Pista sauriaui, Lavesque & Daffe & Londoño-Mesa & Hutchings, 2021

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 : 46-49

publication ID	https://doi.org/ 10.11646/zootaxa.5038.1.1
publication LSID	lsid:zoobank.org:pub:1C1E4C7A-2452-47BC-B843-2543135EF780
persistent identifier	https://treatment.plazi.org/id/D369E29B-189B-4DB9-A8B6-4D3E95E689DB
taxon LSID	lsid:zoobank.org:act:D369E29B-189B-4DB9-A8B6-4D3E95E689DB
treatment provided by	Plazi
scientific name	Pista sauriaui
status	sp. nov.

Treatment

Pista sauriaui View in CoL n. sp.

Figures 2D View FIGURE 2 ; 21–22 View FIGURE 21 View FIGURE 22

Material examined. Holotype. MNHN-IA-TYPE 2035, Northeastern Atlantic Ocean, Brittany, Bay of Brest , 48°19’58” N 4°26’59”W, depth 3 m, February 2013 GoogleMaps . Paratypes. MNHN-IA-TYPE 2036, Northeastern Atlantic Ocean, Brittany, Bay of Brest , MF1, 48°18’05” N 4°19’26”W, depth 2 m, January 2016, mounted for SEM GoogleMaps . AM GoogleMaps

W.53331, Northeastern Atlantic Ocean, Brittany, Bay of Brest , 48°18’59”N 4°23’28”W, depth 2.2 m, May 2018, posterior part used for molecular analysis GoogleMaps .

Additional material. SMA-LR_ Pista _01, Northeastern Atlantic Ocean, Brittany, Pertuis Breton , 46°13’53” N 1°22’28”W, depth 2 m, April 2013 GoogleMaps ; SMA-LR_ Pista _02, Northeastern Atlantic Ocean, Brittany, Pertuis Breton , 46°13’53” N 1°22’28”W, depth 2 m, April 2013 GoogleMaps .

Description. Holotype posteriorly incomplete, 21.1 mm long (28.5 mm) long and 2.2 mm wide (1.9 mm), for 25 segments.

Transverse prostomium attached to dorsal surface of upper lip; basal part without eyespots; distal part of prostomium shelf-like. Buccal tentacles deeply grooved ( Fig. 22A–B View FIGURE 22 ). Peristomium forming lips, upper lip hood-like, large, wider than long; lower lip large and swollen, rectangular, wider than long ( Fig. 21A View FIGURE 21 ).

Segment I narrow, with one pair of large lobes directed anteriorly; lobes originating dorso-laterally, at level of first pair of branchiae, partially covered laterally by prostomium; connected to each other by thin and smooth membrane with rounded ventral indentation, surrounding lower lip ( Figs 21A–C View FIGURE 21 ; 22A–B View FIGURE 22 ). Segment II with one pair of rounded ventro-lateral lobes, connected to each other by a large mid-ventral crest, ventrally crenulated. Segment III with one pair of lateral lobes, same size as those of SG II, auricular-shaped, connected ventrally to the corresponding ventral pad. Segment IV with pair of very small latero-dorsal rounded lobes, almost inconspicuous ( Figs 21B–C View FIGURE 21 ; 22A–B View FIGURE 22 ).

Dorsal anterior margins of SG III–VIII as protruding crests ( Fig. 21D View FIGURE 21 ). Two pairs of arborescent branchiae situated dorso-lateral on SG II–III, of about the same size, first pair inserted more dorsally; each branchia with long, annulated basal stem, dichotomously branching for some levels, with long branchial filaments ( Figs 21B–D View FIGURE 21 ; 22A View FIGURE 22 ). Corrugated mid-ventral shields present on SG III–XXIII, rectangular, of uniform width anteriorly, and becoming progressively longer ( Fig. 21A View FIGURE 21 ).

Notopodia from SG IV to SG XX; notopodia short, rectangular, first four pairs inserted progressively more laterally, then longitudinally aligned ( Figs 21B–D View FIGURE 21 ; 22A View FIGURE 22 ). Notochaetae broadly-winged of two sizes, arranged in two rows ( Fig. 21E View FIGURE 21 ), with first row shorter.

