Leodice laurillardi ( Quatrefages, 1866 )

Arias, Andrés, Fernández-Álvarez, Fernando Á., Martins, Roberto & Anadón, Nuria, 2015, Rediscovery and redescription of Leodice laurillardi (Quatrefages, 1866) comb. nov. (Annelida: Eunicidae) — a rare European polychaete or just an overlooked species?, Zootaxa 3964 (4), pp. 475-481 : 476-481

Leodice laurillardi ( Quatrefages, 1866) , combinatio nova

Figures 1–3

Eunice laurillardi Quatrefages, 1866: 314 –315; Grube 1870: 294; Fauchald 1992: 190 –192.

Eunice torquata (non Quatrefages, 1866).— Pruvot & Racovitza 1895 (in part); Fauvel 1923 (in part); Campoy 1982 (in part).

Material examined. Type material. Nice, Provence Region, France, 1868 (deposit date), 1 syntype ( MNHN TYPE 419); Palermo, Sicily Island, Italy, 1868 (deposit date), 1 syntype ( MNHN TYPE 420); 1 syntype ( MNHN TYPE 456) NOT E. laurillardi see Remarks below. Non type specimens. L’Arbellal cove, Gijón, Asturias, Spain, Coll. April 2011, 1 specimen ( MNCN 16.01/16510); Santander Bay, Spain, specimens Num. 674 from the Rioja Collection, 1894–1917 (in part), 1 specimen ( MNCN 16.01/14708).

Comparative material. Leodice torquata . Saint-Jean-de-Luz, Aquitaine, France, Coll. August 2012, 3 specimens ( MNCN 16.01/16511); Aramar, Luanco, Asturias, Spain, Coll. March 2000, 2 specimens ( MNCN 16.01/16512).

Diagnosis. Prostomium shorter than peristomium; prostomial appendages in crescent pattern. Palps reaching chaetiger 1, lateral antennae and median antenna reaching chaetiger 2−4, all with basal ring-shaped ceratophore; palpostyles and ceratostyles with regular cylindrical articulation drop-shaped distally. Peristomium with first ring four to five times longer than second ring. Peristomial cirri with articulation, reaching anterior margin of first peristomial ring. Branchiae from chaetiger 2−3 to almost end of body, with maximum of eight to ten filaments in pectinate arrangement. Bidentate compound falcigers with falcate hoods. Heterodont pectinate chaetae with 11−15 slender teeth. Aciculae dark brown, paler in anteriormost chaetigers, two per parapodium. Bidentate, dark brown, single subacicular hooks from chaetiger 29−32, with both teeth of similar size. Pygidium with articulated anal cirri.

Description. Based on syntypes with variation of Spanish specimens included. Complete specimens with about 190 chaetigers, larger specimen 152 mm long, 4.5 mm wide at chaetiger 10 (without parapodia). Body cylindrical, slightly compressed dorsoventrally in posterior region. Live specimens with uniform bright orange colour without a lighter ring on anterior segments; ethanol stored specimens uniform cream coloured with iridescence still present ( Fig. 1 A, B). Prostomium clearly shorter and narrower than peristomium ( Figs 1 A, B, 2A); prostomial lobes frontally rounded, dorsally swollen. Prostomial appendages in crescent pattern (Figs, 1A, 2B). Palps reaching chaetiger 1, lateral antennae and medial antenna almost equal in length reaching chaetiger 2−4; palps and antennae with basal ring-shaped ceratophore; palpostyles and ceratostyles regularly articulated with cylindrical articulation drop-shaped distally and with up to 14 articulations in median antenna ( Figs 1 A, B, 2A). Dark pigmented rounded eyes between bases of palps and lateral antennae. Peristomium with first ring four to five times longer than second ring ( Figs 1 A, B, 2A). Peristomial cirri with 6−9 articulations, overpassing anterior margin of first peristomial ring, inserted distally on second peristomial ring, slightly lateral to lateral antennae ( Fig. 1 A, B). Branchiae from chaetiger 2−3 to almost end of body, first branchia single ( Figs 2 A, B, 3A), bifid or with up to five filaments always shorter than articulated dorsal cirri (usually with asymmetry between right and left parapodium), then number of filaments increasing rapidly to maximum of eight to ten in pectinate arrangement over chaetiger 20 ( Figs 2 C, 3B); by chaetiger 50−60 diminishing in number and becoming smaller ( Fig. 3 C, D) and being simple again in posterior chaetigers. Prechaetal and postchaetal lobes low with transverse folds. Anterior ventral cirri thick and ovoid-shaped ( Figs 2 B, 3A) becoming basally inflated from chaetigers 8−10 to medial chaetigers ( Fig. 3 C), posterior ventral cirri elongated with smaller base ( Fig. 3 D).

