Leodice pellucida ( Kinberg, 1865 ) Souza & Zapff & Christoffersen & Zanol, 2024

Souza, Thaís Kananda Da Silva, Zapff, Luana, Christoffersen, Martin Lindsey & Zanol, Joana, 2024, Taxonomy of Leodice Lamarck, 1818 (Annelida, Eunicidae) from Northeast Brazil (Tropical Southwest Atlantic Ocean) with description of a new species, Zootaxa 5492 (2), pp. 151-175 : 166-168

Leodice pellucida ( Kinberg, 1865) comb. nov.

( Fig. 7 )

Eunice pellucida Kinberg, 1865: 562 .— Fauchald, 1992: 261.

Eunice vittata sensu Hartman, 1948:77 . Not Delle Chiaje, 1828.

Material examined. NON-TYPE material Paraíba State: 23 specimens examined. Two incomplete specimens, station 04 ( POLY-UFPB –2029) ; one complete and one incomplete specimen, station 37 ( POLY-UFPB –2033) ; one complete and one incomplete specimen, station 46 ( POLY-UFPB –2031) ; one incomplete specimen, station 55 ( POLY-UFPB –2030) ; one incomplete specimen, station 62 ( POLY-UFPB –2032) ; one complete and two incomplete specimens, station 86 ( POLY-UFPB –2034 ; POLY-UFPB –2035) ; two incomplete specimens, station 87 ( POLY-UFPB –2036 ; POLY-UFPB –2037) ; one incomplete specimen, station 88 ( POLY-UFPB –2038) ; one complete and eight incomplete specimens, station 93 ( POLY-UFPB –2039 ; POLY-UFPB –2040 ; POLY-UFPB –2041) .

Description. 19 incomplete individuals with 19–83 chaetigers and four complete individuals with 87–109 chaetigers, total length of complete individuals ranging from 20–77 mm; L10 ranging from 4–7.5 mm, W10 without parapodia ranging from 1.5–2.5 mm.

Prostomium bilobed, truncate anteriorly, dorsally inflated, shorter and narrower than peristomium, shallow median groove visible dorsally and ventrally; ventral buccal lips conspicuous ( Fig. 7A, C, D ). Palps and antennae evenly spaced, arranged in a horseshoe shape. Palpophores and ceratophores short and ring-shaped, without articulations. Ceratostyles and palpostyles tapering to slender tips, with moniliform regular articulations, drop-shaped at distal end ( Fig. 7A, C, D ). Median antennae longest and palps shortest; palps with 6–11 articulations, reaching posterior edge of first peristomial ring to second peristomial ring; lateral antennae with 10–22 articulations, reaching chaetiger 2–5; median antenna with 14–29 articulations, reaching chaetiger 5–8. Eyes present, posterior to palps and lateral to lateral antennae.

Peristomium cylindrical, laterally longer than medially; dorsal anterior margin covering base of median antenna; anterior region tapering, following prostomium width closely with conspicuous ventrolateral lips. First peristomial ring about ¾ of peristomium total length, separation between rings visible dorsally and ventrally, not laterally. Peristomial cirri slender, tapering, with 3–6 cylindrical articulations, almost reaching anterior edge of first peristomial ring ( Fig. 7A, D ).

Maxillary formula: 1+1; (5–7)+(6–8); (7–8)+0; (4–8)+(8–11); 1+1. MxI with not extended falcal arch, outer basal edge straight, rectangular, basal inner edge with curve, where posterior region of MxII fits. MxIII partially ventral to MxII, anterior end part of distal arch with left MxIV. Left MxIV with teeth decreasing in size in right portion of plate. MxV wide, with small prominent tooth. MxVI absent. MxIV left fixation lamellae semicircular in shape, tapering to right portion, right semi-circular in shape ( Fig. 7B ).

Branchiae pectinate, present from chaetiger 5 to 26–33, in less than 55% of total number of chaetigers. First branchia with one branchial filament, shorter than notopodial cirri, maximum number of branchial filaments 7–12, reached at chaetigers 12–22. Most branchiae longer than notopodial cirri, branchial filaments longer than notopodial cirri and central axis of branchiae; branchiae decreasing in length and number of branchial filaments along mid region of distribution. Branchial central axis slender, tapering in all branchiae.

