Gallardoneris nonatoi (Ramos, 1976) comb. nov.

Figs 1, 2, 3, 4, 5

Lumbrineris nonatoi Ramos, 1976: 124-127, figs 19-21 - Campoy (1982): 605-606; Papadopoulou et al. (1994): 263; Gil (2011): 398.

Gallardoneris iberica Martins, Carrera-Parra, Quintino & Rodrigues, 2012: 6-10, fig. 2 - Bertasi et al. (2014): 3-5, figs 2-4; D’Alessandro et al. (2016): 236-237, fig. 4; García Gómez et al. (2016): 1430-1432, fig. 3A; Katsiaras et al. (2018): 1611-1614, figs 2-3. [Syn. nov].

Material examined.

Western Mediterranean Sea. CEAB AP 986A, 3 specimens, Gulf of Fos, France, approx. 43.41°N, 04.93°E, 2008, coll. Creocean ; CEAB AP 986B, 2 specimens, Gulf of Fos, France, approx. 43.41°N, 04.93°E, 2009, coll. Creocean ; CEAB AP 986C, 30 specimens, Quai de Sete, France, approx. 43.40°N, 3.72°E, 2009, coll. Creocean ; CEAB AP 986D, 5 specimens, Port la Nouvelle, France, approx. 43.01°N, 03.08°E, 2010, coll. Creocean. All specimens fixed with a 10% formalin/sea water solution, stained with Rose Bengal and preserved in 70% ethanol.

Additional material.

Gallardoneris iberica: 1 paratype (DBUA0001315.01), preserved in 96% ethanol, NW continental shelf of Portugal, Atlantic Ocean, 39°48.584'N, 09°13.773'W, 100.5 m, fine sand, MeshAtlantic St. 3B, coll. R. Martins, June 2010 ; 3 non-type specimens (DBUA0001457.01), preserved in 70% ethanol, off Barcelona, Catalonia, Spain, western Mediterranean Sea, 41°23'27.14"N, 02°12'56.58"E, 21 m, muddy sand, coll. S. García Gómez, October 2013 .

Description.

Prostomium conical, variable, short, almost equally longer than wide, lacking antennae and eyes; peristomium shorter and clearly wider than prostomium, with two rings of similar size; junction of prostomium with peristomium normally forming an open angle (Figs 1A, 2A, B, D, E). Maxillary apparatus with four pairs of maxillae; maxillary carriers as long as maxillae I (MI), almost triangular, joined along base of MI; MI forceps-like with wide recurved base, without attachment lamella; MII stout, as long as MI, with ligament, with three teeth, without attachment lamella; MIII edentate; MIV edentate plate, with lighter central area (Fig. 1B). Mandible completely fused, Y-shaped. Prechaetal lobe inconspicuous in most anterior chaetigers, becoming ovoid and longer along body until being clearly digitiform and longer than postchaetal lobe in most posterior chaetigers; postchaetal lobe auricular in anterior segments, becoming digitiform from ca. chaetiger 20 (Fig. 1C). Bilimbate capillary chaetae from chaetiger 1 to 7-12 dorsally and from 1 to 24-30 ventrally, with limb typically forming a clearly asymmetrical basal swelling, tapering swiftly to a slender and long tip curving smoothly but clearly on same side of basal swelling. Composite multidentate hooded hooks up to chaetiger 9 (ranging from 4-12, Fig. 4A), with very short blades, 6-8 teeth either all similar or with proximal tooth bigger (due to partial fusion of several smaller teeth) and a long hood, and a characteristic second swelling at shaft end, at shaft/blade joint level (Figs 1D, 3A, B, E, F); replaced from chaetiger 10 by simple multidentate hooded hooks, with seven or eight teeth similar in size, proximal one larger due to partial fusion of several smaller teeth (Figs 1E, 3C, D). Up to four aciculae, yellow, aristate, reducing to one or two in posterior parapodia. Pygidium conical, lacking anal cirri; anus dorsal (Figs 1P, 2C, F).

Type locality.

Gulf of Roses (= Bay of Roses), Catalan Sea (northwestern Mediterranean, 42°15'6"N, 3°9'6"E), 10 m depth, sandy mud (Ramos 1976).

Known distribution.

Western and eastern Mediterranean Sea, Adriatic Sea, Aegean Sea, Levantine Sea; Atlantic coasts of the Iberian Peninsula; on sandy and muddy bottoms; 4-180 m depth.

Morphometry.

Gallardoneris nonatoi comb. nov. is a relatively small species, and the studied population ranged from slightly <5 mm to ~ 17 mm long. This character showed the largest size-related variability (130%), followed by the number of chaetigers with composite hooded hooks (100%) (Table 1, Fig. 4A). The lowest variability occurred in prostomium and peristomium width (slightly <40%), followed by the widths at chaetigers 10 and 15 (between 50% and 60%) (Table 1, Fig. 5B, C, F). However, some characters proved to be significantly size-related (Table 1, Figs 4A, B, 5A-F). The best correlation occurred between prostomium and peristomium width, followed by the number of chaetigers vs. total body length and number of chaetigers with composite hooded hooks vs. total number of chaetigers (Table 1, Figs 4A, 5A, F). The weakest correlation occurred between number of chaetigers with bilimbate chaetae and total number of chaetigers, followed by body width at chaetiger 10 and total body length (Table 1, Figs 4B, 5B). Moreover, this relationship was much weaker than that between body width at chaetiger 15 and total body length (Table 1, Fig. 5B, C), indicating that the latter better represented the total size in case on finding fragmented worms.

Remarks.

All Mediterranean specimens studied fully agree with the original description of the species by Ramos (1976), with minor morphometric and morphological variation, both in composite and simple hooks and parapodial characteristics. Some of them may result from the size-related morphometric relationships described above, but also from differences in observation procedures and drawing interpretations (Tables 1, 2, Figs 1B-O, 3A-F, 4A, B, 5A-F).

Gallardoneris nonatoi comb. nov. characteristically lacks anal cirri, a feature seldom observed among lumbrinerids. They are also absent in members of Lumbrinerides and Lumbrineriopsis, two genera that also coincide in lacking MV. However, these two genera form a cohesive group sharing other characters that are absent in Gallardoneris, including having bidentate simple hooded hooks, lacking composite hooks, or having completely pigmented MIV (Carrera-Parra 2006a). The lack of anal cirri in G. nonatoi comb. nov. in relation to Lumbrinerides / Lumbrineriopsis would thus be due to homoplasy. However, as the posterior region of the other species in the genus has not been fully described, it is not possible to state definitely if it is a valid generic diagnostic character.

According to Ramos (1976), the holotype of L. nonatoi was deposited in the collections of the Muséum National d’Histoire Naturelle of Paris (MNHN). However, it is not referred in the MNHN catalogue of polychaete types by Solís-Weiss et al. (2004), neither was it possible to locate it in this museum or in any other collection according to Carrera-Parra (2006b). However, we do not consider it necessary to designate a neotype, as the holotype might still exist in the MNHN collections, being just misplaced or mislabelled. Moreover, this taxon is clearly defined and there is no obvious exceptional need for a neotype designation, in accordance to article 75.1 of the ICZN (International Commission on Zoological Nomenclature 1999).