Trophoniella fernandensis ( Augener, 1918 )

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

Trophoniella fernandensis ( Augener, 1918) reinstated, n. comb.

( Fig. 11 )

Pycnoderma fernandense Augener, 1918: 448-451 , pl. 6, figs 148, 182, pl. 7, figs 237, 238, textfig. 67.

Flabelligera affinis – Fauvel & Rullier 1959: 180 (non Sars 1829).

Piromis arenosus – Fauvel & Rullier 1959: 181. — Intes & Le Loeuff 1977: 236 (non Kinberg 1867).

MATERIAL EXAMINED. — Mediterranean Sea. Anterior fragment ( IRFA), off Rovigno d’Istria , Croatia, stn 314 (no further data), 1966, Vatova (18 mm long, 2.3 mm wide, cephalic cage chaetae broken, 34 chaetigers). — 1 specimen ( SMF 14849), baie du Lazaret, Toulon, France, 1.VI.1982, V. Díaz-Castañeda (23.5 mm long, 1.5 mm wide, cephalic cage 1.5 mm long, 59 chaetigers; regenerating the dorsal body wall of first few chaetigers; first anchylosed neurohooks by chaetiger 32) ; 1 specimen and 3 fragments ( SMF 14904), same data, but 28.VI.1982 (complete 9.0 mm long, 1.0 mm wide, cephalic cage 1.0 mm long, 49 chaetigers) ; 1 mature ♀ ( SMF 14937), broken in 2, many chaetae broken, same data, but 11.III.1983 (20 mm long, 1.8 mm wide, cephalic cage 2 mm long, 56 chaetigers; oocytes about 100 µm) ; 1 specimen ( SMF 14993), same data, but 12.X.1982 (used for redescription) ; 2 specimens ( SMF 15124) damaged, many chaetae broken, same data, but 15.XI.1982 (11.8 - 20.0 mm long, 1 - 2 mm wide, cephalic cage 0 - 2 mm long, 39 - 52 chaetigers) ; anterior fragment ( SMF 15054), damaged, most chaetae broken, same data, but 11.III.1983 (17 mm long, 1.0 mm wide, cephalic cage broken, 39 chaetigers) ; 2 fragments ( SMF 15136), same data, but 15.XI.1982. — Anterior fragment ( USNM 1156916 ), collected off île de Ryon, S of Marseille , France, dredged, 60-80 m, 1969-1970, M. Pichon (24 mm long, 2.5 mm wide, cephalic cage chaetae 2 mm long, 45 chaetigers) .

Eastern tropical Atlantic. Anterior fragment ( MNHN A383), off Conakry, Guinea, R/V Calypso , stn 7 (09°40’N, 14°05’W), 18 m, 17.V.1956 (apparently complete, tapered anteriorly, 20 mm long, 2 mm wide, cephalic cage chaetae 2 mm, 37 chaetigers). — Anterior fragment ( MNHN A383), off Sekondi-Takoradi, Ghana, R/V Calypso , stn 26 (04°37’N, 00°50’W), 90-100 m, 24.V.1956 (without posterior region; red-yellowish, tapered anteriorly, 21 mm long, 2 mm wide, cephalic cage chaetae 2 mm, 45 chaetigers).

Red Sea. Anterior fragment ( BMNH 1955.10.12.49), complete, with an anterodorsal dissection and a lateral distortion due to pressure, off Arlit (31°41’14”N, 34°56’18”E), Israel, dredged, 36 m, 2.XII.1948, A. Yashouv (12.5 mm long, 1.8 mm wide, cephalic cage 1.5 mm long, 34 chaetigers; median chaetigers with 13 - 15 transverse rows of papillae) .

DISTRIBUTION. — Originally described from equatorial western Africa, it apparently ranges northwards into the Mediterranean and probably into the Red Sea, in soft bottoms in 25-70 m depth. This distribution might include more than one species, but they have been retained as a single one because of the preservation condition of the materials. There seems to be differences in the relative size of articles in notochaetae, being shorter in western African specimens and medium-sized or long in Mediterranean ones, but to separate them as distinct species requires better specimens.

ETYMOLOGY. — The original epithet spelling, “fernandense”, might have tried to indicate one of the collecting sites ( Fernando Póo Island, Guinea), adjusted to the apparent feminine gender of Pycnoderma Grube, 1877 . The suffix has been corrected to - ensis, as a means to indicate that the species thrives in that locality.

DESCRIPTION

Complete specimen (SMF 14993), most chaetae broken, some papillae eroded ( Fig. 11A ). Body subcylindrical, truncate anteriorly, tapering posteriorly; body colour concentrated in papillae; reddish anteriorly, fading to orange medially, pale posteriorly, 32 mm long, 2.5 mm wide, cephalic cage chaetae broken, 2 mm long, 63 chaetigers. Tunic thin, without sediment particles, softer in posterior chaetigers, not forming a crust. Papillae small, dorsal papillae slightly larger than ventral ones, each with fine brown-reddish sediment forming brown spherules, arranged in about 15 transverse rows in median segments.

