Leodice rubra ( Grube, 1856 )

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 : 168-171

Leodice rubra ( Grube, 1856)

( Fig. 8 )

Eunice rubra Grube, 1856: 59 .

Eunice rubra . — Fauchald, 1992: 290.

Eunice rubra .— Steiner et al. 2002: 243.

Leodice rubra .— Zanol et al. 2014: 90.

Material examined. NON-TYPE material Paraíba State: 21 specimens analyzed. One complete specimen, station 01 ( POLY-UFPB –2055) ; one complete specimen, station 10 ( POLY-UFPB –2062) ; one complete specimen, station 11 ( POLY-UFPB –2063) ; one complete specimen, station 20 ( POLY-UFPB –2064) ; one complete specimen, station 36 ( POLY-UFPB –2060) ; one complete specimen, station 37 ( POLY-UFPB –2061) ; one complete specimen, station 41 ( POLY-UFPB –2059) ; two incomplete specimens, station 43 ( POLY-UFPB –2056) ; one incomplete specimen, station 60 ( POLY-UFPB –2057) ; one complete specimen, station 62 ( POLY-UFPB –2058) ; seven complete specimens, station 67 ( POLY-UFPB –2065 ; POLY-UFPB –2066) ; one complete specimen, station 76 ( POLY-UFPB –2067) ; one complete specimen, station 82 ( POLY-UFPB –2068) ; one complete specimen, station 84 ( POLY-UFPB –2069) .

Description. Three incomplete specimens with 23–57 chaetigers and 18 complete specimens with 84–123 chaetigers; total length of complete specimens ranging from 23 to 70 mm; L10 ranging from 3.5 to 8.0 mm, W10 1.5–2.5 mm, without parapodia.

Prostomium bilobed with deep median groove visible dorsally and ventrally,truncated anteriorly with conspicuous ventral buccal lips, distinctly shorter and narrower than peristomium ( Fig. 8A, B, C ). Prostomial appendages evenly spaced in semicircle; palps anterior to lateral antennae. Palpophores and ceratophores short, ring-shaped, without articulations. Ceratostyles and palpostyles tapering, with moniliform articulations. Median antennae longest and palps shortest; palps reaching middle of first peristomial ring to posterior of second peristomial ring, with 8–14 articulations; lateral antennae reaching middle of first peristomial ring to fourth chaetiger, with 14–24 articulations; median antenna reaching from first to seventh chaetiger, with 18–28 articulations. Pair of eyes present, posterior to palps and lateral to lateral antennae.

Peristomium cylindrical, laterally longer than medially; dorsal anterior margin partially covering bases of median and lateral antennae; anterior half narrower than posterior; with conspicuous ventro-lateral lips. First ring about ¾ of total length; separation between rings visible dorsally and ventrally, but not laterally. Second peristomial ring longest dorsally; longer medially than laterally at ventral side and on dorsal side. Peristomial cirri with 3–5 articulations, basally inflated, tapering distally, reaching anterior edge of first peristomial ring ( Fig. 8A, B ).

Maxillary formula: 1+1; (5–7)+(6–8); (6–8)+0; (5–8)+(7–11); 1+1. MxI without extended falcal arch, basal inner edge with curvature, where most posterior region of MxII fits; MxII with teeth distributed in more than half of its length; MxIII partially ventral to MxII with anterior region part of distal ventral arch to MxIV; MxIV with teeth decreasing in size in right portion of plate; MxV wide with a small tooth ( Fig. 8D ). MxVI absent. MxIV left lamella semi-circular in shape, tapering to right portion, right fixation lamella semi-circular in shape.

Branchiae pectinate, present from chaetigers 5–7 to 75–120, present in more than 65% total number of chaetigers; first branchia with one branchial filament shorter than notopodial cirri, maximum number of branchial filaments 6–17, reached on chaetiger 10–18; branchial filaments longer than notopodial cirri, central axis of branchiae longer than branchial filaments and notopodial cirri; branchial filaments reduced in length and in number in middle of branchial distribution, of 2–3 branchial filaments; and increase in both length and number in posterior region, to 4–5 branchial filaments.

