Eupolymnia turgidula Ehlers 1887
Creators: name: Nogueira, João Miguel De Matos
name: Harris, Leslie
name: Hutchings, Pat
name: Fukuda, Marcelo Veronesi
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Terebellidae
Eupolymnia
Eupolymnia turgidula

description: Eupolymnia turgidula (Ehlers, 1887)
Figures 9–10
Terebella turgidula Ehlers, 1887: 241 – 245, Taf. 52, Figs. 1–4.
? Terebella crassicornis Schmarda, 1861: 43, Figs. A–C; Augener 1925: 36 –37.? Terebella magnifica Webster, 1884: 324, Pl. XI, Figs. 58–60.
Not Terebella turgidula. Londoño-Mesa 2009: 63 –64, Fig. 18D–J.
Material examined. Holotype (MCZ 846): incomplete specimen in poor state of preservation (see below), ~ 15 mm long, 2 mm wide; coll. USA, Florida, Key West, 2–4 m, Blake Expedition, by A. Agassiz, 1877–1878. Slides: notochaetae from segment 18; neurochaetae from segments 7, 12, and 23.
Description. Holotype incomplete specimen, with region with biramous parapodia and ~26 segments with neuropodia only, in poor state of preservation, nearly torn midway along region with biramous parapodia and also at transition between regions with biramous parapodia and with neuropodia only. Pieces of tube together with specimen; mucous, transparent, with some embedded coarse shells (Fig. 9 K). Body slightly inflated dorsally after segment 4 (Fig. 9 B, G–H). Ventral shields on segments 3–18, all corrugated, more evident on anterior segments (Fig. 9 C–G, I); shields progressively wider on segments 3–5, then progressively narrower until last shield; anterior shields short and compact, progressively longer from segment 10, last shield distinctly shorter (Fig. 9 C–G, I); after segment 18, shields continue as mid-ventral stripe extending posteriorly. Prostomium at base of upper lip; distal part forming shelf-like process from which buccal tentacles originate (Fig. 9 B–H); eyespots still conspicuous at least at left lateral of basal part of prostomium, apparently forming continuous row, laterally broader, distinctly thinner mid-dorsally. Peristomium restricted to lips; upper lip short, broader than long; lower lip short, almost completely covered by ventral lobe on segment 1 (Fig. 9 B–H). Segment 1 short, more developed ventrally, with ventral lobe around and below lower lip (Fig. 9 C–G). Segment 2 with one pair of relatively large, rounded ventro-lateral lobes, connected to each other by low flap across ventrum (Fig. 9 C–G). Segments 3–4 with short, rounded ventrolateral lobes, progressively more laterally placed, those on segment 3 larger and connected to each other by crest across ventrum (Fig. 9 C, E–G). Three pairs of branchiae on segments 2–4, with short, stout and annulated cylindrical basal stems branching to short distal filaments; branchiae progressively shorter and vertically aligned, last pair distinctly shorter than other pairs (Fig. 9 B–C, E–H). Seventeen pairs of notopodia, starting on segment 4 and extending to segment 20; notopodia relatively long. Narrowly winged, distally smooth notochaetae on both tiers, those from posterior tier about twice as long as those on anterior tier, with limbation on distal half of chaetae (Fig. 10 A–B). Neuropodia starting on segment 5, as low rectangular ridges slightly raised from surface of body until segment on which notopodia terminate (Fig. 9 C–G, I), as long, foliaceous pinnules thereafter, with internal shafts and small, spherical dorsal lobe, first two pinnules much shorter than following ones (Fig 9 I–J). Short-handled uncini throughout, about as long as high on region with biramous parapodia, with pronounced dorsal button situated closer to tip of prow than base of main fang, distally rounded prow and crest with 2 rows of secondary teeth, first row with two large teeth, second row with single minute tooth placed between teeth of first row, often not visible in lateral view (Fig. 10 C–E); uncini in completely intercalated double rows from segment 11 until segment on which notopodia terminate (Fig. 10 E); from segment 21, uncini longer than high, with distally pointed prow, otherwise as those on region with biramous parapodia (Fig. 10 F). Nephridial papillae on segments 3–5, between parapodial lobes on segment 5, in equivalent position on segments 3–4 (Fig. 9 E–G), genital papillae not visible. Pygidium unknown.
Remarks. The state of preservation prevents the proper evaluation of some characters, such as the alignment of the first pairs of notopodia and the position of neuropodial papillae in relation to the mid-ventral stripe in the region with neuropodia only.
