Piromis websteri Day, 1973

Salazar-Vallejo, Sergio I., 2011, Revision of Piromis Kinberg, 1867 and Pycnoderma Grube, 1877 (Polychaeta: Flabelligeridae), Zootaxa 2819, pp. 1-50 : 26-28

Piromis websteri Day, 1973 status novo

Figure 11

Trophonia arenosa Webster, 1879:245 –246, Pl. 7, Figs. 92–97. Piromis eruca websteri Day, 1973:109 , no figs.

Type material. Northwestern Atlantic Ocean. Syntypes ( USNM 433), H.E. Webster coll., id., Virginia, no further data (two almost complete specimens lacking posterior end, anterior end dissected; there might have been a third specimen since one of the original illustrations indicates a cross section of a median chaetiger; most chaetae broken, sediment cover removed from many areas. Longer syntype 43 mm long, 5 mm wide, 63 chaetigers.

Additional material. Virginia: Anterior fragment ( USNM 57058), slightly damaged, Chincoteague, Chesapeake Bay, 12 Aug. 1965, in eelgrass (dorsal lobes in chaetigers 2–6). Two specimens (VIMS-535), Eelgrass bed, Chincoteague, 12 Aug. 1965, M.L. Wass, coll. (both with neurospines in chaetiger 6). North Carolina: Two specimens ( USNM 53880), one complete with swollen posterior end, Banks Channel, Wrightsville Beach, North Carolina, intertidal, muddy sand, no date, T. Fox, coll. (first neurohooks in chaetiger 6; second chaetiger with two ventral tubercles). One specimen ( USNM 53881), Banks Channel, Wrightsville Beach, North Carolina, intertidal, shelly mud, 27 Jul. 1973, C. Jenner, coll. (first neurohooks in chaetiger 6; second chaetiger with two ventral tubercles). One specimen ( USNM 53883), without posterior end, Banks Channel, Wrightsville Beach, North Carolina, sandy mud, 8 Mar. 1974, C. Jenner, coll. (first neurohooks in chaetiger 6; second chaetiger with two ventral tubercles). One specimen ( USNM 53884), without posterior end, Banks Channel, Wrightsville Beach, North Carolina, soft mud, 2 Nov. 1974, C. Jenner, coll. (first neurohooks in chaetiger 6; second chaetiger with two ventral tubercles). One specimen ( USNM 53885), from muddy sand, Bogue Sound, Morehead City, 23 June 1975, S.L. Gardiner, coll. One specimen ( USNM 61742) from Middle Marsh, soft mud, 23 Jul. 1976. Gulf of Mexico: One specimen (UMML-unnumbered), Rookery Bay (26°01ʹ30ʺ N, 81°44ʹ40ʺ W), 32.1.7, no further data. Three anterior fragments ( USNM 45650), together with an anterior fragment of P. robertsi, Tampa Bay , Florida, 1963, J.L. Taylor, coll. (all with neurohooks from chaetiger 6). One specimen ( USNM 71158), 3 mi SE off Dauphin Island (30°11ʹ17ʺ N, 88°07ʹ17ʺ W), 18 Sep. 1981, 42 feet, S.L. Gardiner id. Three specimens ( USNM 61742), one complete, “Middle Marshʺ, North Carolina, 23 Jul. 1976, soft mud, S.L. Gardiner, coll. (dorsal, paired tubercles in chaetigers 2–6). One specimen ( USNM 75920), anterior fragment, damaged, R/V Captain Brady Joseph, Sta. M10-2 (29°39ʹ52ʺ N, 93°28ʹ34ʺ W), off Cameron, Louisiana, 9.8 m, Feb. 1982, G.R. Gaston, coll. (hooks start apparently in chaetiger 6). One specimen ( USNM 75921), anterior fragment, R/V Captain Brady Joseph, Sta. M10-2 (29°39ʹ52ʺ N, 93°28ʹ34ʺ W), off Cameron, Louisiana, 9.8 m, Apr. 1982, G.R. Gaston, coll. (hooks start in chaetiger 6). One specimen ( USNM 75923), R/V Captain Brady Joseph, Sta. 10-6(29°39ʹ52ʺ N, 93°28ʹ34’ W), 9.8 m, May 1982, G.R. Gaston, coll.

Redescription. Smaller syntype tapering posteriorly, oval in cross section, sediment cover removed in many areas, remaining as a thin layer of sand grains with clear, eroded areas dorsally and laterally ( Fig. 11 A), sediment cover better conserved in other specimens ( Fig. 11 B). Anterior end with five chaetigers directed anteriorly. Syntype 28 mm long, 3 mm wide, cephalic cage 4 mm long, 58 chaetigers (with a longitudinal dissection, ventrally along chaetigers 45–52).