Anterior chaetigers with following chaetal complement from superior to inferior part of chaetal fan: two to eight slender limbate chaetae, four to eight pectinate chaetae ( Fig. 1 I), two protruding distal tips of aciculae ( Figs 2 J, 3F) and four to eight bidentate compound falcigers marginally coarsely serrated, internally striated with falcate hoods ( Figs 2 F, I, 3E). Pectinate chaetae, flat with 9−15 slender teeth with a lateral tooth longer than others (heterodont) ( Fig. 2 G, H). Aciculae dark brown with tapering distal ends, lighter in anteriormost parapodia and darker and slightly curved in medial and posterior ones, two per parapodium ( Figs 2 J, 3F). Bidentate dark brown subacicular hooks from chaetiger 29−32 with both teeth of almost similar size, always single ( Figs 2 E, 3G). Pygidium with two pairs of anal cirri, dorsal pair as long as last five chaetigers with up to five cylindrical articulations ( Fig. 2 D), ventral pair reduced to small bump. Maxillary formula (based on syntype MNHN TYPE 420 with variation of Santander specimen included in brackets): Mx I 1 +1; Mx II 6 +6 (5+6); Mx III 6 +0 (8+0); Mx IV 5 +8 (7+10); Mx V 1 +1; Mx III part of distal arc ( Fig. 1 C).

Remarks. One syntype (MNHN TYPE 456) is actually a species of the genus Arabella , a member of the family Oenonidae . Fauchald (1992) in his revision of the genus Eunice listed another syntype from Marseille (MNHN Paris A.1 (R.)-1868-no. 49a) consisting of a posterior fragment, but currently this specimen is not extant among the vouchers of the MNHN (T. Meziane pers. comm.). One preserved specimen from the E. Rioja Collection (Num. 674) found in a little vial within a larger container with several specimens labelled as Eunice florideana from Santander Bay was re-examined and transferred to L. laurillardi .

Leodice laurillardi was synonymised with L. torquata by Pruvot & Racovitza (1895) on the basis of observations made by Grube (1870). This author pointed out that among the type specimens of L. laurillardi he found two specimens that he considered as Eunice vittata and another two that he was not able to differentiate from L. torquata . Also, Grube (1980) highlighted some inconsistences among the specimens and the original species description related to the shape of prostomium. Later, Fauvel (1923) adopted this synonymy and subsequently it was widely accepted among polychaetologists (e.g. Campoy 1982) and the species remained as such until Fauchald (1992) in his worldwide revision recognised the species as valid.

Leodice laurillardi and L. torquata appear very similar in preserved condition and share a number of diagnostic parapodial and chaetal characteristics. It is not surprising that they have been confused on the basis of stored material ( Grube 1870; Pruvot & Racovitza 1895). However, the two species can be differentiated in that L. torquata is a much larger, more robust species than L. laurillardi . Their colour patterns are strikingly different, L. torquata has a red-brownish colouration with white spots dorsally and laterally in medial and posterior segments, a characteristic whitish ring in the fourth chaetiger and white-striped palps, antennae, peristomial and dorsal cirri; in contrast L. laurillardi has a uniform bright orange colouration without spots nor a whitish ring on anterior segments. Other differences are related to the length of antennae, shorter in L. torquata and the arrangement of the subacicular hooks, always single in L. laurillardi and usually paired in L. torquata (in medial and posterior regions).

Habitat and distribution. Leodice laurillardi is known from the littoral shores of the eastern and central Mediterranean ( Quatrefages 1866) and northeastern Atlantic Ocean, southern Bay of Biscay, being reported in an intertidal-shallow subtidal rocky-shore community. Furthermore, L. laurillardi constitutes a new record for the Iberian Peninsula fauna and for the Eastern Atlantic waters, making the southern Bay of Biscay its northernmost known distribution to date.

However, we expect that L. laurillardi is more widely distributed among the Mediterranean Sea and the Atlantic Iberia and has at times been misidentified as L. torquata . A detailed and widespread sampling campaign and re-examination of museum holdings would be required in order to ascertain the real distribution of this species in Europe.

Figures

FIGURE 1. Leodice laurillardi (MNHN TYPE 419). Syntype A, B. A, detailed view of the prostomium and peristomium; B, anterior end, lateral view; C, detailed view of the maxillary apparatus. L, left side; Mb, mandibles; Mx, maxilla; R, right side.

FIGURE 2. Eunice laurillardi. Scanning electron micrographs. A, anterior end, lateral view; B, detailed view of parapodium chaetiger 2 and 3; C, median chaetigers, lateral view; D, enlarged view of pygidium showing the anal cirri; E, detailed view of subacicular hook of parapodium chaetiger 30; F, detailed view of bidentate compound falciger of parapodium chaetiger 2; G, detailed view of pectinate chaeta of parapodium chaetiger 2; H, bundle of pectinate chaetae of parapodium chaetiger 6; I, bidentate compound falciger of parapodium chaetiger 40; J, detailed view of the aciculae of parapodium chaetiger 10.

FIGURE 3. Leodice laurillardi. A, parapodium chaetiger 2; B, detailed view of branchia from chaetiger 30; C, parapodium chaetiger 60; D, parapodium chaetiger 150; E, bidentate compound falciger of parapodium chaetiger 2; F, aciculae of parapodium chaetiger 60; G, subacicular hook of parapodium chaetiger 60.