Pycnoderma ferruginea Gallardo 1968, n. comb.
Creators: name: Salazar-Vallejo, Sergio I.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Flabelligeridae
Pycnoderma
Pycnoderma ferruginea

description: Pycnoderma ferruginea (Gallardo, 1968) n. comb.
Figure 16
Brada ferruginea Gallardo, 1968:107 –108, Pl. 49, Figs. 5–6.
Piromis congoensis Gallardo, 1968:109 –110, Pl. 51, Figs. 1–7 (non Grube, 1877).
Type material. Western Tropical Pacific. Holotype of Brada ferruginea Gallardo, 1968 (LACM-AHF -312), off West side of Hon Lon Island, Bay of Nha Trang, Viet Nam, Naga Expediton, R/V Mao Tien, Sta. 117 (12°11ʹ21ʺ N, 109°16ʹ15ʺ E), 12 m, 10 Feb. 1960, V.A. Gallardo, coll.
Additional material. Western Tropical Pacific. One mature female (LACM-AHF-2515), broken in two pieces, 4 km N Hon Ho island, Viet Nam, Naga Expediton, R/V Mao Tien, Sta. 153I (12°19ʹ20ʺ N, 109°21ʹ40ʺ E), 43 m, mud, 24 Feb. 1960 (cephalic cage chaetae length equivalent to the anterior end up to chaetiger 18). Anterior fragment (LACM-AHF-2516), 2 km NW Hon Ho Island, Bay of Nha Trang, Viet Nam, Naga Expedition, R/V Mao Tien, Sta. 15411 (12°18ʹ0 6ʺ N, 109°21ʹ27ʺ E), 43 m, mud, 24 Feb. 1960, V.A. Gallardo, coll. (cephalic cage chaetae length equivalent to the anterior end up to chaetiger 14).
Description. Holotype (LACM-AHF-312) broken into three parts, anterior fragment reddish, especially anteriorly, with most chaetae directed forward, median and posterior fragments pale (Fig. 16 A), all cylindrical; tunic thin, densely papillated, fine red sediment particles anteriorly; papillae mostly small, thin, cirriform, abundant all over the body, and few longer, capitate, isolated, along body in 2–3 regular rows, and others close to parapodia. Holotype 46(15+4+27) mm long, 2.5 mm wide, cephalic cage 5.5 mm long, 65(28+7+30) chaetigers.
Cephalic hood partially exposed in holotype, short, margin papillated. Anterior end observed in another specimen (LACM-AHF-11153); cephalic hood very short, margin papillated. Prostomium depressed, eyes not visible; caruncle short, not reaching posterior margin of branchial plate (Fig. 16 E), lateral ridges short, prominent, extending towards lateral bases of branchiae. Palps lost; palp keels rounded. Lateral lips wide, well-developed; dorsal and ventral lips reduced. Branchiae mostly lost, cirriform, pale (LACM-AHF-11154), sessile on branchial plate, widely separated medially into two groups, over a tongue-like protuberance, branchial groups posteriorly coalescent, with about 100 filaments per side. Size relationships between palps and branchiae unknown.
Cephalic cage chaetae more than twice as long as body width (Fig. 16 B). Only chaetiger 1 involved in cephalic cage, notochaetae of chaetiger 2 less than twice as long as following ones. Cephalic cage notochaetae arranged in a short dorsal row, neurochaetae as a long lateral row (Fig. 16 D); 8–10 notochaetae and 12–15 neurochaetae per bundle, longest about 1/4 as long as notochaetae. Anterior dorsal margin of chaetiger 1 short, papillated (Fig. 16 C). Anterior chaetigers without long papillae. Chaetigers 1–3 decreasing in size anterior to posterior, second parapodia displaced dorsally. Post-cephalic cage chaetigers not elongated; a white rounded dorsal spot present on posterior margin of chaetiger 1. Chaetal transition from cephalic cage to body chaetae gradual; compound neurohooks from chaetiger 16. Gonopodial lobes in chaetiger 5, low, pale, rounded.
Parapodia poorly developed, lateral. Median neuropodia lateral. Notopodia low, thin lobes, with 3–4 long capitate papillae. Neuropodia slightly longer lobes, with some superior and inferior long capitate papillae.
Median notochaetae in short transverse row, 6–8 per bundle, 3/5 as long as body width, posterior notochaetae twice as long as body width; notochaetae all multiarticulated capillaries with very long articles (Fig. 16 F), continuing to tip. Neurochaetae similar to notochaetae in anterior chaetigers, arranged in transverse row. Neurohooks from chaetiger 16, 6–8 per bundle, each with feebly marked, anchylosed short articles basally, followed by 2–5 long articles, with long, lanceolate, aristate blade (Fig. 16 F).
Posterior end unknown.
Remarks. Pycnoderma ferruginea (Gallardo, 1968) n. comb. was placed in the genus Brada because of the presence of ventral lobes in chaetiger 5. However, the cephalic cage, the body shape, and the type of neurochaetae are very different from those of Brada, and this species is therefore here referred to Pycnoderma, and hence the new combination: P. ferruginea (Gallardo, 1968).
The description of B. talehsapensis by Fauvel (1932) and its redescription (Fauvel 1953) were not overlooked by Gallardo (1968), but he confused the species when comparing his specimens to Fauvel’s species, which is a close relative. The two species differ in the relative size of the cephalic cage and in the pigmentation pattern of the branchial filaments. In B. ferruginea, chaetal length of the holotype is about the same over the first 13 chaetigers; this relative size of cephalic cage chaetae is confirmed in two other specimens being 1 mm wide, which have these chaetae being as long as reaching chaetigers 12 or 17. In contrast, in B. talehsapensis the cephalic cage chaetae are shorter, with their length being about the same as the length of the anterior end up to chaetiger 7. Further, the branchial filaments are homogeneously pale in P. ferruginea whereas they are banded in P. talehsapensis.
These two species were included in Brada by Fauvel, because they have on the fifth chaetiger “… the nephridial papillae characteristic of the genus Brada ʺ (Fauvel 1932:185). Four paragraphs above, however, he indicated that its “… general appearance is rather unusual for the genus, the body being generally short with few segments, whilst in this species it is long, vermiform and has numerous segments.ʺ
On the other hand, P. ferruginea resembles P. escobarae n. sp. (see above). Both species have opaque tunics with papillae and notochaetae with very long articles. They differ because P. ferruginea has twice as many notochaetae, the body is more papillose, and the papillae are longer. They also differ in the relative number of articles per neurospine because in P. ferruginea there are only two articles whereas in P. escobarae, neurospines have mostly three articles with a smaller median one. In addition, these two species occur in different oceans and water depths.
Distribution. Restricted to the Gulf of Nha Trang, Vietnam, in shallow water (12–30 m).
description: Published as part of Salazar-Vallejo, Sergio I., 2011, Revision of Piromis Kinberg, 1867 and Pycnoderma Grube, 1877 (Polychaeta: Flabelligeridae), pp. 1-50 in Zootaxa 2819 on pages 36-38, DOI: 10.5281/zenodo.277211