ventrolateral. Noto- and neuropodia not forming long lobes; anterior parapodia with abundant long papillae. Median notopodia with 2-4 infrachaetal smaller papillae and 3-5 larger papillae ( Fig. 25F ). Neuropodia with 1-2 infrachaetal and 3-4 suprachaetal papillae.

Median notochaetae arranged in short transverse series, 7-8 notochaetae per bundle, about as long as 1⁄₅ body width; all notochaetae multiarticulated capillaries, each with articles short basally, long medially and distally ( Fig. 25F , insert). Neurochaetae multiarticulated capillaries in chaetigers 1-4, all articles short, in chaetiger 4 with falcate tip. Falcate anchylosed, darker neurohooks from chaetiger 5, feebly developed rings continued to about half the exposed part ( Fig. 25G ); neurohooks arranged in transverse series, or as an inverted J-pattern, 5-6 in anterior and posterior chaetigers, 6-7 in median chaetigers, each with short rings extending almost to the distal part, subdistally straight, tip falcate, entire.

Posterior end tapering to a blunt rounded tip ( Fig. 25C ); pygidium with anus terminal, with many long papillae; no anal cirri.

REMARKS

Trophoniella rudis n. comb. is closely allied to T. reishi n. sp. as both have an early start of anchylosed, unidentate neurohooks, and because their tunic has very few sediment particles, being apparently without any sediment particles. They differ by the relative basic body wall pigmentation and the cephalic cage length. Thus, in T. rudis n. comb., the body is solid brown, and the cephalic cage chaetae are 1.0-1.5 times longer than body width, whereas in T. reishi n. sp. the body is dark pink, with fine red spots or rarely pale, and the cephalic cage is twice as long as body width.

The short note by Müller (1858: 218) indicates that he saw living specimens and although he commented that the “upper tentacles” were branchiae, he does not provide any other morphological details.The main diagnostic features for Trophoniella rudis n. comb. were: body with 60-74 chaetigers; papillae in two longitudinal rows dorsally and ventrally, one lateral row with longer, thinner papillae; cephalic cage made by chaetigers 1-4; neuropodia with four hooks per bundle; and branchiae cirriform, 24 filaments in a branchial plate distally notched. This series of characters resembles Piromis sp. as recorded by Nonato & Luna (1970); they stated that their specimen had gonopodial lobes in chaetiger 5, which were not included in the original diagnosis, but are visible in the largest syntype. The anterior end features could not be confirmed because of the state of the specimens; further, the discrepancy on the number of neurohooks may be explained by the then available microscopes, or because only the larger ones were seen or counted.

Figures

FIG. 25. — Trophoniella rudis (Grube & Müller in Grube, 1877) n. comb.: A, complete syntype (ZMB Q4791), lateral view; B, same, anterior end, dorsal view; C, same, posterior end, lateral view; D, same, anterior end, ventral view (GL, gonopodial lobes, broken); E, another syntype, anterior end, dorsal view; F, same, chaetiger 12, notopodium and basal, medial and distal notochaetal regions; G, same, chaetiger 29, neurochaetae. Scale bars: A, 2 mm; B, 1.35 mm; C, 0.7 mm; D, 1 mm; E, 0.8 mm; F, 225 µm; G, 73 µm.