Terebella banksyi, 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 : 50-53

Terebella banksyi n. sp.

Figures 23–24

Material examined. Holotype. MNHN-IA-TYPE 2037, complete in two parts, gravid, Northeastern Atlantic , Bay of Biscay , Arcachon Bay, Grand Banc, approx. 44°40’27”N 01°11’46”W, intertidal, October 2017, few parapodia used for molecular analysis . Paratypes. AM W.53332, complete, Northeastern Atlantic , Bay of Biscay , Arcachon Bay , Jacquets , 44°43’17”N 01°11’24”W, intertidal, in oyster reefs, January 2018. MNHN-IA-TYPE 2038, complete, Northeastern Atlantic , Bay of Biscay , Arcachon Bay , Le Cla, 44°40’43”N 01°08’11”W, intertidal, in oyster reefs, August 2017. MNHN-IA-TYPE 2039, Northeastern Atlantic , Bay of Biscay, Arcachon Bay, Jacquets, 44°43’17”N 01°11’24”W, intertidal, in oyster reefs, January 2018, mounted for SEM.

Additional material. SMA-Arc-Eupoly-Jac02, Northeastern Atlantic , Bay of Biscay , Arcachon Bay , Jacquets , 44°43’17”N 01°11’24”W, intertidal, in oyster reefs, January 2018, mounted for SEM. SMA-Arc-Terebella-02, one specimen, complete, Northeastern Atlantic Ocean , Arcachon Bay , Le Cla, 44°40’43”N 01°08’11”W, intertidal, in oyster reefs, August 2017, some parapodia used for molecular analysis. SMA-Arc-Terebella-03, one specimen, complete, Northeastern Atlantic Ocean, Arcachon Bay, Le Cla, 44°40’43”N 01°08’11”W, intertidal, in oyster reefs, August 2017, some parapodia used for molecular analysis .

Description. Holotype complete, 33.9 mm long (12.1 mm) long and 2 mm wide (0.6 mm), for about 80 segments.

Transverse prostomium attached to dorsal surface of upper lip; basal part with few red eyespots (absent on holotype, probably faded), well separated and situated laterally only; distal part shelf-like. Numerous long and deeply grooved buccal tentacles, reaching end of the body ( Fig. 23A–D ). Peristomium forming lips, upper lip hood-like and slightly convoluted, higher than broad; lower lip swollen, cushion-like, broader than high ( Figs 23B–C , 24B ).

Segment I narrow, forming ventral lobe ( Fig. 23B–C ); absence of lateral lobes on anterior SG I–IV. Three pairs of dichotomous branchiae, on discontinuous segments, SG II–III and V ( Figs 23C–D ; 24A ), with wide medial gap; first pair situated laterally, third pair more dorsally; with numerous short filaments, arising from long stems and branches ( Figs 23A, C–D ; 24A–B ). Dorsum of anterior chaetigers tessellated. Ventral shields on SG II–XIV (n=13), rectangular, well defined, inflated on SG III–IV, absence of mid-ventral groove posteriorly.

Notopodia beginning on SG IV, extending posteriorly until last few chaetigers (n>75); notopodia short, rectangular; decreasing in size posteriorly ( Fig. 23A–D ). Notochaetae identical on all segments, narrowly-winged from mid-length, with blade at an angle of about 45° with the shaft and curled serrated tip ( Fig. 23E–F ).

Neuropodia present from SG V, as low, almost sessile ridges throughout ( Figs 23A–D ; 24B ). Neurochaetae as short-handled avicular uncini, arranged in double rows from SG XI to posterior body, in face-to-face arrangement. Uncini with triangular heel; long digitiform prow, pointing downwards and prolonged by a thin curved tendon, pointed dorsal button inserted halfway between base of main fang and prow, convex base, and main fang surmount- ed by crest with four rows of secondary teeth ( Figs 23G ; 24C–D ).

Twelve pairs of nephridial and genital papillae, a large globular one on SG III at base of branchiae, and small globular ones on SG V–XV, situated between notopodia and neuropodia and slightly displaced posteriorly ( Fig. 23C–D ).

Pygidium rounded.

Etymology. This species is dedicated to Banksy, a brilliant street artist whose graphic work always conveys powerful messages.

Type locality. Jacquets , Arcachon Bay , Bay of Biscay, Northeastern Atlantic Ocean, France, 44°43’17”N 01°11’24”W .

Distribution. Only known from type locality.

Habitat. Under oyster shells, on oyster farms, intertidal.

