Aricidea (Acmira) annae Laubier 1967
Creators: name: Erdoğan-Dereli, Deniz
name: Çinar, Melih Ertan
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Paraonidae
Aricidea
Aricidea annae

description: Aricidea (Acmira) annae Laubier, 1967
(Figures 2–3)
Aricidea annae Laubier 1967:106–112, fig. 2A–F, 3A–C.
Material examined. ESFM-POL/2013-1296, 09 June 2013, station Y17, 40°39’58’’N- 27°41’08’’E, 50 m, mud, 3 specimens.
Additional material examined. ESFM-POL/2017-151, 29 April 2017, Levantine Sea, off Kumluca, 36° 13’ 45”N, 30° 22’ 46”E, 67 m, sandy mud, 1 specimen.
Description. Largest specimen incomplete, 3.24 mm long, 0.44 mm wide, with 23 chaetigers. Color in alcohol yellowish or dull white. Body thick, widths of prebranchial and branchial regions nearly same; becoming gradually thinner from post branchial region to posterior end (Fig. 2A).
Prostomium almost half-hemisphere, wider than long (ratio length / width: 0.70); anterior part rounded (Figs 2B; 3A), without eyes, with three subequal annulations; annulation 1 (a1) almost subtriangular, making anterior part of prostomium, delineated by ciliary slits; annulation 2 (a2) large, making lateral parts of prostomium; annulation 3 (a3) narrow, making posterior part of prostomium. A ciliated band, termed as crown like ciliary band (clcb) present above nuchal organ surrounding prostomium, except for a gap in dorsal side (Figs 2B; 3A, C). A pair of deep ciliary slits (cs) located near anterior lateral sides of antenna; cilia located in posterior part (Fig. 3C). Antenna broken in all specimens; with a distinct, large, wrinkled antennophore (Fig. 3 C–D). A pair of nuchal organ as narrow deep, short slits, placed on dorso-lateral sides of posterior prostomium, more or less convex in shape; without dense internal ciliation; without pigmentation. In posterior part of prostomium, two rounded lobes present, laterally and partly ventrally surrounded by nuchal slits (Fig. 3C). Peristomium hardly discernable on dorsal and lateral sides, only in SEM, present as a skin fold, partly fused with anterior margin of chaetiger 1 (Fig. 3A, C). Mouth with three buccal lips; two placed anteriorly; one placed posteriorly, extending to anterior margin of chaetiger 1, with six longitudinal folds.
A dense dorsal ciliary band (dcb) present on mid-dorsal transversal line of each prebranchial and branchial chaetigers (Figs 2C; 3A). Short dorsal ciliary bands (sdcb) present as a transversal line located just posterior to base of each branchia (Fig. 3A). Ciliary bands absent on ventral side.
Branchiae eight pairs, from chaetiger 4: dorso-ventrally flattened, divided in two different parts, proximal one somewhat foliaceous, distal one digitiform with a rounded tip; 194 µm long in anterior region, 269 µm in middle region and 182 µm in posterior region; dense ciliary bands present on both sides of branchiae (Figs 2C; 3B). Interramal lobes present as indistinct ridge (irr) between noto- and neuropodium, starting from chaetiger 2 to end of branchial region (Fig. 2C).
Notopodial papilla absent. Notopodial postchaetal lobes short, thick and cirriform on first two chaetigers; long and thick between chaetiger 3–6; filiform on posterior chaetigers. Neuropodial postchaetal lobes short, thick and digitiform; only occurring between chaetigers 1 and 12. Ventral lobes absent.
Three main types of chaetae present on chaetigers: limbate, capillary and modified neurochaetae (Fig. 2C, F). Limbate chaeta of two types; first type present only on notopodia of chaetigers 1–10, arranged in 2–3 rows, numbering 14–15, ca. 196 µm long, thin and straight with fibrils along edge (hirsute), colorless; second type present only on neuropodia of chaetigers 1–10, arranged in 3–4 rows, numbering 12–16, ca. 164 µm µm long, much wider and sigmoid with fibrils along edge (hirsute), positioning dorsal to ventral in fascicle, colorless. (Figs 2C; 3A).
Capillary chaetae starting from on noto- and neuropodia of chaetiger 11 and present on all subsequent chaetigers; in middle notopodia numbering 11–12, arranged in two rows, 218 μm long; in posterior notopodia numbering 10– 11, arranged in one row, 121 μm long; in middle neuropodia numbering 5–6, arranged in 2–3 rows, 123 μm long; in posterior neuropodia numbering 2–3, arranged in one row, 174 μm long.
Three types of modified neurochaetae (Fig. 2 D–F) present from chaetiger 20 to end of body; type I modified neurochaeta long (average length: 108 µm), relatively thin, with a strong and thick arista at tip (Fig. 2D); type II short (average length: 38 µm), thicker than others, with a distal end curving at 90°, fibrils (hirsute) subterminally (Fig. 2E, F); type III short (average length: 25 µm), thick, with a curved distal end and a strong arista at tip, hirsute subterminally (Fig. 2E).
Pygidium missing.
Remarks. The specimens of Aricidea annae collected from the coasts of Turkey differ from the original description of the species by Laubier (1967) in having a wider body size (0.44 mm in the Sea of Marmara specimens vs. 0.3 mm in the original description) and an interramal lobe between notopodia and neuropodia. However, the interramal lobe is very small and placed between segments, so this character might have escaped the author’s attention.
Habitat and Distribution. Aricidea annae was found in muddy bottom at 50 m depth in the Sea of Marmara. It was previously reported from similar habitat between 35 and 100 m depths in the eastern (Çinar et al. 2014) and western (Laubier 1967) Mediterranean Sea.
description: Published as part of Erdoğan-Dereli, Deniz & Çinar, Melih Ertan, 2020, The diversity of the genus Aricidea (Polychaeta: Paraonidae) from the Sea of Marmara, with descriptions of two new species and two new records for the Mediterranean fauna, pp. 1-73 in Zootaxa 4844 (1) on pages 5-8, DOI: 10.11646/zootaxa.4844.1.1, http://zenodo.org/record/4405867