Lindaspio sebastiena, Bellan & Dauvin & Laubier, 2003

Bellan, Gérard, Dauvin, Jean-Claude & Laubier, Lucien, 2003, The genus Lindaspio (Annelida: Polychaeta: Spionidae), and a new species from an oil field off Congo, western Africa, Journal of Natural History 37 (20), pp. 2413-2424 : 2414-2415

Lindaspio sebastiena n. sp.

(figures 1–6)

Material examined

HOLOTYPE: MNHN UE 854 , incomplete individual, length 30 mm, width 4 mm in the anterior part, 92 setigers.

PARATYPES: MNHN UE 855 , three incomplete individuals: (1) length 33 mm, width 2 mm in the anterior part, 140 setigers; (2) length 45 mm, width 3 mm, 180 setigers; (3) length 50 mm, width 3 mm in the anterior part, 160 setigers .

Two specimens prepared for SEM examination (in the collection of G.B. at Station marine d’Endoume, Marseilles).

Description

Colour in alcohol: pale yellow. Prostomium anteriorly bilobed, partly hidden by two large short conical palps; caruncle absent, palps tapering to pointed tip, not extending beyond setiger 3 (figure 1). Setiger 1 reduced to small neuropodial lobe in lateral position. Notopodial lamellae of second setigerous segment marginally rounded. Neuropodial lamellae subquadrate, larger than notopodial lamellae in anterior setigers. Notopodia and neuropodia of setigers 2, 3 and 4 slightly larger than those of following setigers. Notopodia of setigers 2, 3 and 4 shifted dorsally to medial position. Notopodia of setigers 5–8 gradually shifted to lateral position. Notopodia and neuropodia with presetal lobes well developed in middle and posterior setigers. Dorsal branchiae appear from the setiger 2 and remaining short to setiger 30. Further on, their length increases, exceeding animal width. Neuropodial branchiae absent in the anterior part. From setiger 30 small neuropodial expansion, becoming well-developed neuropodial branchiae by setiger 40. From setiger 40 to end of all fragments, noto- and neuropodial branchiae of same length and shape (figures 2a, 3a). These elongated branchiae, in particular notopodial ones, covered with thick felting (figure 3b–d), possibly caused by an accumulation of polypeptides and retaining silt and other sediment detritus. Felting simple but firmly pasted along interior part of cirri. All neuropodia bear capillary setae. First notopodium lacks setae. Notopodia 2, 3, 4 bearing around 20 heavy projecting acicular spines, arranged in three horizontal rows (figure 4). Spines of posterior row larger, longer than those of other two rows. From parapodium 5, notopodial setae are all capillaries. From parapodium 55 and posteriorly, two notopodial hooded hooks appear (figure 2b), together with six smaller, more delicate multidentate neuropodial acicular hooded hooks (figures 2c, 5). Hooded hooks with several minute teeth above main fang. From setiger 60, there are four to five notopodial and 10 neuropodial acicular setae. In middle and posterior neuropodia, long special, spiny splintered setae present, larger than usual capillary setae, and easily detectable. Their end is abruptly bent, then sinuous, with their hirsute surface covered with minute spinelets (figure 6). Posterior end of body and pygidium unknown.

Etymology. The species is named for Sebastien Amouroux.

Ecology. Lindaspio sebastiena n. sp. was collected in the N’Kossa ( Republic of Congo) oil field. Sediment is a muddy (30% silt) coarse sand (41% sand) containing a large amount of organic carbon (2.4%), barium (5210 ppm) and hydrocarbons (4680 ppm). These three pollutants come from the oil-field drilling. More important species of the community are, with L. sebastiena , Capitella cf. capitata (Fabricius, 1780) , Ophiodromus berrisfordi Day, 1967 and a new Vesicomyidae (von Cosel and Salas, in preparation).