Remarks. Until now, a single species of Terebella was considered to be valid in the European waters, T. lapidaria Linnaeus, 1767 described from the Mediterranean Sea. Terebella banksyi n. sp. differs from T. lapidaria by the presence of twelve pairs of nephidrial and genital papillae, instead of the five pairs as in members of T. lapidaria , by the branchiae present on discontinuous segments (SG II–III and V), instead of the more usual distribution of the branchiae on consecutive segments (SG II–IV) for T. lapidaria , and by the absence of a spur on notochaetae from posterior chaetigers (instead of the blades at 90° with the shafts of the posterior notochaetae for T. lapidaria ).

Two other species of Terebella were described from European waters, but are now synonymysed with T. lapidaria : Terebella constrictor Montagu, 1819 and Heterophyselia bosci Quatrefages, 1866 ( Read & Fauchald 2021). As Montagu never deposited his type material, it is impossible to confirm the identity of his species. The description is very sparse but the figure (plate XII, Fig. 1 , Montagu 1819) clearly shows absence of branchiae on SG V, and thus differs from T. banksyi n. sp. For the second species, we have compared our material with the syntype of Heterophyselia bosci (MNHN-IA-TYPE0405) which is in very good condition. With the presence of branchiae on SG II–IV and of nephridial and genital papillae until SG X, this species is very similar with T. lapidaria and we suggest these two species should be synonymized, see below.

Finally, another species was described from Canary Islands, close to European waters: Terebella orotavae ( Langerhans, 1881) . This species differs from T. banksyi n. sp. by the distribution of the branchiae on consecutive segments (SG II–IV) instead of the branchiae not present on consecutive segments (SG II–III and V), by the presence of a single nephridial papillae instead of the presence of twelve pairs of nephridial and genital papillae for T. banksyi n. sp. and by the presence of two types of notochaetae, instead of one as in T. banksyi n. sp.

In Arcachon Bay, Terebella banksyi n. sp. was always found associated with the Japanese oysters Crassostrea gigas Thunberg, 1793 , either on oysters reefs or on oysters farms. Recently, a study showed that a new species of bait worms, Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017 ( Lavesque et al. 2017b), described from Arcachon Bay was actually an exotic undescribed species, which originated from either Japan or China and assumed to have been imported into the Arcachon Bay via oyster transfers ( Lavesque et al. 2020c). The morphology of the Asiatic species of Terebella has therefore been verified to confirm that T. banksyi n. sp. is not an exotic species. Three species belonging to this genus were described from Asia: Terebella copia Hutchings, 1990 from Hong- Kong; Terebella punctata Hessle, 1917 , from Japan; and Terebella sarsii Grube, 1878 from Philippines ( Hutchings et al. 2021a). Terebella copia differs from T. banksyi n. sp. by the consecutive presence of branchiae on SGIII–V, and the presence of one to five nephridial and genital papillae only. Terebella punctata differs from T. banksyi n. sp. by the presence of nephridial and genital papillae until SG XXV and the presence of buccal tentacles covered with rows of small and round brown spots (in specimens preserved in alcohol), but no mention is made concerning the distribution of the branchial segments in the original description. Finally, T. sarsii differs from T. banksyi n. sp. by the presence of 17 pairs of notopodia only (and thus probably does not belong to Terebella genus), instead of more than 75. To conclude, T. banksyi n. sp. differs from all currently described species of Terebella from the Asiatic region and we are confident that it is a native species.

Figures

FIGURE 1. Schematic distribution of the different Terebellidae s.s. species along the French coasts.

FIGURE 23. Terebella banksyi n. sp. holotype MNHN-IA-TYPE 2037. A. Entire specimen, lateral view, MG staining; B. Anterior end, ventral view, MG staining; C. Anterior end, lateral view, MG staining; D. Anterior end, dorso-lateral view; E. Notochaetae, SG X; F. Notochaetae, posterior segments; G. Uncini, SG X. Abbreviations: Br, branchiae; Bt, buccal tentacles; Gp, genital papillae; Ll, lower lip; Ul, upper lip. Numbers referring to segments.

FIGURE 24. Terebella banksyi n. sp. paratype MNHN-IA-TYPE 2039 (A), additional material SMA-MNHN-Arc-Eupoly- Jac02 (B–D). A. Anterior end, dorsal view; B. Anterior end, lateral view; C–D. Uncini, SG V. Abbreviations: Ul, upper lip. Numbers referring to segments.