Anterior end observed in two other specimens (MNHN A383, SMF 14937; Fig.11E ). Prostomium low cone; eyes dark brown, medium-sized.Caruncle long, separating the branchial plate in two lateral groups, not reaching the posterior margin. Palps long, pale; palp keels rounded, elevated. Lateral, ventral and dorsal lips apparently fused, forming a projected cone. Branchiae thin, cirriform, motled with irregular brown bands or colourless; sessile on a tongue-like protuberance, separated in two lateral groups; each group with branchiae arranged in four concentric rows, longest row with up to 20 filaments, about 60 filaments per group. Largest branchiae thinner and as long as palps. Nephridial lobes not seen.

Cephalic cage made by chaetiger 1 ( Fig. 11B, C ), chaetae less than 1/15 body length or slightly shorter than body width; each chaeta thin, about 2 mm long (slightly less than body width at chaetiger 10); 4-5 chaetae per bundle. Chaetal transition abrupt, chaetiger 2 with shorter notochaetae (1 mm long) and bifid neurochaetae. First chaetigers without dorsal lobes nor larger middorsal papillae. Dorsal margin of chaetiger 1 papillated. Ventral surface without ventrolateral lappets or gonopodial lobes.

Noto- and neuropodia lateral, both scarcely developed ( Fig. 11F ); associated papillae not markedly longer than other dorsal ones.

Median notochaetae arranged in longitudinal or oblique series, 4-5 notochaetae anteriorly, 5-7 posteriorly, as long as ½ body width; all notochaetae multiarticulated capillaries with long articles throughout the chaeta ( Fig. 11F , inserts), shorter in other specimens. Neuropodia scarcely developed; associated papillae not markedly longer than the dorsal ones; 3-4 bidentate hooks anteriorly, 2-3 posteriorly. Bidentate neurohooks starting from chaetiger 2 (IRFA; in other specimens mostly broken), with short articles basally, longer ones medially and distally, continued to posterior chaetigers; from about chaetiger 45 anchylosed neurohooks, continued to the posterior end, bidentate, medially expanded, with short rings basally, fang curved, accessory tooth laminar, subdistally markedly expanded, fragile, often reduced to a thin, triangular blade ( Fig. 11G , inserts).

Posterior end slightly swollen, without achaetous segments ( Fig. 11D ); pygidium rounded, anus terminal, without anal cirri.

REMARKS

Trophoniella fernandensis n. comb. resembles T. fiegei n. sp. but they differ in the tunic surface, number of transverse rows of papillae and the start of anchylosed neurohooks. In T. fernandensis n. comb. the tunic is velvety or rugose, whereas it is smooth in T. fiegei n. sp.; there are 15 transverse rows of papillae in T. fernandensis n. comb. whereas there are only 6-9 in T. fiegei n. sp., and in T. fernandensis n. comb. anchylosed neurohooks start by chaetiger 45 whereas they start by chaetiger 50 in T. fiegei n. sp.

Another species, Pycnoderma glabra ( Treadwell, 1901) , is regretfully too poorly known and has been included in that genus because there were no posterior chaetae (Salazar-Vallejo 2011a: 38), but that transfer might be modified once more and better specimens will be available. In case they belong to the same genus, their body papillae are homogeneously short and not adhering large sediment grains. These two species might be similar and besides the type of posterior neurochaetae, the only apparent differences are the amount of transverse rows of papillae in median chaetigers and the formation of a crust in posterior chaetigers; thus, in T. fernandensis n. comb., median chaetigers have about 15 transverse rows per segment and its tunic does not form a crust, whereas in P. glabra there are only about 10 transverse rows per segment and its tunic makes a crust in posterior chaetigers. This difference, however, requires more specimens of the latter species to better define its diagnostic features and its generic placement.

As originally stated by Augener (1918: 451, 452), his species is more closely allied to other species formerly belonging in Piromis , rather than in Pycnoderma ; he may have assigned his species to that genus because it lacks any large sediment particle adhered to the outer cover, just as it happens in the then only known species, P. congoense Grube, 1877 . However, it shares chaetal features with Trophoniella , especially by the presence of anchylosed neurohooks in the posterior fourth of the body, which were even detailed in the original description, hence the new combination.

Figures

FIG. 11. — Trophoniella fernandensis (Augener, 1918) reinstated,n. comb.: A, complete specimen (SMF 14993), lateral view; B, same, anterior end,dorsal view;C, same, anterior end, lateral view;D, same,posterior region,lateral view;E, another specimen (SMF 14937), head,frontal view,palps and most branchiae detached;F, previous specimen (SMF 14993),chaetiger 9 complete (inserts:basal,medial and distal notochaetal regions and neurochaetal tip); G, same, chaetiger 56, neurochaetae (inserts: neurochaetal tips). Scale bars: A, 2 mm; B, 0.85 mm; C, 1.5 mm; D, 0.4 mm; E, 0.2 mm; F, 210 µm; G, 90 µm.