Piromis kisemboanus ( Augener, 1918 ), Augener, 1918
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|Piromis kisemboanus ( Augener, 1918 )|
Piromis kisemboanus ( Augener, 1918) n. comb.
Figure 7 View FIGURE 7
Stylarioides kinsemboanus Augener, 1918: 440 –442, Pl. 6, Fig. 150, Pl. 7, Fig. 214, Text fig. 64; Fauvel & Rullier, 1959: 181; Amoureux, 1973: 61.
Type material. Not available in ZMH, probably lost (A. Brandt 2004, pers. comm.).
Additional material. Northwestern Africa. One specimen (MNHN- 507), Pointe Bernard (13 ° 39 ʹ 19 ʺ N, 17 ° 25 ʹ 53 ʺ W), Dakar, Senegal, no date, R. Lourie (coll.). One specimen ( USNM unnumbered), anterior fragment, off Route de la Corniche, near Musee Dynamique, Dakar, Senegal, heavy surf, sandy beach, 24 Jun. 1968, M.E. Rice, coll.
Description. Specimen complete (MNHN-A 507), almost broken in two parts ( Fig. 7 View FIGURE 7 A). Body clavate, slightly tapering posteriorly; tunic papillated, with large sediment particles over dorsal surface ( Fig. 7 View FIGURE 7 B), extending to pygidium; smaller particles present laterally extending to neuropodia. Papillae arranged in longitudinal rows, barely exposed dorsally, arranged as four papillae per segment, more exposed ventrally ( Fig. 7 View FIGURE 7 B), four papillae per segment. Body 20.5 mm long, 2.0 mm wide, cephalic cage 3.0 mm long, 52 chaetigers.
Anterior end observed by dissection. Cephalic hood short, margin smooth. Prostomium elevated, continued posteriorly as a darker short cone; two large black eyes present (posterior eyes not visible). Caruncle well developed, extending to branchial plate margin, median keel and lateral ridges pale. Branchiae with dark, discontinuous spots, about 20 per lateral group. Palps pale brown, about three times as long as branchiae. Palp lobes rounded, elevated. Dorsal lip darker, lateral and ventral lips unpigmented. Nephridial lobes not seen.
Cephalic cage present, chaetae 1 / 7 as long as whole body, or 1 / 3 longer than body width. Chaetigers 1–3 involved in the cephalic cage; chaetae arranged in short rows, dorsolateral in chaetiger 1, lateral in following chaetigers; 5–6 chaetae per fascicle. Anterior dorsal margin of first chaetiger medially depressed, with a sand grain on it. Anterior, median, and posterior chaetigers with long notopodial papillae, about 1 / 3 as long as notochaetae; chaetigers 2–8 with low lobes, resembling posterior ones. Chaetigers 1–3 of about the same length. Chaetal transition from cephalic cage to body chaetae abrupt; multiarticulated simple neurohooks start in chaetiger 5. Gonopodial lobes not seen.
Parapodia well developed, lateral; median neuropodia ventrolateral. Noto- and neuropodia with long chaetal lobes and long digitate papillae ( Fig. 7 View FIGURE 7 D); 1–2 prechaetal and 2 postchaetal papillae per rami.
Median notochaetae arranged in a transverse row, four per bundle, each about half as long as body width; all notochaetae multiarticulated capillaries, each with short articles basally, medium-sized medially, long distally ( Fig. 7 View FIGURE 7 E). Neurochaetae multiarticulated capillaries in chaetigers 1–4; multiarticulate simple hooks from chaetiger 5, arranged in a transverse row ( Fig. 7 View FIGURE 7 F), posteriorly in oblique row ( Fig. 7 View FIGURE 7 G), 4–5 throughout the body (more chaetae in larger specimens). Neurohook handle with short anchylosed articles basally, a variable number of long median articles, and longer cylindrical distal part with a single curved fang.
Posterior end truncate; pygidium with terminal anus, without anal cirri.
Remarks. Piromis kisemboanus ( Augener, 1918) n. comb., might resemble P. arenosus if the sediment cover extended throughout the whole body, or it might be closer to P. w e b s t e r i Day, 1973 n. status if the sediment cover is restricted to the dorsal and lateral surfaces. The issue is that in the original description, the ventral surface was depicted as including fine sediment particles, and the lack of type materials requires a double inclusion in the key and a comparison to two sets of similar species. Thus, P. kisemboanus differs from P. arenosus by having longer notopodial papillae (about 1 / 2 – 1 / 3 as long as notochaetae) than in P. arenosus (about 1 / 4 – 1 / 5 as long as notochaetae), and in the shape of the distal article in neurohooks, such that in P. kisemboanus they are cylindrical, tapering, mostly unidentate, while in P. arenosus they are medially widened and bidentate. On the other hand, by having sediment cover restricted to the dorsal and lateral surfaces and a negligible amount of sediment grains ventrally, the most closely related species to P. kisemboanus would be P. w e b s t e r i. They differ in that the former has larger sediment grains on the tunic and about four notochaetae per bundle, while the latter has fine sediment grains on the tunic and about eight notochaetae per bundle.
Both, Monro (1933) and Day (1955), regarded S. kinsemboanus Augener, 1918 , as a junior synonym of Piromis arenosus Kinberg, 1867 . Since the neurohooks are bidentate in the latter, they regarded the accessory tooth in the former as fragile; however, there are two other differences in the relative size of the notopodial papillae and in the terminal articles in neurochaetae. Thus, P. kisemboanus is closely allied to P. arenosus but differs from it by having longer parapodial papillae, and cylindrical or tapering neurochaetae, instead of being distally expanded.
The type locality was written as Kinsembo; however, the name for this place in the Zaire Province of Angola should rather be Kisembo (07° 43 ʹ0 6 ʺ S, 13 °03ʹ0 0ʺ E), which in turn has been written as Kiusembo, and even as Quicembo, but Kinsembo is orthographically incorrect and hence the spelling of the species epithet must be corrected. The best specimen (MNHN-A 507), was collected far from the type locality, but it originates from tropical Western Africa, probably from shallow water, and is regarded as belonging to this species.
Distribution. Subtropical and tropical Western Africa, in shallow water.
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