Cephalic hood not exposed, anterior end retracted (original dissection by Day; other specimens with everted anterior end show a short cephalic hood, as long as chaetiger 1 length). Anterior end details based on non-type materials ( Fig. 11 C; VIMS-535). Prostomium low; eyes large, slightly pigmented. Caruncle with diffuse pigmentation. Another specimen (USNM 53883), with anterior end everted; prostomium low; eyes large, fused. Caruncle with median keel pale, lateral ridges basally pigmented.

Cephalic hood short, margin entire, not crenulated or papillated. Palps long, corrugated, with black spots; palp keels low (larger specimens with pigmented. swollen palp keels). Mouth with two thick lateral lips, dorsal lip reduced, ventral lip thin; buccal organ exposed. Branchiae cirriform, placed on a tongue-shaped lobe, separated in two lateral groups, each with about 60 branchial filaments. Size relationship with palps not discernible. Nephridial lobes not seen.

Cephalic cage chaetae slightly longer than body width; cephalic cage made by the first three chaetigers, but longest chaetae in chaetigers 1–2; chaetae arranged in a tuft. Notopodia 1–2 with 2–3 chaetae, neuropodia 1–2 with 3–4 chaetae.

Anterior dorsal margin of chaetiger 1 with a median projection, distally eroded; chaetigers 2–3 with pair of dorsolateral elongated papillae, and single long notopodial papilla. Dorsal tubercles eroded in syntypes, present in non-type specimens from North Carolina. Post-cephalic cage chaetigers not elongated. Chaetal transition from cephalic cage to body chaetae abrupt; chaetiger 4 with short notochaetae, bifid neurohooks replacing capillaries (after Webster and Day; no chaetae left, but confirmed in the additional materials). Chaetiger 1 with two ventrolateral lobes, branched, on its anterior margin, better preserved in some specimens ( Fig. 11 B, USNM 53883). Gonopodial lobes not seen.

Anterior parapodia projecting more than median or posterior ones; those as lower chaetal lobes. Parapodia placed over the body corners in cross section, at about the same distance to each other. Notopodia with long pre- and postchaetal papillae, the latter longer, especially on chaetigers 1–4.

Median notochaetae in transverse row, with about six chaetae per bundle (up to 11 in larger specimens), reduced to 5 (7 in larger specimens) in posterior chaetigers, about 1/3 as long as body width; all notochaetae multiarticulated capillaries ( Fig. 11 D) with short articles basally, longer medially and distally. Neuropodia less prominent than notopodia; long papillae mostly postchaetal. From chaetiger 4, 6–7 multiarticulate bidentate neurohooks, arranged in a J-shape. Anterior and median chaetigers with neurochaetae with long articles ( Fig. 11 E); posterior chaetigers with 4–5 long articles. Tips bidentate, accessory tooth thin.

Posterior end damaged in Virginia specimens (specimens from Alabama and another one from North Carolina with terminal anus (another specimen with dorsoterminal anus), without anal cirri, but with marginal papillae, and a ventral elongated lobe).

Remarks. Piromis websteri Day, 1973 , originally described as a subspecies, does closely resemble P. k is e m - boanus, but differs sufficiently to warrant full species status and is herein so elevated. Piromis websteri and P. kisemboanus differ in the relative size of the sediment particles that adhere to the tunic and on the relative number of notochaetae. Thus, in P. w e b s t e r i the sediment grains are fine and there are about eight notochaetae per bundle, while in P. kisemboanus the sediment particles are larger and there are about four notochaetae per bundle.

Distribution. Intertidal or shallow water in Virginia, North Carolina and in the Gulf of Mexico.

Figures

FIGURE 11. Piromis websteri Day, 1973, st. n. A. Syntype (USNM 433), complete, lateral view. B – F: non-type specimen (USNM- 53883). B. Anterior end, dorsal view. C. Anterior end, ventral view, head exposed (Br: branchiae, CH: cephalic hood, DL: dorsal lip, LL: lateral lip, Pa: palp, PK: palp keel, VL: ventral lip). D. Notochaetae from chaetiger 20, showing basal, medial and distal regions. E. Neurochaetae from chaetiger 35, insert showing tips. G. Neurochaetae from chaetiger 125, insert showing tips. Scale bars: A: 2.5 mm, B – C: 0.5 mm, D: 70 µm, E: 150 µm, F: 50 µm.