Lumbrineris lusitanica, Martins, Roberto, Carrera-Parra, Luis F., Quintino, Victor & Rodrigues, Ana Maria, 2012

Martins, Roberto, Carrera-Parra, Luis F., Quintino, Victor & Rodrigues, Ana Maria, 2012, Lumbrineridae (Polychaeta) from the Portuguese continental shelf (NE Atlantic) with the description of four new species, Zootaxa 3416, pp. 1-21 : 13

Lumbrineris lusitanica sp. nov.

Figure 4

Material examined. Type material: Holotype ( MNHN TYPE 1540) northwestern Portuguese continental shelf, site R16, 41º27.557ʹ N 8º51.866ʹ W, October 2007, in fine sand, 52.3 m. Paratypes: MB29-000230, 2 specimens, same data as holotype. MB29-000231, 2 specimens, site PC114. MB29-000232, 6 specimens, site PC118. MB29- 0 0 0 233, 1 specimen, site PC119. ECOSUR0130, 2 specimens, site R25. DBUA 0 1316.01, 2 specimens, site PC118. DBUA 0 1316.02, 1 specimen, site PC119. Additional material: site G18(1), 27 specimens; site G26(1), 6 specimens; site R16, 18 specimens; site R19, 5 specimens; site R25, 4 specimens; site PC114, 4 specimens; site PC118, 29 specimens; site PC146, 1 specimen; site PC173, 1 specimen; site PC180, 21 specimens; site PC187, 32 specimens; site PC195, 26 specimens.

Description. Holotype complete with 174 chaetigers, LT= 33.5 mm, L10= 2.5 mm, W10= 0.7 mm. Prostomium conical, slightly longer than wide, with a pair of nuchal organs, short buccal lips ventrally. Peristomium shorter than prostomium, about half its length, with two rings of similar size ( Fig. 4 A).

All parapodia well developed, first six smaller than following ones. Prechaetal lobe in parapodia 1–4 inconspicuous; from parapodia 5 very short, as a globular projection, gradually increasing in length between parapodia 6–15; from parapodia 16 as a digitiform lobe, always smaller than postchaetal lobe. Postchaetal lobe in parapodia 1 small and conical; in parapodia 2–48 digitiform wide basally; becoming longer in posterior parapodia ( Fig. 4 B–D). Short rounded dorsal cirri in all parapodia.

Composite multidentate hooded hooks in chaetigers 1–11, 2–3 per chaetiger, with short blade, with up to 7 teeth, proximal tooth largest ( Fig. 4 E). Simple multidentate hooded hooks from chaetiger 11, with short hood, with up to 7 teeth, preacicular hook twice as big as postacicular hook, proximal tooth largest ( Fig. 4 F). Dorsal limbate chaetae in chaetigers 1–38, ventral limbate chaetae in chaetigers 1-11. Aciculae yellow, aristate, one in anterior parapodia and up to two in the posterior parapodia.

Pygidium with terminal anus, with two pairs of anal cirri, dorsal longer than ventral pair.

Mandible divided for about half its length. Maxillary apparatus with five pairs of maxillae; maxillary carriers as long as MI, anterior end constricted. MI forceps-like with attachment lamella well developed. MII as long as MI, with wide connecting plates slightly developed; with four teeth of similar size. MIII unidentate, followed by a knob, with a very prominent projection in the basal part of the maxilla. MIV unidentate, with a pointed tooth. MV free, prominent, lateral to MIV and MIII ( Fig. 4 G).

Variations. The material examined ranged in L10 from 1.4 to 3.2 mm, in W10 from 0.3 to 0.9 mm and varied in the following features: the last composite multidentate hooded hook was found from chaetigers 7 to 15; the first simple multidentate hooded hook was found from chaetigers 8 to 16; the last ventral limbate ranged from chaetiger 8 to 17 and the last dorsal limbate from 25 to 59 (cf. Table 2).

Reproduction. Mature specimens were found only in October. Male gametes of Lumbrineris lusitanica sp. nov. (Paratypes MB29-000231, DBUA 01316.02) were located from chaetiger 35 to 139, and had a long tail and head with a subspherical form, with diameters ranging from 2.8 to 3.2 µm. Female gametes (Paratypes MB29- 0 0 0 232, DBUA 01316.01) were located from parapodia 34 though the last segment of an incomplete specimen. The gametes were globular with a size diameter ranging between 181 and 192 µm.

Distribution and habitat. Lumbrineris lusitanica sp. nov. is widely distributed on the whole Portuguese continental shelf, at water depths ranging from 14 to 190 m, but mostly below 100 m (cf. Table 3 ). The species is recorded in mud as well as in fine gravel however, it is usually found in fine and very fine sands with low to moderate fines content. Overall, the sediments are characterized by very high sand content and low to moderate content in fines, gravel, biogenic fraction and TOM (averages of 77.5%, 15.4%, 7.1%, 3.8% and 2.6%, respectively) (cf. Table 3 ).

Type locality. Northwestern and western Portuguese continental shelf.

Etymology. The specific name lusitanica refers to the western Iberian Roman province, where this species is very dominant.

Discussion. Lumbrineris lusitanica sp. nov. is characterized by having an unidentate MIII, followed by a knob. According to Carrera-Parra (2006b) the following species have this kind of MIII: L. amboinensis Grube (from Amboina and Kai Islands), L. grandis Treadwell (from Hawaii), L. futilis (from North Sea) and L. reunionensis Carrera-Parra (from La Reunion and Amsterdam Islands). Lumbrineris lusitanica sp. nov. differs from this group of species by having yellow aciculae, while they are black or dark red in all the other. Lumbrineris lusitanica sp. nov. differs from L. reunionensis by having the postchaetal lobe digitiform wide basally in anterior parapodia and digitiform in posterior ones, while L. reunionensis has a conical postchaetal lobe throughout the body; furthermore L. lusitanica sp. nov. has MIV as a pointed tooth, while L. reunionensis has a well-developed plate. Moreover, L. lusitanica sp. nov. differs from L. futilis and L. reunionensis by having composite multidentate hooded hooks with short rather than long blade.

Figures

FIGURE 4. Lumbrineris lusitanica sp. nov. Paratype (ECOSUR 0130) A, anterior end, dorsal view; B, parapodium 3, frontal view; C, parapodium 13, frontal view; D, parapodium 79, frontal view; E, composite multidentate hooded hook, from parapodium 3; F, simple multidentate hooded hooks, from parapodium 79; G, maxillae III and IV, dorsal view. Scale bars: A, 0.7 mm; B, C, D, G 0.05 mm; E, F, 0.025 mm.