Piromis eruca ( Claparède, 1868 ), Claparede, 1868

Salazar-Vallejo, Sergio I., 2011, Revision of Piromis Kinberg, 1867 and Pycnoderma Grube, 1877 (Polychaeta: Flabelligeridae), Zootaxa 2819, pp. 1-50 : 16-18

Piromis eruca ( Claparède, 1868)

Figure 5

Trophonia eruca Claparède, 1868:105 –107, Pl. 25, Fig. 2 A–C; Lo Bianco, 1893:43 –44. Stylarioides eruca: Fauvel, 1927:119 , Figs. 42h–l (syn.; partim).

Piromis eruca: Day, 1973:108 –109 (redescr.); Castelli, 1990:14.

Type material. Mediterranean Sea. Neotype (MNHN-507), and paraneotype (MNHN-507a), Naples, 1910; no further data.

Additional material. Mediterranean Sea. Three specimens (MNHN-185) without data, collection of de Saint-Joseph-20 (two with the anterior end exposed; about 50 branchial filaments per side; anterior margin of chaetiger 1 with a foliose, wide anterior lobe; chaetigers 2–4 with tubercles around dorsal papillae). One specimen (MNHN-457), Naples, no further data, S. Lo Bianco coll. (complete specimen, anterior end exposed; about 50 branchial filaments per lateral group). Two specimens (MNHN-507) damaged, most with chaetae broken, one complete, anterior end exposed, some parts broken off, Naples, 1910, without further data.

Description. Neotype complete ( Fig. 5 A); body tapering posteriorly, pale brown, sediment particles abundant, loosely packed, leaving body wall partially uncovered ( Fig. 5 B, C); anterior region slightly bent over its ventral side; tunic papillated. Large capitate papillae arranged in longitudinal rows, two rows dorsally, four rows ventrally; body 43 mm long, 3 mm wide, cephalic cage 5 mm long, 80 chaetigers.

Cephalic hood exposed in neoparatype, margin smooth; anterior end dissected in neoparatype. Prostomium short, pale; eyes dark, faded. Caruncle well-developed, extending to tip of branchial plate, median keel pale, lateral ridges pale ( Fig. 5 D). Palps corrugated; palp keels rounded, elevated, pale. Dorsal lip short; lateral lips thicker, ventral lip reduced. Branchiae cirriform, arising on tongue-like protuberance, in two lateral groups (completely separated in a non-type specimen, Fig. 5 E), each with branchiae arranged in 4–5 concentric rows, or about 12 oblique rows, basal ones with more branchiae, each group with about 40 filaments. Nephridial lobes not seen.

Cephalic cage chaetae about 1/8 as long as body length, twice as long as body width. Chaetigers 1–4 involved in the cephalic cage; chaetae arranged in short rows, dorsolateral in chaetiger 1, lateral in chaetigers 2–4; chaetiger 1 with 5–6 noto-, 5–6 neurochaetae per bundle, chaetigers 2–4 with 7–8 noto- and 5–6 neurochaetae per bundle. Anterior dorsal margin of first chaetiger with a trifid lobe. Anterior chaetigers with long papillae, chaetigers 2–6 with notopodial lobes. Chaetigers 1–3 of about the same length. Chaetal transition from cephalic cage to body chaetae abrupt; shorter multiarticulate bidentate neurohooks from chaetiger 5. Gonopodial lobes not seen.

Parapodia well developed, rounded dorsal lobes in anterior chaetigers (1–6). Parapodia lateral, median neuropodia ventrolateral. Noto- and neuropodia with long chaetal lobes and long digitate papillae; notopodia with two, rarely three smaller papillae, neuropodia with three larger prechaetal papillae, both with three larger postchaetal ones.