Anterior, median and posterior parapodia with truncated chaetal lobe, aciculae emerging on dorsal half. Prechaetal lobes low transverse folds, shorter than chaetal lobe. Postchaetal lobes almost same length as chaetal lobe in anterior and median parapodia, postchaetal lobes, same length as chaetal lobe in posterior parapodia.

Notopodial cirri tapering, anterior with 4–5 articulations, median and posterior with 3. Ventral cirri longer than chaetal lobes in all chaetigers; robust and digitiform until 4–5 chaetiger, basally inflated from chaetiger 5–6, tapering to digitiform tips until 26–41 chaetiger, posteriorly inflated base decrease in size. Median and posterior parapodia with tapering ventral cirri, longer than anterior ones. ( Fig. 8G ).

Limbate chaetae marginally serrated, present in all parapodia. Pectinate chaetae flat, 11–15 teeth, with one marginal tooth longer than others, number of teeth increasing in posterior chaetae ( Fig. 8F ). Compound falciger chaetae bidentate in most chaetigers and tridentate in last chaetiger; anterior with article tapering from proximal to distal end, with narrow guard, proximal tooth directed laterally, triangular shorter than distal tooth, laterally or obliquely directed ( Fig. 8E ); median with articles longer and wider than in anterior parapodia, proximal tooth triangular, laterally directed, larger than distal tooth, laterally directed and more robust than anterior ones; posterior article shorter and narrower than anterior and median, with proximal tooth triangular, laterally directed, larger than distal tooth, laterally directed and more robust than in median parapodia ( Fig. 8H ); in last parapodia tridentate with small apical tooth directed obliquely upward, a proximal, laterally directed, triangular tooth larger than distal, laterally directed tooth ( Fig. 8H ). Aciculae yellow, usually paired; anterior ones tapered, smoothly curved blunt or sometimes mucronate tips ( Fig. 8E ); median ones curved bifid tips ( Fig. 8G ); posterior ones more curved than those in median parapodia, bifid tips ( Fig. 8H ). Subacicular hooks, yellow, tridentate, present from chaetigers 20–26. Hooks present in all middle and posterior chaetigers, usually one per parapodium, some parapodia with two, leaf-shaped guards covering first and second most basal teeth ( Fig. 8G ).

Pygidium with two pairs of anal cirri. Dorsal pygidial cirri, tapering, regularly articulated with nine articulations. Ventral pygidial cirri not articulated. Dorsal pygidial cirri approximately five times longer than ventral pygidial cirri.

Distribution. Leodice rubra ( Grube, 1856) was originally described from Saint Thomas Island (Caribbean Sea) ( Fauchald 1992). It has been reported in diverse locations in South America, along the Brazilian coast in the states of Alagoas, Bahia, Espírito Santo, Paraná, Paraíba, Rio de Janeiro, Rio Grande do Norte, Rio Grande do Sul, Sergipe and São Paulo ( Amaral et al. 2022, 2024).

Remarks. The specimens analyzed resemble redescriptions of L. rubra based on type and non-type material ( Fauchald 1992; Steiner et al. 2002) in most of their characteristics, except for maximum number of branchial filaments (9–17 in specimens examined in this study and 12–21 in redescriptions), and presence of tridentate compound falciger chaetae in last chaetigers of our specimens, which have not been described previously. However, this latter difference may be due to a larger sampling of parapodia analyzed here, since tridentate falciger compound chaetae were observed only in posterior most chaetiger, which is missing in the type material.

Figures

FIGURE 8. Leodice rubra. POLY-UFPB-2065. A—anterior end, dorsal view; B—anterior and lateral; C—anterior end, ventral view; D—maxillae, dorsal view; E—parapodium 8, compound falcigers chaetae; F—parapodium 52, pectinate chaeta; G—parapodium 52, ventral cirri, subacicular hook, compound falcigers, aciculae and notopodial cirri; H—parapodium 116, compound falcigers and aciculae.