Eunice sensu latu (Annelida: Eunicidae) from Australia: description of seven new species and comments on previously reported species of the genera Eunice, Leodice and Nicidion
Author
Zanol, Joana
Author
Hutchings, Pat A.
Author
Fauchald, Kristian
text
Zootaxa
2020
2020-03-05
4748
1
1
43
journal article
10.11646/zootaxa.4748.1.1
4210c98c-65e5-4557-a166-49fd6f9ead0a
1175-5326
3697522
B9EC373A-DF9B-47E2-916C-CF211D8F0727
Eunice cultrifera
,
new species
(
Figs 5
,
6
,
7
)
Material examined. New South
Wales
.
Jervis Bay
,
35°03.93’S
,
150° 45.60’E
,
20 m
, sandy bottom
AM
W.20544 (
HOLOTYPE
) parapodia 10, 50, 250, 360 removed and mounted for SEM (
AM
W.20544.001)
.
PARATYPES
,
Jervis Bay
, ACT,
35°03.93‘ S
,
150° 45.60‘E
,
20 m
depth
, flat sandy bottom
CSIRO
Fisheries
,
26 Feb 1991
,
AM
W.20537 (l),
AM
W.20538 (l),
AM
W.20539 (l),
AM
W.20540 (1),
AM
W.20541 (l),
AM
W.20542 (l),
AM
W.20543 (l),
AM
W.20546 (l),
AM
W.20547 (1),
AM
W.20548 (l),
AM
W.20549 (l),
AM
W. 20550 (1),
AM
W.20551 (l),
AM
W.20552 (l),
AM
W.20553 (1),
AM
W.20554 (l),
AM
W.20555 (l),
AM
W.20556 (1),
AM
W.20558 (1) plus tube.
Queensland
.
Port Curtis
,
23°55’S
,
151°23’E
,
20 m
,
AM
W.197115 (l).
Description
.
Holotype
incomplete with 360 chaetigers; total length
300 mm
; length through chaetiger 10
15 mm
; maximum width
7 mm
at chaetiger 10. Body dorsally inflated; parapodia, especially anteriorly, short. As preserved, bone-colored with no distinct color patterns.
Prostomium dorsally inflated and anteriorly rounded; depressed around palpal bases; bearing deep median sulcus (
Figs 5A, B
;
6A
). Antennae in straight line; palps directly anterior to lateral antennae. Ceratophores and palpophores short, ring-shaped. Ceratostyles and palpostyles tapering; irregularly articulated. Median antenna longest, but no antennae extending beyond peristomium. Eyes located between bases of lateral antennae and palps. Peristomium slightly flaring anteriorly; anterior ring 3/4 of total peristomial length; separation distinct ventrally and dorsally; less visible laterally, but visible around body. Peristomial cirri tapering; not extending beyond anterior peristomial ring; irregularly articulated.
Maxillary formula 1+1, 6+4, 7+0, 4+8, 1+1, 1+1 (
Fig. 5C
). MxVI ridge-shaped. MxIII short; forming part of distal arc with left MxIV and V. Left MxIV running dorsal to ventral, teeth restricted to the dorsal quarter, and with basal plate along ventral half of the plate. Maxillary formula of
paratype
(AM W.20538) 1+1, 4+4, 7+0, 2+8, 1+1, 1+1 (
Fig. 6B
). Mandibles missing calcareous cutting plate.
Branchiae present from chaetiger 50 to end of body (observed in complete
paratypes
, AM W.20554 complete but in 2 pieces; AM W.20556 complete but in 4 pieces). Most branchiae single, slightly flattened filaments; far posterior chaetigers with double similar filaments (
Figs 5J, N
;
6F
).
FIGURE 5.
Eunice cultrifera
n. sp.
AM W.20544. A, anterior end, lateral view; B, anterior end, dorsal view; C, maxillae, dorsal view, compressed; D, parapodium 4, anterior view; E, compound spiniger chaeta, parapodium 4; F, pectinate chaeta, parapodium 4; G, pectinate chaeta, parapodium 25; H, compound spiniger chaeta, parapodium 25; I, parapodium 25, anterior view; J, parapodium 140, anterior view; K, subacicular hook, parapodium 140; L, acicula, parapodium 140; M, pectinate chaeta, parapodium 140; N, parapodium 330, anterior view; O, pectinate chaeta, parapodium 330.