Median notochaetae arranged in a short transverse row, eight per bundle, slightly less than half as long as body width, thinner than neurochaetae; all notochaetae multiarticulated capillaries, each with short articles basally, medium-sized medially, longer distally ( Fig. 5 F), tip hooked. Neurochaetae multiarticulated capillaries in chaetigers 1–4; multiarticulated bidentate hooks from chaetiger 5, arranged in a transverse row in all chaetigers; six neurohooks in anterior and median chaetigers ( Fig. 5 G), up to five in posterior chaetigers ( Fig. 5 H). Each neurohook with short articles basally, then few articles becoming progressively longer, then decreasing in size towards distal article (6–10 times longer than wide). Tips hooked, bidentate; accessory tooth flat, wide, as long as the fang.

Posterior end blunt, rounded; pygidium contracted, anus dorso-terminal, without anal cirri.

Variation: Paraneotype complete, mature female; sediment grains large, more abundant dorsally; with two longitudinal rows of papillae dorsally, four ventrally. Paraneotype 25.5 mm long, 3 mm wide, cephalic cage 4.5 mm long, 73 chaetigers; chaetigers 1–6 with projecting, acute, conical lobes, decreasing posteriorly, in following chaetigers very reduced. Most notopodia with two pre- and three postchaetal papillae, each long, capitate, in posterior chaetigers there can be up to 4 additional ones under the neurochaetal lobe. Anterior end slightly exposed. Neurochaetae of chaetigers 1–4 long; shorter in chaetiger 4, smaller thereafter; oocytes about 100 µm.

Remarks. Piromis eruca ( Claparède, 1868) resembles P. s u n i n. sp. from the Western Pacific Ocean because both have large sediment particles on the tunic, notopodial lobes in anterior chaetigers, and neurohooks from chaetigers 4–5. They are so similar that some records from Japan and other Western Pacific localities have been referred to the Mediterranean species. They differ, however, in the relative size of neurochaetal articles from median and posterior chaetigers, because there are few, longer articles in P. e r uc a, while there are many medium-sized articles in P. suni n. sp.

Piromis eruca ( Claparède, 1868) was redescribed by Day (1973). Records from areas beyond the Mediterranean Sea or other distant regions are questionable and belong to another species (see below). The British Columbia specimen, judging by the illustrations ( Hobson & Banse 1981:59, Fig. 11 k, l), apparently belongs in Trophoniella . On the other hand, the original description indicated about 24 branchial filaments; however, Fauvel (1927:119) stated that there could be either 8–10, or 50–60. The paraneotype is from Naples, the type locality, and has about 40 branchial filaments, and another specimen from the same place has about 50 filaments. Because of the supposed very wide variation in the number of branchial filaments, a neotype is being designated and it is redescribed to better define the species. Further, the posterior parapodia from these Naples specimens have bidentate multiarticulated neurochaetae, which confirms that Trophonia eruca belongs in Piromis , and that Balanochaeta is a junior synonym for Piromis . After studying all of Fauvel’s specimens available in Paris, it can be concluded that he combined under the same name two different species belonging to two different genera; one is the typical P. eruca herein restricted, while the other one, provided with few (10) branchial filaments, has anchylosed bidentate neurohooks in posterior chaetigers and belongs in Trophoniella .

Distribution. Mediterranean Sea, mixed or sandy sediments, shallow water.

Figures

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 5. Piromis eruca (Claparède, 1868). A. Neotype (MNHN-A 507), complete in lateral view. B. Same, anterior end, lateral view. C. Same, anterior end, dorsal view. D. Paraneotype, head, palps and branchiae detached (BS: branchial scars, DL: dorsal lip, LL: lateral lip). E. Non-type specimen (MNHN-A 185), exposed anterior end, palps and branchiae detached (BS: branchial scars, Ca: caruncle, Pr: prostomium, PS: palp scar). F. Paraneotype, notochaetal regions, basal, median, distal and an enlargement of the tip. G. Same, neurochaetae from a median chaetiger, insert showing one tip. H. Same, neurochaetae from a posterior chaetiger, insert showing one tip. Scale bars: A: 3 mm, B: 1 mm, C: 1 mm, D – E: 0.5 mm, F: 50 µm, G: 200 µm, H: 25 µm.

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.