Eunice excariboea Fauchald 1992

Eunice excariboea

Eunice cariboea Grube, 1856:57 [in part].

MATERIAL EXAMINED.—Holotype and 1 paratype, ZMC (uncataloged), St. Croix, West Indies, coll. H. Kröyer (part of original material of E. cariboea Grube).

COMMENTS ON MATERIAL EXAMINED.—The holotype is the larger of the two specimens examined.

DESCRIPTION.—Holotype incomplete, of unknown sex, with 136 setigers; length 34 mm; maximal width 2 mm at setiger 10; length through setiger 10, 3.7 mm. Anterior part of body including prostomium and peristomium cylindrical. Body widening rapidly through first few setigers, becoming nearly twice as wide as prostomium by setiger 10, slightly dorsoventrally flattened with parapodia elevated on low lateral ridges.

Prostomium (Figure 43o) ∼ as deep, very nearly as wide as peristomium. Prostomial lobes frontally rounded, dorsally flattened; median sulcus shallow. Eyes behind bases of A-I, dark. Antennae in a horseshoe; A-I and A-II emerging close together, near outer edges of prostomium, separated by gap from A-III, similar in thickness. Ceratophores ring-shaped in all antennae, without articulations. Ceratostyles slender and digitiform, with up to 14 closely spaced, indistinct articulations in A-III, articulated to bases of ceratostyles. A-I to posterior peristomial ring; A-II and A-III to setiger 2. Peristomium slightly flaring anteriorly. Separation between rings distinct dorsally and ventrally; anterior ring of total peristomial length. Peristomial cirri to middle of anterior peristomial ring, slender and digitiform, without articulations.

Jaws not examined.

Branchiae (Figure 43n) present, palmate, about as long as notopodial cirri, not reduced in mid-body region. Branchiae from setiger 78–79 to end of fragments. Most branchiae with 2 long, narrow filaments emerging from joint bases at dorsal edge of notopodial cirri; up to 3 filaments present. Stems reduced. Filaments longer than notopodial cirri.

Neuropodial acicular lobes (Figure 43i) rounded; anterior setigers with small rounded tabs dorsal to emergence of aciculae; tabs absent in posterior setigers; aciculae emerging at midline. Lateral body wall forming low ridges with acicular lobes at distal ends from about setiger 25. Pre- and postsetal lobes low folds; anterior presetal lobes distinctly lower than acicular lobes; in posterior setigers all 3 lobes paralleling each other closely. First 4 ventral cirri thick and tapering. Ventral cirri basally inflated from about setiger 5. Inflated bases distinct, inflated ridges along ventral side of neuropodia in all later setigers; narrow tips tapering or digitiform. Anterior notopodial cirri tapering with 4 articulations; number of articulations reduced to one in posterior setigers; notopodial cirri becoming digitiform in far posterior setigers.

Limbate setae slender, very finely serrated. Pectinate setae (Figure 43m) very small, with slender shafts. Blades furled, flaring. Both marginal teeth longer than other teeth, with ∼12 teeth. Shafts of compound falcigers distinctly inflated and marginally serrated; beaks distinct. Anterior appendages (Figure 43j) tapering, bidentate. Proximal teeth larger than distal teeth; both teeth tapering, distally curved towards each other, forming a crabclaw-like distal end. Posterior appendages (Figure 43l) shorter and more abruptly tapering than anterior ones, bidentate. Proximal teeth much larger than distal teeth, triangular, directed laterally. Distal teeth slender, tapering and nearly erect. Guards symmetrically rounded and marginally serrated in all setigers; mucros absent. Pseudocompound falcigers and compound spinigers absent. Aciculae paired anteriorly, single posteriorly, amber-colored, tapering to straight tips; cross-section round. Subacicular hooks (Figure 43k) pale amber, bidentate. Hooks first present from setiger 87 (78 in paratype), missing in many setigers, always single (except for replacements). Hooks gently sigmoid, tapering, with distinct head. Proximal teeth larger than distal teeth, directed laterally. Distal teeth very small, directed obliquely distally. Guards distally rounded.

UNKNOWN MORPHOLOGICAL FEATURES.—Jaw structure; pygidium and anal cirri.

EXPECTED STATES OF SELECTED UNKNOWN FEATURES.—Mx III short, forming part of distal are with left Mx IV.

CHARACTERS USED IN PREPARATION OF KEY NOT SCORED.—Inappropriate Characters: 34, 56, 60. Unknown Characters: 1, 2, 36–40, 42, 74, 78.

ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—37,1; 38,1.