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Eunice djiboutiensis Gravier 1900

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Eunice djiboutiensis Gravier, 1900

Eunice aphroditois djiboutiensis Gravier, 1900:224–229, figs. 73–77, pl. 13: figs. 63, 67.

MATERIAL EXAMINED.—One syntype, MNHN, Paris, Djibouti, coll. Jousseaume and Goudieu, 1897.

COMMENTS ON MATERIAL EXAMINED.—The anterior end has been flattened and details of the prostomium and peristomium are difficult to distinguish. Gravier originally had two specimens.

DESCRIPTION.—Syntype with 318 setigers, missing a few setigers posteriorly; length 320 mm; maximal width 10 mm at setiger 10; length through setiger 10, 20 mm. Body cylindrical, very stiff, dark reddish brown.

Prostomium distinctly shorter than peristomium. Prostomial lobes apparently frontally rounded, dorsally slightly inflated; median sulcus deep. Eyes at bases of A-I. Antennae in a straight line, evenly spaced, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles incomplete, apparently digitiform, rather thick, without articulations. No antennae projecting beyond peristomium. Peristomium massive, cylindrical; lower lip and nuchal folds scalloped. Separation between rings distinct dorsally and ventrally; anterior ring 8/9 of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, without articulations, basally inflated, tapering to thick, digitiform tips, without articulations.

Maxillary formula according to Gravier (1900:227–228) 1+1, 5+6, 6+0, 4+8, and 1+1.

Branchiae (Figure 38i) present, pectinate, distinctly longer than notopodial cirri, not reduced in mid-body region, erect. Branchiae from setiger 5 to end of specimen. All branchiae with two or more filaments; maximum 25 filaments; number of filaments reduced slowly posteriorly to about 5. Branchiae longer than notopodial cirri in anterior of body; posterior notopodial cirri clearly longer than branchiae. Total length of branchiae is less than body width in all setigers. Anterior stems short, thick, tapering stiff; posterior stems slender, digitiform. Filaments thick, digitiform, shorter than notopodial cirri.

Anterior neuropodial acicular lobes wide and truncate; posterior acicular lobes also truncate, but narrower with aciculae emerging above midline. Pre- and postsetal lobes low folds. First 5 ventral cirri thick, tapering, thereafter modestly basally inflated through next 20–30 setigers. Inflated bases ovate, narrow tips digitiform. Inflated bases gradually reduced; ventral cirri broadly transversely attached tapering to digitiform tips in last 150 setigers. Notopodial cirri basally inflated, tapering to thick, digitiform tips, without articulations.

Limbate setae frayed marginally. Pectinate setae (Figure 38h) numbering up to 25 in a parapodium. Shafts wide, cylindrical. Blades flat, flaring. One marginal tooth longer than other teeth; with 15–25 teeth. Shafts of compound falcigers at least as thick as aciculae, tapering, marginally smooth, copper-colored. All appendages lost, illustrated by Gravier (1900, fig. 76) as short, triangular, bidentate. Proximal teeth short, directed obliquely distally; distal teeth nearly erect; small bosses apparently present between proximal and distal teeth. Guards asymmetrically bluntly pointed; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae single in most parapodia, with dark brown to black cores and clear sheaths, distally tapering to slender, gently curved tips; cross-section round. Subacicular hooks (Figure 38g) with dark brown to black cores and clear sheaths, bidentate. Hooks first present from setiger 81, present in less than half the next 100 setigers, becoming more frequent in posterior half of body and present in all setigers near posterior end of specimen, always single (except for replacements). Hooks slender, tapering smoothly, with very small heads. Proximal teeth triangular and directed laterally; distal teeth nearly erect and sharply tapered; at junction between teeth small, sharply pointed bosses on both sides of hooks, making hooks appear quadridentate in frontal view.

UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between Mx III and left Mx IV; all features associated with far posterior setigers, including branchial distribution; pygidium and anal cirri.

EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEATURES.—Mx III forms a distal are with left Mx IV; branchiae continued to near the posterior end.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 22, 56, 58, 59. Unknown Characters: 1, 2, 11, 12, 36–38, 40, 42.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—11,2; 12,2; 37,1; 38,1.
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cc-by-nc-sa-3.0
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

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Eunice aphroditois djiboutiensis Gravier, 1900

Eunice aphroditois djiboutiensis Gravier, 1900:224–229, figs. 73–77; pl. 13: figs. 63–67.
license
cc-by-nc-sa-3.0
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