All chaetal lobes rounded, with aciculae emerging from dorsal half; all pre- and postchaetal lobes as transverse folds, shorter than chaetal lobes. Notopodial cirri basally inflated, tapering to pointed tips, anterior with 4–6 articulations, median with 3–4, and posterior with 2–3. Ventral cirri longer than chaetal lobes in all chaetigers; slender and digitiform until chaetiger 4–5 after that, cirri basally inflated and tapering to digitiform tips from chaetiger 5–6. Inflated base oval, decreasing in size around chaetiger 19–38, after which digitiform tips are longer than anterior ones.

Limbate chaetae, marginally serrated. Pectinate chaetae flat or slightly curved, with 10–12 teeth, marginal teeth unequal in length, longer and thicker than other teeth. Median and posterior pectinate chaetae with blade wider and more abruptly tapering, teeth longer and thinner than anterior pectinate chaetae ( Fig. 7E, I ). Compound falcigers chaetae bidentate or tridentate; anterior with article tapering from proximal to distal end, marginally serrated, bidentate, proximal tooth triangular directed laterally, shorter than laterally or obliquely directed distal tooth ( Fig. 7F ); median with article longer, more robust and with wider guards than anterior, bidentate, proximal tooth triangular, more robust than in anterior chaetae, both teeth laterally; posterior, articles and guards wider than more anterior, tridentate, proximal tooth larger than distal tooth, directed laterally, more robust than in median chaetae, with minute apically directed oblique tooth, both largest teeth directed laterally ( Fig. 7E, I ). Aciculae yellow, usually paired; anterior aciculae tapered, straight or slightly curved, with blunt or sometimes mucronate tips; median aciculae curved, with bifid tips; posterior aciculae more curved than median, one acicula with bifid tip and tapering to thin point ( Fig. 7E, G, H ). Subacicular hooks yellow tridentate, present from chaetigers 21–27, with guards covering proximal and median teeth ( Fig. 7H ).

Pygidium with two pairs of anal cirri. Dorsal cirri digitiform, regularly articulated, with approximately seven segments. Ventral cirri missing, but visible scar present.

Distribution. Leodice pellucida ( Kinberg, 1865) comb. nov. was described from St. Thomas Island (Caribbean Sea) and it has also been reported associated with Phragmatoma caudata in Veracruz (Gulf of Mexico) (León-González and Díaz-Castañeda 2006). This new record expands the distribution of species to Paraíba State, SW Atlantic Ocean.

Remarks. Hartman (1948) and Fauchald (1992) redescribed the species based on the type specimens. Both redescriptions differ in the presence of articulations in notopodial cirri, which are described as present by Hartman and absent by Fauchald.We have observed in our material that this feature is easily lost in poorly preserved specimens. Thus, the contrast among both redescriptions may be due to the state of preservation of the type specimens almost 50 years later, when Fauchald examined it.

The specimens examined for this study contrast with the redescriptions in having eyes, and tridentate compound falciger chaetae. However, the latter may not have been observed in previous studies because, traditionally, one to few parapodia were examined per specimen, not allowing the full investigation of any variation occurring along the body.

We propose the assignment of Eunice pellucida Kinberg, 1865 to Leodice , based on the presence of three antennae and a pair of palps regularly articulated, yellow tridentate subacicular hooks, and tridentate compound falciger chaetae.

Figures

FIGURE 7. Leodice pellucida comb. nov. POLY-UFPB-2023. A—anterior end, dorsal view; B—maxillae, dorsal view; C—anterior end, ventral view; D—anterior end, lateral view; E—parapodium 105, acicula, pectinate chaetae and compound falcigers; F—parapodium 6, compound falcigers; G—parapodium 80, aciculae, compound falcigers chaetae; H—parapodium 105, acicula, compound falcigers and subacicular hook; I—parapodium 105, compound falcigers and pectinate chaetae.