Eunice schizobranchia Claparède 1870

Eunice schizobranchia Claparède, 1870

Eunice schizobranchia Claparède, 1870:394, pl. 2: fig. 6.—Fauvel, 1923:407408, fig. 160 a–k.

MATERIAL EXAMINED.—One specimen, MNHN, Paris, Gulf of Naples, Oct. 1899, identified by P. Fauvel.

DESCRIPTION.—Specimen complete with 731 setigers plus short, regenerating posterior end with pygidium; total length 655 mm; maximal width 5 mm at setiger 10; length through setiger 10, 10 mm. Body cylindrical through first half, thereafter tapering very nearly imperceptibly towards posterior end. All segments of about the same length, with relatively short laterally situated parapodia.

Prostomium (Figure 1001) distinctly shorter and narrower than peristomium, less than as deep as peristomium. Prostomial lobes frontally obliquely truncate, dorsally flattened, sloping from posteromedial region obliquely forwards; median sulcus distinct ventrally, very short dorsally. Eyes not observed. Antennae in a horseshoe with A-I and A-II emerging close together, well lateral to midline; A-III isolated on small medial elevation, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles slender and tapering, without articulations. A-I and A-III to middle of anterior peristomial ring; A-II to setiger 1. Peristomium flaring anteriorly; lower lip large and muscular. Separation between rings distinct dorsally and ventrally; anterior ring of total peristomial length. Peristomial cirri barely reaching posterior of anterior peristomial ring, slender and digitiform, without articulations.

Maxillary formula 1+1, 4+4, 6+0, 2+6, and 1+1. Mx III part of arc with left Mx IV. Mx V reduced with barely distinct teeth. Mx VI absent.

Branchiae (Figure 100q) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 67 to setiger 730. Branchiae present to near posterior end, present on more than 65% of total number of setigers. First 100 branchiae single filaments; maximum seven filaments. Number of filaments retained through rest of body; even in last branchiated setigers 6 filaments may be present. Branchial stems short, strongly tapering. Filaments long and digitiform, outreaching notopodial cirri in all but few first setigers.

Anterior neuropodial acicular lobes (Figure 100i) rounded with aciculae emerging above midline, above emergence of aciculae distinct, tapering cirri present. Median and posterior neuropodial acicular lobes triangular, retaining small superior tab even in last setigers. All presetal lobes low, transverse folds. Anterior postsetal lobes higher than acicular lobes and rounded, following outline of acicular lobes closely from about setiger 30. First 9 ventral cirri tapering to digitiform tips. Ventral cirri basally inflated from setiger 10 through rest of body. Inflated bases nearly spherical; narrow tips tapering. Bases of posterior ventral cirri thick, transverse welts; narrow tips short and button-shaped. All notopodial cirri basally slightly inflated, retaining same length throughout, decreasing in thickness posteriorly, without articulations.

Limbate setae marginally serrated. Pectinate setae (Figure 100m), apparently missing in first 20 setigers, slender, tapering, furled with thickened margins. One marginal tooth very long; ~7 rather coarse teeth present. Compound falcigers in thick, double fascicles in anterior setigers, decreasing in numbers posteriorly, reduced to single anterior fascicle by setiger 25. Shafts of compound falcigers (Figure 100j,k,p) slightly inflated, marginally serrated; internal striations and beaks distinct. Appendages of hooks in anterior fascicles of anterior setigers (Figure 100k) long and slender, tapering, bidentate. Both teeth distinct and slender. Proximal teeth slightly smaller than distal teeth, directed laterally. Distal teeth slender and nearly erect. In posterior fascicles of anterior setigers, especially towards upper ends of fascicles appendages relatively longer and teeth reduced (Figure 100j). Proximal teeth small knobs and distal teeth short, erect knobs. In posterior setigers appendages long, slender and tapering (Figure 100p); head large. Proximal teeth large, laterally directed, triangular. Distal teeth curved, very much smaller than proximal teeth. Guards longer than appendages in all hooks, symmetrically rounded and marginally strongly serrated; mucros absent. Pseudocompound falcigers and compound spinigers absent. All aciculae (Figure 100o) tapering, distally straight; cross-sections round. In anterior setigers up to 4 aciculae in oblique series, in posterior setigers all aciculae single. Anterior aciculae black, becoming lighter posteriorly, light brown near posterior end. Subacicular hooks (Figure 100n) clear and translucent, rather than yellow, bidentate. Hooks first present from setiger 60, first irregularly occurring, by setiger 300 present in all setigers, always single (except for replacements). All hooks emerging nearly at right angles with aciculae, projecting well beyond ventral cirrus in all setigers. Hooks distally tapering. Proximal teeth larger than distal teeth; both teeth directed distally.

UNKNOWN MORPHOLOGICAL FEATURES.—Pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—None.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 22, 56, 60. Unknown Characters: 13, 14, 42, 74, 78.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—None.

Eunice schizobranchia é uma espécie de anelídeo pertencente à família Eunicidae.

A autoridade científica da espécie é Claparède, tendo sido descrita no ano de 1870.

Trata-se de uma espécie presente no território português, incluindo a sua zona económica exclusiva.

Known from seamounts and knolls