Armandia dolio Parapar & Moreira, 2015, n. sp.
Creators: name: Parapar, Julio
name: Moreira, Juan
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Opheliidae
Armandia
Armandia dolio

description: Armandia dolio n. sp.
(Figs 1 B, 2C, 4–5, 18B)
Material examined. Eight specimens in four samples. Holotype: AM W.44241, MI QLD 2373. Paratypes: AM W.43898, MI QLD 2333 (2); AM W.47320, MI QLD 2373 (2); AM W.47321, MI QLD 2373, on SEM stub; AM W.45399, MI QLD 2440; AM W.44557, MI QLD 2330, in EtOH.
Diagnosis. Parapodia biramous, with prechaetal lobe and ventral lobe; prechaetal lobe symmetrical, with a notch giving distal border a bilobed appearance. Anal tube barrel-shaped, straight at base, increasing width at midline and tapering again towards distal end; anal tube opening directed posteriorly, not laterally compressed; posterior border provided with 10 pairs of short paired anal cirri of different length, about 1/5 as long as anal tube length; internal unpaired anal cirrus and pair of basal cirri present.
Description. Based on holotype. Specimen complete, 8.0 mm long and 1.0 mm wide, with 29 chaetigers. Body slender, slightly tapering towards anterior and posterior ends. Prostomium conical, palpode short and clavate (Figs 4 A, 5A). A pair of small red eyes deeply embedded in prostomium (Fig. 4 A). One pair of ring-shaped nuchal organs (Fig. 5A–B); pharynx eversible (Fig. 4 A), oral tentacles not seen. Branchiae present from CH 2– CH 26, long, almost reaching dorsal midline, not decreasing in length in posterior chaetigers. Parapodia biramous, with prechaetal lobe and ventral lobe (Figs 4 C–H, 5C–D); dorsal cirrus from CH 4. Prechaetal lobe symmetrical, with a notch giving distal border a bilobed appearance (Fig. 4 C–H). Lateral eyespots anterior to parapodia on 11 chaetigers (CH 7– CH 17); orange, horizontally oval, those of CH 7 and CH 16– CH 17 smaller than others. Simple, very long capillary chaetae in two bundles; notochaetae generally longer than neurochaetae (Fig. 5A, E). Anal tube barrel-shaped, straight at base, increasing width at midline and tapering again towards distal end, as long as last four chaetigers (Figs 4 B, 5E–F). Anal tube opening directed posteriorly, not laterally compressed. Posterior border provided with 10 pairs of short paired anal cirri of different length, about 1/5 as long as anal tube length (Figs 4 B, 5F); internal unpaired anal cirrus and pair of basal cirri not seen (but present in several paratypes, see below).
Remarks. The most remarkable diagnostic feature of Armandia dolio n. sp. is the unique shape of the anal tube. Observations on live specimens showed that the anal tube seems to be somewhat flexible allowing some degree of variation in its shape, i.e. sometimes looking either inflated or deflated (Fig. 2 C). The anal tube of fixed specimens does, however, always show a conspicuous inflated shape (Figs 4 B, 5E).
Paratypes measure about 6–10 mm in length and 0.5–0.9 mm in width; these specimens have the same of numbers of chaetigers and the presence of prostomial eyes as the holotype. In contrast, two paratypes (AM W.47320 and AM W.43898) show an unpaired anal cirrus and fewer paired anal cirri (<7). The first chaetiger and the last three ones (CH 27– CH 29) also lack branchiae and the parapodia show a small dorsal elevation at the level of the postchaetal lobe as well (Fig. 4 C, H). Furthermore, the anal tube apparently lacks paired basal cirri.
The closest species to A. dolio n. sp. is A. paraintermedia n. sp. (see below) according to general body shape but they differ in the shape and features of the anal tube. Thus, A. dolio n. sp. has a large, barrel-shaped anal tube while in A. paraintermedia n. sp. the paired anal cirri are comparatively longer and larger when compared to the size of the anal tube.
Etymology. The epithet dolio (L.) refers to the barrel-shaped anal tube.
Habitat / Distribution. Sublittoral (5–14 m) on muddy sand. Most specimens (87.5%) were collected at Vicki’s reef, in front of Palfrey Island and remaining ones at NW of Watson’s Bay (Fig. 1 B).
description: Published as part of Parapar, Julio & Moreira, Juan, 2015, Six new species of the genus Armandia Filippi, 1861 (Polychaeta, Opheliidae) from Lizard Island (Great Barrier Reef, Australia), pp. 577-603 in Zootaxa 4019 (1) on pages 582-585, DOI: 10.11646/zootaxa.4019.1.19, http://zenodo.org/record/241350