A Review of the Genus Eunice - Smithsonian Institution Libraries

NUMBER 523 285
167. Eunice reducta Fauchald, 1970
FIOURE 96a-h; TABLES 27, 30
Eunice reducta Fauchald. 1970:39-43, pi. 5: figj. a-i.
MATERIAL EXAMINED.—Holotype, AHF Poly 0338, Gulf of
California, Mexico, entrance of Bahia Agua Verde, from
25°31'36"N, lll°03'15"W to 25°31'40"N, lll o 04'13"W, 42-
48 m, dredge, sand, mollusks, crabs, 17 Mar 1949, Velero IV,
sta 1743-49.
DESCRIPTION.—Holotype complete with 298 setigers; total
length 318 mm; maximal width 6 mm; length through setiger
10, 15 mm. Body anteriorly truncate, cylindrical, tapering
slowly posteriorly to slender posterior end with crowded short
segments; most body segments only slightly wider than long;
parapodia strictly lateral. Paired anal cirri barely longer than
pygidium, without articulations; dorsal edge of pygidium
smooth.
Prostomium (Figure 96a) distinctly shorter and narrower
than peristomium, as deep as
x li of the peristomium.
Peristomial lobes frontally obliquely truncate, dorsally excavate
with a thickened rim; median sulcus shallow, but wide.
Eyes posterior to bases of A-I, black. Antennae in a horseshoe,
evenly spaced, similar in thickness. Ceratophores ring-shaped
in all antennae, without articulations. Ceratostyles digitiform,
with up to 3 cylindrical, indistinct articulations. A-I to middle
of anterior peristomial ring; A-I I and A-I II to posterior
peristomial ring; A-I 11 slightly longer than A-I I. Peristomium
cylindrical; lower lip distinct muscular. Separation between
rings distinct dorsally and ventrally; anterior peristomial ring
4 /5 of total peristomial length. Peristomial cirri to middle of
anterior peristomial ring, tapering, without articulations.
Maxillary formula 1+1, 444, 8+0, 4+10, and 1+1 according
to Fauchald (1970:42).
Branchiae (Figure 96g) present, pectinate, distinctly longer
than notopodial cirri, not reduced in mid-body region, erect.
Branchiae from setiger 4 to setiger 131. Branchiae terminating
well before posterior end, present on less than 55% of the total
number of setigers. Last 6 pairs single filaments, all others with
at least 2 filaments; maximum number of filaments 21 in a trim
series. Branchial stems long, erect, tapering. Filaments short,
digitiform. Some filaments furcate. Filaments and notopodial
cirri similar in length.
Anterior neuropodial acicular lobes distally truncate with
aciculae emerging at midline. Posterior neuropodial acicular
lobes conical with aciculae emerging at tip. All pre- and
postsetal lobes low folds. First 4 ventral cirri thick, tapering.
Ventral cirri basally inflated from about setiger 5 through about
setiger 50. Inflated ventral cirri large, irregularly rounded;
narrow tips absent. Ventral cirri increasingly digitiform in far
posterior setigers, but always shorter than notopodial cirri.
Anterior notopodial cirri thick, medially inflated, decreasing
rapidly in width posteriorly. Postbranchial notopodial cirri half
as long as anterior notopodial cirri, slender, digitiform.
Pre-branchial and branchial notopodial cirri with 2 or 3
articulations; postbranchial notopodial cirri without articulations.
Limbate setae tapering, marginally pilose. Pectinate setae
(Figure 96d,f) with flattened shafts; blades flat, flaring. One
marginal tooth very much longer than other teeth; -20 teeth in
median and posterior setae; -10 in anterior setae. Shafts of
compound falcigers (Figure 96b,e,h) thick, tapering, marginally
smooth. Appendages short, triangular, bidentate. Proximal
teeth very much smaller than distal teeth; anterior proximal
teeth small, distally directed spur, posterior proximal teeth low,
triangular elevations. Distal teeth very large, blunt, erect.
Guards asymmetrically bluntly pointed; mucros absent. Pseudocompound
falcigers and compound spinigers absent. Aciculae
paired in anterior setigers, single in posterior setigers, dark
brown to black, tapering, blunt-tipped; cross-section round.
Subacicular hooks (Figure 96c) dark brown to black, bidentate.
Hooks first present from setiger 45, present in all setigers
thereafter, always single (except for replacements). Hooks
tapering gently to small head. Proximal teeth about half as large
as distal teeth; both teeth directed distally.
UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between
Mx III and left Mx IV.
EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEA-
TURES.—Mx III forming part of a distal arc with left Mx IV.
CHARACTERS USED IN PREPARATION OF KEY NOT
SCORED.—Inappropriate Characters: 56, 58, 59. Unknown
Characters: 4,6,42, 74,78.
ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—
None.
REMARKS.—Fauchald (1970) indicated that subacicular
hooks could be present from setigers 34-49 in non-type
specimens of this species from western Mexico. Eunice reducta
belongs to group B-2, but differs from most species in the
group by having a long abranchiate posterior end. It is
compared to similar species in Tables 27 and 30. The two other
species in Table 30 with abranchiate posterior end, E. coccinea
and E. fimbriata, have 10 and five branchial filaments
respectively; E. reducta has 21 filaments where the branchiae
are best developed.
Eunice rissoi Quatrefages, 1866
Eunice rissoi Quatrefages, 1866:315-316, pi. 10: fig.5.
Eunice vittata.—Gmbc, 1870a:295 [in part, not Nereis vittata Chiaje, 1829].
REMARKS.—No type specimens are available.
In the original description A-I 11 is mentioned as being very
much longer than the other antennae; peristomial cirri were
described as long; branchia present from setiger 3 (ring 4) with
up to 5 filaments.
Grube in his review of material in the Paris Museum
indicated that branchiae began on setiger 4 and were absent
from the last 10 of a total of 105 segments present in a complete
specimen. A-I 11 reached setiger 4 and had a few long