A Review of the Genus Eunice - Smithsonian Institution Libraries

NUMBER 523 283
TABLE 14.—Variable and invariable features in the type lot of Eunice pycnobranchiata (N = number of
individuals examined; SD = standard deviation; measurements in mm; * = SD not calculated).
VARIABLE FEATURES
No. of setigers
Total length
Maximal width
Length through 10
No. of antennal articulations
No. of peristomial cirral articulations
Branchiae first present from setiger no.
Max. no. of branchial filaments
Ventral cirri inflated through setiger no.
Subacicular hooks first present from setiger no.
N
2
2
4
4
4
4
4
4
4
4
Max.
140
105
7
13
17
5
8
5
50
31
Min.
129
70
2
5
8
3
5
1
32
23
Mean
134.5
87.5
5
9.5
11.75
4
6
3.5
40.75
27.5
SD
*
*
2.16
3.32
3.86
1.15
1.41
1.91
7.37
3.42
INVARIABLE FEATURES
Separation between rings distinct
Acicular color
Aciculae distally
Subacicular color
No. of subacicular teeth
N=4
dorsally and ventrally
brown
tapering; bent
brown
2
gap, with A-I slimmer than other 3. Ceratophores ring-shaped
in all antennae, without articulations. Ceratostyles tapering,
with up to IS irregular, cylindrical articulations. Antennae
reaching posterior peristomial ring; A-I I and A-I 11 similar in
length; A-I somewhat shorter. Peristomium cylindrical with
distinct muscular lower lip. Separation between rings distinct
dorsally and ventrally; anterior ring about
5 /« of total
peristomial length. Peristomial cirri to middle of anterior
peristomial ring, with 3 articulations.
Maxillary formula according to Mclntosh (1885, fig. 54)
1+1, 5+5,6+0, 6+8, 1+1. Mx III part of distal arc with left Mx
IV and V.
Branchiae present, pectinate, about as long as notopodial
cirri, not reduced in mid-body region. Branchiae from setiger
5-6 to end of fragments. Where best developed branchiae with
4 short thick filaments.
All neuropodial acicular lobes (Figure 95c) rounded;
aciculae emerging dorsal to midline. Presetal lobes low,
transverse folds. Anterior postsetal lobes forming collars
around dorsal edge of acicular lobes. Median postsetal lobes
low, transverse folds. Anterior ventral cirri digitiform. Median
ventral cirri with barely visible inflated bases. Inflated bases
ovate; narrow tips digitiform. Anterior notopodial cirri digitiform,
with 2 to 4 irregular articulations. Median notopodial
cirri basally somewhat inflated, without articulations.
Limbate setae slender. Pectinate setae (Figure 950 flat,
flaring. Both marginal teeth slightly longer than other teeth;
-15 teeth present. Shafts of compound falcigers (Figure 95e)
tapering, marginally smooth with internal striations. Appendages
short, bidentate. Proximal teeth shorter than distal teeth,
triangular, directed laterally. Distal teeth tapering, nearly erect.
Guards distally asymmetrically bluntly pointed; mucros absent.
Pseudocompound falcigers and compound spinigers absent.
Aciculae single in first few setigers, thereafter paired, black,
tapering, straight; cross-section round. Subacicular hooks
(Figure 95d) black, bidentate. Hooks first present from setiger
28 or 29, present in all setigers thereafter, always single (except
for replacements). Proximal teeth much larger than distal teeth;
both teeth directed obliquely distally.
UNKNOWN MORPHOLOGICAL FEATURES.—Relationship between
Mx III and left Mx IV; all features associated with
posterior setigers; pygidium and anal cirri.
EXPECTED STATES OF UNKNOWN MORPHOLOGICAL FEA-
TURES.—Mx III short, forming part of distal arc with left Mx
IV.
CHARACTERS USED IN PREPARATION OF KEY NOT
SCORED.—Inappropriate Characters: 56, 58, 59. Unknown
Characters: 1, 2,4, 6, 13, 14, 34, 36-40,42, 47, 50, 51, 60,
63,74.
ASSUMED STATES FOR PURPOSE OF PREPARING KEY.—37,1;
38,1.
REMARKS.—The specimen from Bass Strait differs slightly
from the specimen from Twofold Bay in length of antennae and
in development of branchiae. Branchiae more prominent in
Bass Strait specimens than in the other specimen. These
differences are not considered to be of value as specific
characters. Mclntosh commented on the variability in the
number of teeth in the jaws. Such variability was not observed
in the current study.
Eunice pycnobranchiata is compared to similar species in
Tables 27 and 32. It is the only species in Table 32 in which the
branchiae and the notopodial cirri are similar in length; in two
species, the branchiae are distinctly shorter and in the others,
they are distinctly longer than the notopodial cirri. The length
differences are very obvious in all cases.
The species has been considered a junior synonym of E. afra
and E. laticeps. It differs clearly from E. afra by having
branchiae from setigers 5-6 rather than from setiger 16. Eunice