Paradoneis hirsuta, Sardá & Gil & Taboada & Gili, 2009

Sardá, Rafael, Gil, João, Taboada, Sergi & Gili, Josep Maria, 2009, Polychaete species captured in sediment traps moored in northwestern Mediterranean submarine canyons, Zoological Journal of the Linnean Society 155 (1), pp. 1-21 : 8-11

PARADONEIS HIRSUTA SP. NOV. ( FIG. 3A–F )

Type material: Holotype, complete specimen, about 100 chaetigers, and deposited at CMIMA-CSIC (ST01C22, trap 10; 41 °02′N, 01 °56′E; Nov. 1993). Specimen set aside for SEM analysis and stored on a stub.

Etymology: The species name refers to the hirsute appearance produced by the large and characteristic capillary chaetae.

Diagnosis: Species distinguished by hirsute forked chaetae, and presence of branchiae from chaetiger 5.

Description (based on holotype): Complete specimen. About 0.15-mm wide, and just over 20-mm long, with around 100 chaetigers ( Fig. 3A ). Prostomium short, conical, tapering to a blunt point, fused to achaetigerous peristomium. Prostomial antenna absent. Seven pairs of small, acutely pointed, and ciliated branchiae, beginning on chaetiger 5 ( Fig. 3C ). Branchial length around half that of chaetiger width. Ciliary bands on dorsal part of branchiate body region. Postchaetal lobes: digitiform from chaetiger 3, not decreasing in size on postbranchial chaetigers, and becoming longer in central part of body ( Fig. 3A– C ). Postchaetal lobes on branchiate region, about one third of the length of the branchiae. Postchaetal lobes clearly conspicuous in posterior region ( Fig. 3F ). Neuropodial postchaetal lobes absent. Rounded anal lobe: with three long cirri, all more or less equal in size ( Fig. 3F ). Ciliated rounded annulus on the dorsal part of the pygidium. Both rami of all parapodia contain thick capillary chaetae. All capillary chaetae are extremely long, often longer than 0.5 mm in mid body ( Fig. 3A–D ). Capillary chaetae are hirsute. In anterior part of body, capillary chaetae are grouped into dense fascicles of around 20–30 chaetae. Between one and three notopodial lyrate chaetae are present, beginning posterior to branchial region. Lyrate chaetae with two unequal tines, each tine provided with inner row of spines, and with long hairs basally ( Fig. 3E ). No neuropodial specialized chaetae.

Discussion: The genus Paradoneis currently has 13 valid species and two subspecies. Paradoneis hirsuta sp. nov. is unique in the genus in the combination of having branchiae from chaetiger 5 and lyrate forked chaetae ( Table 4). Paradoneis spinifera ( Hobson, 1972) and Paradoneis drachi Laubier & Ramos, 1974 were described as having branchiae from chaetiger 5 or 6, and 7, respectively, but in both species the modified notochaetae are simple acicular spines, instead of being lyrate. Paradoneis forticirrata ( Strelzov, 1973) , a deep-water species from the Pacific Ocean with modified lyrate chaetae, was described as having branchiae starting at chaetiger 4 or 5, but only one of the paratypes, from shallower water, had this branchial formula. Additionally, P. forticirrata has 15–17 pairs of branchiae and modified notochaetae, starting at chaetiger 4–6, whereas P. hirsuta sp. nov. has only seven pairs of branchiae and modified chaetae, starting after the branchial region. Besides its very long capillary chaetae, which can reach more than 0.5 mm in length, P. hirsuta sp. nov. may also be easily separated from all the other species of Paradoneis with lyrate chaetae by its hispid base. Different numbers of prebranchial chaetigers have been described for the type species of Paradoneis , Paradoneis lyra ( Southern, 1914) from Ballynakill Harbour (Galway, Ireland). Bellan (1965) recorded two specimens from the Western Mediterranean, collected at 450 m, with four and eight prebranchial chaetigers. However, Bellan himself (1965), and later Laubier & Ramos (1974), suggested that those specimens were mutilated, and that some branchiae were missing. Katzmann & Laubier (1975) also described specimens of P. lyra , collected in the Adriatic, with the branchiae starting on chaetiger 5, and numbering between four and seven pairs. However, Mackie (1991), in his redescription of the type species based on the holotype, and also on new material collected in the surrounding areas, clearly stated that P. lyra has branchiae from (-) forked chaetae absent; (+) spines notochaeta present; (++) spines neurochaeta present.

chaetiger 4, numbering between three and 14 pairs, depending on the size of the worm, arguing that in this way the specimens described by Katzmann & Laubier (1975) probably belong to a different species.

FAMILY OPHELIIDAE

Figures

Figure 3. Paradoneis hirsuta sp. nov. A, general view. B, dorsal view of the branchiate region. C, dorsal view of mid-region parapodia. D, long capillary chaetae of both rami of parapodia. E, lyrate chaeta of posterior parapodia. F, pygidium, with three cirri and ciliated dorsal rounded organ. Scale bars: A, 1 mm; D, 500 Mm; B, 300 Mm; C and F, 100 Mm; and E, 10 Mm.