Piromis robertsi ( Hartman, 1951 )

Salazar-Vallejo, Sergio I., 2011, Revision of Piromis Kinberg, 1867 and Pycnoderma Grube, 1877 (Polychaeta: Flabelligeridae), Zootaxa 2819, pp. 1-50 : 21-23

Piromis robertsi ( Hartman, 1951)

Figure 8

Semiodera roberti Hartman, 1951:99 , Pl 26, Figs. 1–4 .

Piromis roberti: Hartman, 1961: 123 n. comb.; Fauchald, 1972: 416 n. comb.; Milligan, 1984:47.5–47.7, Figs. 47.1–2.

Type material. Gulf of Mexico. Holotype (LACM-AHF -526), Grand Terre (29°16ʹ54ʺ N, 89°55ʹ45ʺ W), Sugar House Bend, Louisiana, 25 Jun. 1942, J.H. Roberts, coll.

Additional material. Gulf of Mexico. Anterior fragment ( USNM 45650), previously dissected and first two chaetigers separated from the rest of the body, together with three anterior fragments of P. w e b s t e r i, Tampa Bay, Florida, 1963, J.L. Taylor, coll. (first neurohooks apparently from chaetiger 7). Anterior fragment ( USNM 55986), damaged, R/V Columbus Iselin, Sta. 2528 (29°54ʹ58.6ʺ N, 86°04ʹ58.5ʺ W), 37 m. Anterior fragment ( USNM 74837) apparently fixed with alcohol, Sta. number not specified (30°20ʹ N, 88°47ʹ W) (first chaetiger with a trifid structure on its anterior margin). Anterior fragment ( USNM 75920), R/V Captain Brady Joseph, Sta. M10-2 (29°39ʹ52ʺ N, 93°28ʹ34ʺ W), 9.8 m, Apr. 1982, G.R. Gaston, coll. (first neurohooks in chaetiger 5; second chaetiger with two ventral tubercles). Anterior fragment ( USNM 75921), R/V Captain Brady Joseph, Sta. M10-2 (29°39ʹ52ʺ N, 93°28ʹ34ʺ W), 9.8 m, Apr. 1982, G.R. Gaston, coll. (first neurohooks in chaetiger 5; second chaetiger with two ventral tubercles). Two juveniles ( USNM 75922), one complete, R/V Captain Brady Joseph, Sta. M10A-6 (29°39ʹ52ʺ N, 93°28ʹ34ʺ W), off Cameron, Louisiana, 9.8 m, Sep. 1982, G.R. Gaston, coll. (first neurohooks from chaetiger 5). A juvenile ( USNM 75925), broken in two, R/V Captain Brady Joseph, Sta. M10A-6 (29°40ʹ0 9ʺ N, 93°28ʹ12ʺ W), off Cameron, Louisiana, 9.4 m, Aug. 1981, G.R. Gaston, coll. (first neurohooks from chaetiger 5). One specimen ( USNM 754456), Sta. 27 (30°18ʹ17ʺ N, 88°43ʹ0 4ʺ W), 2.6 m, 23 Oct. 1980 (tunic very thin with fine sediment grains; chaetiger 3 with thin bifid hooks, become thicker by chaetiger 4).

Description. Holotype damaged, most chaetae broken, cylindrical, compressed because of inadequate preservation ( Fig. 8 A); tunic papillated, with large sediment particles adhered, especially dorsally ( Fig. 8 B, D); papillae in two longitudinal rows dorsally, four rows ventrally, mostly eroded ( Fig. 8 C); each papilla cirriform, capitate. Holotype 58 mm long, 2.5 mm wide, cephalic cage 3.5 mm long, 107 chaetigers.

Anterior end damaged, everted, some portions already eroded. Cephalic hood short, margin unknown. Prostomium elevated; four eyes, fused, directed fronto- and posterolaterally. Caruncle well developed, separating branchial lobes. Palps lost, palp keels rounded, short. Branchiae cirriform, arising on tongue-like protuberance, about 60 filaments per side. Size relationships with palps or among themselves unknown. Nephridial lobes not seen.

Cephalic cage present, chaetae about 1/15 body length, or slightly longer than body width. Chaetigers 1–2 involved in cephalic cage; chaetae arranged in short rows, lateral and ventrolateral fascicles; each with 3–4 notochaetae and 2–3 neurochaetae per bundle. Anterior dorsal margin of first chaetiger with a median trifid lobe, projected anteriorly; anterior chaetigers with long papillae, chaetigers 2–3 with notopodial lobes. Chaetigers 1–3 of similar length. Chaetal transition from cephalic cage to body chaetae abrupt; chaetiger 4 with thick, bifid neurohooks (in one topotype). Gonopodial lobes not seen.

Parapodia lateral, well developed, especially in anterior chaetigers; median neuropodia ventrolateral ( Fig. 8 D). Notopodia with one pre- and three postchaetal papillae, each cirriform, capitate. Neuropodia with one pre- and two postchaetal papillae, smaller than notopodial ones.

