Pista mediterranea Gaillande, 1970

Lavesque, Nicolas, Daffe, Guillemine, Londoño-Mesa, Mario H. & Hutchings, Pat, 2021, Revision of the French Terebellidae sensu stricto (Annelida, Terebelliformia), with descriptions of nine new species, Zootaxa 5038 (1), pp. 1-63 : 42-44

Pista mediterranea Gaillande, 1970

Figure 19

Pista mediterranea Gaillande 1970: 443–448 , figs 1–7.

Synonym. Pista malmgreni Saphronova & Jirkov in Jirkov, 2001

Material examined. Holotype (examined by M.H. L-M): USNM 42795 , Port Miou , near Marseille, S. France, Mediterranean Sea, depth 2.5 m, January 1969 . Paratype MNHN-IA-TYPE0819 (10 posteriorly incomplete specimens), Mediterranean Sea , Cassis, Port Miou, approx. 43°12’29”N 5°31’05”E, depth 2.5 m, January 1969 .

Additional type material. Paratypes USNM 42796 , seven specimens. Not examined .

Description (based on paratype MNHN-IA-TYPE0819). Relatively large species, all specimens posteriorly incomplete, with longest specimen being 39.1 mm long and 2.6 mm wide.

Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part of prostomium shelf-like. Buccal tentacles long, filiform, deeply grooved. Peristomium forming lips, upper lip hood-like, large, wider than long, convoluted; lower lip swollen and squared shaped ( Fig. 19C ).

Segment I partially covered by lateral lobes of SG II, with small ventral lobes, projecting anteriorly ( Fig. 19 A–B ), connected to each other by a smooth membrane with rounded ventral indentation, surrounding lower lip. Segment II with pair of rounded ventro-lateral lobes, connected to each other by a large mid-ventral crest, indented and crenulated ventrally. Segment III with pair of developed lateral lobes, larger than those of SG II, auricular-shape, connected to each other by a thin mid-ventral crest, ventrally crenulated. Segment IV with pair of small latero-dorsal rounded lobes ( Fig. 19A–B ).

Dorsal anterior margins of SG III-XI as protruding crests ( Fig. 19D ). Two pairs of dorso-lateral arborescent branchiae present on SG II–III, second pair slightly smaller, first pair inserted more dorsally; each branchia with long, annulated basal stem, branches arranged in spiral and highly dichotomous, with long filaments ( Fig. 19A–D ). Smooth mid-ventral shields present on SG –XXI, rectangular, of uniform width anteriorly, and becoming progressively longer posteriorly ( Fig. 19C ).

Notopodia beginning on SG IV, extending until SG XX; notopodia short, rectangular, first four pairs inserted progressively more laterally, then longitudinally aligned ( Fig. 19A–B, D ). Broadly-winged notochaetae arranged in two rows, broader on one side, with first row shorter (see Gaillande 1970: fig. 3).

Neuropodia present from SG V, as low, almost sessile ridges until end of notopodia, as low rectangular pinnules thereafter ( Fig. 19A–C ). Neurochaetae as long-handled uncini on SG V–X, with well-developed handles originating from heel, becoming progressively shorter; uncini arranged in partially intercalated double rows on SG XI–XX, in a face-to-face arrangement. Uncini from SG V very high, with a vertical prow ( Fig. 19E–F ). Uncini of following segments with the typical shape (i.e. normal size) ( Fig. 19G ); uncini with distally rounded prow with a comma-shaped extension, rounded heel, conspicuous dorsal button inserted halfway between base of main fang and prow, and main fang surmounted by a crest with five rows of numerous and progressively shorter secondary teeth.

Genital papillae on SG VI–VII, situated dorsally behind notopodia.

Pygidium not known.

Type locality. France, Western Mediterranean Sea , Cassis (Port Miou). Approx. 43°12’29”N 5°31’05”E .

Distribution. Mediterranean Sea ( Gaillande 1970, Jirkov & Leontovitch 2017).

Habitat. Mud, in Lithophyllum algae ( Gaillande 1970), shallow water, depth 2–4 m ( Gaillande 1970, Jirkov & Leontovitch 2017).

Remarks. In the original description, Gaillande (1970) wrote that the long-handled processes of the uncini were difficult to see from SG VII to SG X, but we are able to observe these processes, which are thinner than in the previous chaetigers but clearly visible ( Fig. 19G ).

Pista malmgreni Saphronova & Jirkov in Jirkov, 2001 was synonymised with P. mediterranea by its own authors (Jirkov & Leontovitch 2013). When they described this species, whose type locality is situated in Bahuslän (Western Sweden), the authors also used a paratype from the Mediterranean Sea (Marseille) ( Gil 2011). Further investigations based on holotype should be conducted to confirm this synonymy or to reinstate P. malmgreni .

Figures

FIGURE 19. Pista mediterranea Gaillande 1970 Paratype MNHN-IA-TYPE0819.A. Entire specimen, lateral view; B.Anterior end, ventral view; C. Anterior end, ventral view; D.Anterior end, dorsal view; E–F. Uncini, SG V; G. Uncinus, SG X.Abbreviations: Br, branchiae; Dc, dorsal crests; Gp, genital papilla; Ll, lower lip; Ul, upper lip. Numbers referring to segments; black arrows pointing to comma-shaped extension.