Neuropodia present from SG V, as low, almost sessile ridges until end of notopodia ( Figs 21B–C View FIGURE 21 ; 22A View FIGURE 22 ), thereafter as low rectangular pinnules. Neurochaetae as avicular uncini, with well-developed handle on SG V–VII ( Figs 2D View FIGURE 2 ; 21F–G View FIGURE 21 ), uncini without handles from SG VIII ( Fig. 22H View FIGURE 22 ), uncini arranged in partially intercalated double rows on SG XI–XX in a face-to-face arrangement. Uncini with short, triangular heel, rounded prow with a comma-shape extension ( Figs 2D View FIGURE 2 ; 21F–H View FIGURE 21 ), short dorsal button inserted halfway between base of main fang and prow, convex base, and main fang surmounted by a crest with five rows of numerous and progressively shorter secondary teeth above the main fang ( Figs 2D View FIGURE 2 ; 21F–H View FIGURE 21 ; 22C–D View FIGURE 22 ).

Genital papillae on SG VI–VII, situated dorsally behind notopodia ( Fig. 21D View FIGURE 21 ). Pygidium unknown.

Etymology. This species is named after Pierre-Guy Sauriau, benthic ecologist from the Laboratory of La Rochelle who provided some of the studied material and who was the first supervisor of NL. This name was chosen in agreement with Jérôme Jourde (La Rochelle), Jacques Grall and Vincent Le Garrec (IUEM Brest) who worked with Pierre-Guy for a long time.

Habitat. Shallow waters (depth 2–3 m), in maërl (rhodolith) beds and Zostera marina meadows.

Type locality. Bay of Brest , Bay of Biscay, Northeastern Atlantic Ocean, France .

Distribution. Bay of Brest and Pertuis Breton (Biscay of Biscay), 48°19’58” N 4°26’59”W.

Remarks. Pista sauriaui n. sp. belongs to the two-pairs of branchiae group in Pista genus, as well as P. cristata , the type species, P. miosseci n. sp. and P. mediterranea , previously included here. Pista sauriaui n. sp. differs from P. cristata by the presence of anterior comma-shaped extension on thoracic uncini (see P. miosseci n. sp. Remarks) and by the presence of dorsal crests on SG III–VIII (these crests are absent in P. cristata ) (see P. miosseci n. sp. Remarks). Finally, these two species differ by the shape of their lateral lobes: P. sauriaui n. sp. has large ones on SG I and very small ones on SG IV, while P. cristata has short ones on SG I and very large ones on SG IV.

Pista sauriaui n. sp. differs from P. miosseci n. sp. by the presence of anterior comma-shaped extension on thoracic uncini which are absent in P. miosseci n. sp. and by long-handled uncini restricted to the SGV–VII, instead of presence of these long-handled uncini at least until SG X in P. miosseci n. sp. Also, P. sauriaui n. sp. has no eyespots, which are present in P. miosseci n. sp. and has large lateral lobes on SG I, while those of P. miosseci n. sp. are absent. Both species, P. sauriaui n. sp. and P. miosseci n. sp. occur in the same geographical area (Bay of Brest, Brittany), in the same habitat (shallow waters, in maerl beds) and share several morphological features. The use of molecular analysis confirms that they belong to different species but they have probably evolved differently. This study clearly highlights the need of integrative taxonomy, combining molecular approach and careful morphological observation, especially for the species complexes.

Pista sauriaui n. sp. differs from P. wui Saphronova, 1988 (described from British Columbia), both with two pairs of branchiae, by the presence of long-handled uncini restricted to the SGV–VII, instead of presence of these long-handled uncini at least until SG X for P. wui , by the presence of large lobes on SG I (instead of small ones) and very short lateral lobes on SG IV, instead of well-developed ones for P. wui . Finally, P. sauriaui n. sp. has dorsal crests on SG III–VIII which are absent for P. wui (see Remarks P. miosseci n. sp.).

Finally, Pista sauriaui n. sp. differs from P. mediterranea by the absence of very high uncini with vertical prow on SG V and by the presence of long-handled uncini restricted to the SGV–VII, instead of presence of these longhandled uncini at least until SG X in P. mediterranea . Also, Pista sauriaui n. sp. differs also by the presence of large lobes on SG I, which are small for P. mediterranea .