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Eunice kerguelensis Averincev 1972

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Eunice kerguelensis Averincev, 1974

Eunice kerguelensis Averincev, 1974:172, pl. 31: figs. 11–14.

MATERIAL EXAMINED.—Holotype, ZIL, 1/15808, Antarctic Ocean near Kerguelen Island, 49°38′7″S, 70°43′7″, OB sta 121, 141 m, 20 May 1956, coll. Averincev, Ushakov, Belayev.

COMMENTS ON MATERIAL EXAMINED.—The anterior end has been deeply dissected and especially the peristomium has been partially reconstructed in the illustration.

DESCRIPTION.—Holotype incomplete, of unknown sex, with 26 setigers; length 4 mm; maximal width 0.3 mm; length through setiger 10, 1.2 mm. Body cylindrical throughout.

Prostomium (Figure 60c) about as long as peristomium, about as wide as peristomium, as deep as of peristomium. Prostomial lobes frontally rounded, dorsally very slightly inflated; median sulcus shallow. Eyes between bases of A-I and A-II, large reddish. Antennae in horseshoe, evenly spaced, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles digitiform, with up to 9 angular articulations in A-III. A-I to posterior peristomial ring; A-II (only 1 present) to setiger 4; A-III to setiger 4. Peristomium cylindrical, with distinct muscular lower lip. Separation between rings distinct on all sides; anterior ring ~ of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, digitiform, without articulations.

Maxillary formula 1+1, 8+11, 8+0, 7+10, and 1+1 according to Averincev (1974:172).

Branchiae present, palmate, longer than notopodial cirri, not reduced in mid-body region. Branchiae from setiger 3 (according to Averincev, both parapodia on setiger 3 now missing) to end of fragment. Where best developed, branchiae with 2 slender tapering filaments. Filaments of same length as notopodial cirri.

Neuropodial acicular lobes distally rounded; aciculae emerging at midline. Pre- and postsetal lobes low, transverse folds. First 3 ventral cirri thick, tapering. Ventral cirri becoming basally inflated from setiger 4–5. Inflated bases ovate; narrow tips tapering. Inflated bases retained to end of fragment. Notopodial cirri basally slightly inflated, tapering to narrow tips, without articulations.

Limbate setae marginally smooth. Pectinate setae now missing, illustrated by Averincev (1974, pl. 31: fig. 13) as tapering, with 1 marginal tooth very much longer than other teeth, with ~10 teeth totally. Shafts of compound falcigers (Figure 60a) inflated, marginally serrated. Appendages slender, tapering; heads large, bidentate. Proximal teeth smaller than distal teeth, tapering, directed basally. Distal teeth curved, directed nearly laterally. Guards symmetrically sharply pointed, sometimes appearing mucronate. Pseudocompound falcigers and compound spinigers absent. Aciculae mostly paired, yellow, tapering, straight; cross-sections round. Separation between core and sheath indistinct in both aciculae and subacicular hooks. Subacicular hooks (Figure 60b) yellow, tridentate with teeth in a crest. Hooks first present from setiger 19, present in all setigers thereafter always single (except for replacements). Hooks with large curved main fangs. Fangs decreasing evenly in size distally.

UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between Mx III and left Mx IV; all features associated with posterior parapodia; pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—The high number of teeth in Mx III suggests that this jaw piece was long and located behind left Mx II rather than part of a distal arc.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 34, 56. Unknown Characters: 1, 2, 4, 6, 36–40, 42, 47, 50, 57–60, 63, 65, 67.

bibliographic citation
Fauchald, Kristian. 1992. "A Review of the Genus Eunice (Polychaeta: Eunicidae) Based upon Type Material." Smithsonian Contributions to Zoology. 1-422. https://doi.org/10.5479/si.00810282.523