As discussed by Londoño-Mesa (2009), E. turgidula was described as a species of Terebella Linnaeus, 1767. Hessle (1917) transferred it to the genus Polymnia Malmgren, 1867, which was changed to Eupolymnia by Verrill (1900). Augener (1925) then synonymized it with E. crassicornis, which was subsequently followed by Hartman (1938), Rullier (1974), and Holthe (1986).
Recently, Londoño-Mesa (2009) resurrected this taxon as a species of Terebella. However, the specimen Londoño-Mesa described and illustrated (his Figs. 18D–J) as the holotype is not the same specimen that was sent to us, although the catalog number quoted by Londoño-Mesa (2009) is the same as the specimen we examined (MCZ 846). We are at a loss to explain this discrepancy. Londoño-Mesa’s specimen is 210 mm long with 140 segments, it does not have lobes on anterior segments, it has 27 pairs of notopodia and distally serrated notochaetae. Ehlers stated that his specimen was 31 mm long for 53 segments, had 18 pairs of notopodia, and had lobes on anterior segments (clearly illustrated in Ehlers, 1887, Taf. 52, Fig. 1, included here as Fig. 9 A).
Although the specimen sent to us as the holotype of E. turgidula is in poor condition compared to the drawing provided by Ehlers, and is no longer complete and with the body severely damaged in places, we have no doubt we are dealing with the same specimen (see Fig. 9 A–G).
The specimen Londoño-Mesa (2009) examined and illustrated definitely belongs to Terebella, as it does not present lobes on anterior segments and has a large number of pairs of notopodia (27 pairs, against 17 as in most, if not all, species of Eupolymnia) bearing distally serrated notochaetae.
The question of the validity of the taxon E. turgidula is complicated. Schmarda (1861) described E. crassicornis as having 25 pairs of notopodia and uncini with a single row of three secondary teeth. Augener (1925) based the synonymization of E. turgidula with E. crassicornis on the similarity between the uncini of both species and his belief that E. crassicornis should have only 17 pairs of notopodia despite Schmarda’s statement to the contrary. In addition to the problem concerning the numbers of pairs of notopodia present in both species, the holotype of E. turgidula has uncini with two rows of secondary teeth and, although the second row is difficult to discern, depending on the position of the uncini on the slide, the first row clearly has only two teeth (see Fig. 10 C–F). Moreover, the general morphology of the uncini of these two taxa, which Augener considered very similar to each other, is considerably different in our opinion, especially considering the shape of the dorsal button, prow, base, and heel (compare Schmarda’s illustration provided by Londoño-Mesa [2009: 30, Fig. 7 C] with our Fig. 10 C–E).
Londoño-Mesa (2009) listed three species of Eupolymnia for the Caribbean: E. crassicornis, E. magnifica (Webster, 1884), and E. rullieri Londoño-Mesa, 2009. Eupolymnia rullieri is clearly a separate taxon from E. turgidula, differing mostly in the position of the genital papillae and in the uncinial dental formula.
However, we could not detect any consistent difference between the redescription of E. magnifica provided by Londoño-Mesa (2009) and our redescription above of the holotype of E. turgidula, except for a great difference in body size. Londoño-Mesa (2009) said the best syntype of E. magnifica had nephridial papillae on segments 3–5 as also occurs in the holotype of E. turgidula. Other specimens examined by Londoño-Mesa (2009) also had papillae on segments 6–10 but it was not specified as to whether these were in addition to the nephridial papillae on segments 3–5 or if they were on type or non-type material. These specimens need to be re-examined to confirm that they belong to the same taxon.
We consider that E. turgidula is very likely a junior synonym of E. magnifica, instead of E. crassicornis. However, we prefer to keep E. turgidula as a valid taxon until more detailed studies on these taxa are carried out. The holotype of E. crassicornis, described as dried by Augener (1925), now appears to be missing (pers. com., S. Szeiler, Naturhistorisches Museum, Wien) and a neotype would have to be erected to stabilize the species and resolve the question of synonymy. However, considering all the problems to characterize this taxon discussed above, it is not possible to erect a neotype at this stage and therefore this taxon should be considered as undeterminable, if the holotype is not found.
description: Published as part of Nogueira, João Miguel De Matos, Harris, Leslie, Hutchings, Pat & Fukuda, Marcelo Veronesi, 2011, Four terebellines (Polychaeta, Terebellidae) with problematic taxonomic histories, pp. 1-26 in Zootaxa 2995 on pages 20-24, DOI: 10.5281/zenodo.278414