Loimia bermudensis Verrill, 1900

Londoño-Mesa, Mario H., 2009, Terebellidae (Polychaeta: Terebellida) from the Grand Caribbean region 2320, Zootaxa 2320 (1), pp. 1-93 : 37

Loimia bermudensis Verrill, 1900

Figures 9 A-H

Loimia bermudensis, Verrill, 1900:664–665 .

Type material: Syntypes YPM 1018 (1) Bermuda, 1900; coll. A.E. Verrill, Exp. YPM 1088 (1) Bailey Bay , Bermuda, 1898; coll. A.E. Verrill, Exp. Low water, under stones (in poor condition). Slide YPM 36713–14 (notopodia and neuropodia, in poor condition) .

Description: Best syntype ( YPM 1018) incomplete, with 33 segments, 29mm long, thorax 17mm long, 5mm wide ( Fig. 9A ). Tentacular membrane short, narrow, rounded edge with mid-dorsal discontinuity dividing membrane in two; eyespots absent; tentacles missing. Upper lip short, narrow, damaged. Lower lip short, hidden by segment 1 ( Fig. 9B ). First pair of lateral lappets projecting forwards, with well-developed lateral margins laterally surrounding tentacular membrane ( Fig. 9C ), and ventrally lower lip; second pair damaged, with wide base, not connected to ventral shield, and with dorsal edge almost as long as first lateral lappet, slightly developed, not covering base of branchiae. Ten ventral shields from segment 3; first shield shorter; second shield the largest, divided in two, with anterior portion shorter; next three shields decreasing in size posteriorly; last 5 shields all of similar size. Next thoracic segments with smooth ventral gap between neuropodia. Abdomen without mid-ventral longitudinal groove. Nephridial papillae not seen. Notopodial glandular tissue absent. Branchiae branched, spiralled, but damaged in the specimen ( Fig. 9D ). Notochaetae of two lengths, unilimbate, pointed; chaetae with some longitudinal striations ( Fig. 9E ) appear as fringes due to chaetal damage. Uncini from segment 5–10 pectinate ( Fig. 9F ), with five aligned equal-sized teeth; PP developed, angular; PF absent; Oc long, concave; Cp with 1 vertical row of five teeth, equal-sized; USr concave; SrP absent; LSr convex; AP with thin and long AF, projected downward; Bs strongly convex. Uncini from segments 11–20 ( Fig. 9G ) pectinate, with five aligned equal-sized teeth; abdominal uncini pectinate, smaller ( Fig. 9H ), with five aligned equal-sized teeth. Abdominal neuropodia well developed, as swollen lappets with short rows of uncini. Pygidium missing.

Variation: It is not possible to find variation since the second syntype ( YPM 1088 ) is in poor condition and there are no more additional specimens. Moreover, the slides are also in poor condition .

Discussion: This species was synonymized with L. medusa (Savigny in Lamarck, 1822) by Hartman (1942). Nevertheless, although L. bermudensis is similar to L. medusa in terms of the number of teeth in both thoracic and abdominal uncini, they differ in the shape of the uncini. L. medusa has uncini with teeth decreasing in size, and uncini with a well-developed subrostral process. This uncinal condition could give an appearance of the uncini as being avicular. In contrast, L. bermudensis has uncini with teeth almost all the same size, without a major variation in the size, and uncini without subrostrum process; this uncinal condition gives the uncini its pectinate appearance. Thus, it could be possible that some material from the Grand Caribbean reported as L. medusa may belong to L. bermudensis . A revision of the genus Loimia is almost completed and will be published by the author and collaborators in the near future.

Type locality and distribution: Bailey Bay , Bermuda .

Figures

FIGURE 9. Loimia bermudensis (Syntype YPM 1018): A. Anterior thoracic region in ventral view. B. Anterior end in ventral view. C. Anterior thoracic region in dorsal view. D. Anterior end in dorsal view. E. Unilimbate notochaetae from segment 11. F. Uncinus from segment 5. G. Uncinus from segment 11. H. Uncinus from segment 25. Scale bars: A,C: 4mm; B,D: 1.5mm; E: 0.05mm; F,G,H: 0.02mm.