Median notochaetae arranged in a short transverse row, 7–8 notochaetae per bundle, about as long as 1/3 body width; all notochaetae multiarticulated capillaries ( Fig. 8 E), basal and medial articles short, become longer distally. Neurochaetae multiarticulated capillaries in chaetigers 1–2, chaetiger 3 with a multiarticulated capillary with hooked tip, entire, from chaetiger 4 all neurochaetae bifid hooks, arranged in a transverse row, 7–8 hooks per ramus, continued to last chaetigers, many hooks broken, articulations shorter in anterior and median chaetigers ( Fig. 8 F), shorter in posterior chaetigers ( Fig. 8 G). Posterior neurohooks with 3–5 long articles; distal piece slightly falcate, tapering, bidentate.

Posterior region tapering slightly; pygidium with dorsal anus, exposed muscular ring, without anal cirri.

Remarks. Piromis robertsi ( Hartman, 1951) resembles P. fauchaldi n. sp. from the Gulf of California, because both species have large sediment particles on the tunic. They differ in three features: the number of notochaetae, presence of ventrolateral tubercles in chaetiger 1, and in the number of articles per neurohook in posterior chaetigers. Thus, while P. robertsi has up to eight notochaetae per bundle, there are only five in P. fauchaldi n. sp.; P. robertsi has ventrolateral tubercles which are missing in P. fauchaldi n. sp., where a group of papillae take the same position but not fused to form a tubercle. Finally, there are fewer articles per posterior neurohook in P. robertsi (3– 7), while there are almost twice as many in P. fauchaldi (10–12).

The name of the species should be changed since it was named after Mr. J.H. Roberts, the collector of the type material; the name is therefore emended to be spelled robertsi ( ICZN 1999, Art. 33.2.1).

Distribution. Northern Gulf of Mexico, in shallow water.

Figures

FIGURE 1. Piromis arenosus Kinberg, 1867. A. Syntypes in lateral view. B. Thicker syntype, anterior end, dorsal view. C. Same, posterior end, lateral view. D. Non-type specimen (LAMNH- 5210), anterior end dissected, slightly collapsed, palps and most branchiae removed (BS: branchial scars, Ca: caruncle, DL: dorsal lip, LL: lateral lip, Pr: prostomium, PS: palp scar). E. Thicker syntype, notochaetae portions, basal, medial and distal with an insert of the tip. F. Non-type specimen (LAMNH-AHF- 2506), neurochaetae from a median chaetiger with an insert of one tip. G. Same, neurochaetae from a posterior chaetiger with an insert of a tip. Scale bars: A: 6 mm, B: 1.5 mm, C – D: 1 mm, E: 25 µm, F: 90 µm, G: 40 µm.

FIGURE 2. Piromis amoureuxi n. sp. A. Holotype (MNHN- 900), twisted. B. Same, anterior end in dorsal view. C. Same, median segments in lateral view, showing sediment particles dorsally and laterally. D. Paratype (MNHN- 900 a), anterior end, palps and most branchiae detached (BD: branchial scars, LL: lateral lip, PS: palp scar). E. Holotype, anterior notopodium. F. Same, close-up of notochaetal regions, left, median and distal. G. Same, neurochaetae from a median chaetiger. H. Same, neurochaetae from a posterior chaetiger. Scale bars: A: 1 mm, B – C: 0.5 mm, D: 0.3 mm, E: 100 µm, F: 10 µm, G: 50 µm, H: 25 µm.

FIGURE 3. Piromis brisegnoi n. sp. A. Holotype (LAMNH-AHF- 2509), lateral view. B. Same, anterior end, lateral view showing abundant chaetae and long papillae. C. Non-type specimen, anterior end, frontal view, palps and branchiae removed (BS: branchial scars, LL: lateral lip, PS: palp scar, VV: ventral lip). D. Holotype, notochaetae from an anterior chaetiger. E. Same, neurochaetae from a median chaetiger, insert showing the tips. F. Same, neurochaetae from a posterior chaetiger, insert showing the tip. Scale bars: A: 5 mm, B: 1.5 mm, C: 0.5 mm, D: 150 µm, E: 60 µm, F: 50 µm.

FIGURE 4. Piromis capulata (Moore, 1909) n. comb. A. Holotype (CAS- 19721), complete in lateral view. B. Same, anterior end, lateral view. C. Same, anterior end, dorsal view, notice the eroded areas. D. Non-type specimen (USNM- 40484), anterior end, dorsal view. E. Same, anterior end, palps and most branchiae detached (BS: branchial scars, LL: lateral lip). F. Same, right neuropodium showing the gonopodial lobe with an asterisk in the base. G. Holotype, notochaetal regions, basal, median, distal. H. Same, median neuropodia with an insert showing the tips. Scale bars: A: 5 mm, B: 2.3 mm, C: 1.5 mm, D – E: 2 mm, F: 325 µm, G: 100 µm, H: 50 µm.

FIGURE 8. Piromis robertsi (Hartman, 1951). A. Holotype (LAMNH- 526), complete, lateral view. B. Same, anterior end, dorsal view. C. Same, anterior end, ventral view. D. Non-type specimen (USNM- 75920), parapodium from chaetiger 9. E. Holotype, details of notochaeta from chaetiger 75. F. Non-type specimen, neurochaetae from chaetiger 9. G. Holotype, neurochaetae from chaetiger 67. Scale bars: A: 4 mm, B – C: 0.5 mm, D: 0.45 mm, E: 506 µm, F: 120 µm, G: 72 µm.