FIGURE 6.
Eunice cultrifera
n. sp.
A, C–K, AM W.20544. B, AM W.20538. A, anterior end, dorsal view; B, maxillary apparatus, dorsal view, left MxVI broke off during dissection; C, pectinate chaeta, parapodium 10; D, parapodium 10, anterior view; E, pectinate chaeta, parapodium 360; F, parapodium 360, anterior view; G, parapodium 250, anterior view; H, subacicular hook, parapodium 360; I, compound spiniger chaeta, parapodium 10; J, compound falciger chaeta, parapodium 360; K, subacicular hook, parapodium 250.
Anterior chaetal lobes obliquely truncate with acicula emerging near dorsal edge (
Figs 5D, I
;
6D
). Median chaetal lobes slightly obliquely truncate; higher at dorsal edge with acicula emerging above midline (
Fig. 5J
). Posterior chaetal lobes becoming increasingly triangular (
Figs 5N
;
6F, G
). All prechaetal lobes low transverse folds. Anterior postchaetal lobes slightly longer than chaetal lobes, truncate; highest near dorsal edge of neuropodium (
Fig. 5D
). Median and posterior postchaetal lobes low folds. Ventral cirri thick, triangular, distally blunt in anterior chaetigers; inflated bases start at chaetiger 5 becoming thick ventral ridges with short narrow tips at about chaetiger 10 (
Fig. 5D
); posterior thumb-like from around chaetiger 150. Anterior notopodial cirri distinctly inflated near the base of styles; styles irregularly articulated and separated from cirrophores by distinct grooves. Posterior notopodial cirri short digitate with inflated bases, equal to length of parapodia with chaetae, lacking a cirrophore (
Figs 5N
;
6F
).
Limbate chaetae present in all chaetigers. Pectinate chaetae small, scoop-shaped with transverse distal edges, with slender shafts; distinctly flaring distally; one marginal tooth distinctly longer than other teeth (
Figs 5F, M, O
;
6C, E
). Anterior pectinate chaetae with up to 6–9 teeth. Median and posterior pectinate chaetae with up to 10–13 teeth. Shafts of compound chaetae distally slightly inflated (
Fig. 5E, H
). Anterior and median chaetigers with compound spiniger chaetae; appendages triangular, knife-blade shaped distally slightly irregular (
Figs 5E, H
;
6I
). Posterior chaetigers with compound falciger chaetae, appendages bidentate with distal tooth erect, proximal tooth triangular, directed laterally with tip curved distally; guards rounded (
Fig. 6J
). Internal notoaciculae present in all chaetigers; neuropodial acicula anteriorly and posteriorly single, medially double. All neuropodial acicula tapering to blunt tips; tip distally bent in posterior chaetigers (
Figs 5L
;
6F, G
). Aciculae and subacicular hooks have distinct dark cores and clear sheaths. Subacicular hooks with dark brown to black cores; with sharply tapered erect distal tooth and narrow, tapering proximal tooth, distinctly narrower at base than width of hook at that point (
Figs 5K
;
6H, K
). Subacicular hooks first present from chaetiger
90 in
holotype
; present in all chaetigers thereafter; always single.
Variation.
Variation in number of chaetigers and length of complete individuals (
Holotype
,
paratypes
AM W.20554 and AM W.20556) is 360 chaetigers and
300 mm
, 520 chaetigers and ˜
290 mm
, and 297 chaetigers and
130 mm
respectively. Start of branchiae varies between chaetigers 40 to 55. Subacicular hooks are first present from chaetiger 50 to 97, being more posterior in larger specimens. On these specimens the ventral cirri become ventral thickened ridges at chaetiger 10 and around 120 and 145 chaetigers becoming digital in shape.
Type
locality
.
Jervis Bay
,
New South
Wales
,
35°03.93’S
,
150° 45.60’E
.
Habitat notes
.
Eunice cultrifera
n. sp.
, lives in large complex tubes tubes or tube-systems forming masses on sandy bottom present in roughly
10–20 m
depth (
Fig. 7
). Most of the materal comes from Jervis Bay.
FIGURE 7.
Eunice cultrifera
n. sp.
A, tube
in situ
covered by epibionts photo by Nathan Knott; B, AM W.20558 tube, extracted from sediment
Etymology
. The species name, Latin for knife-bearer, refers to the shape of the appendage of the anterior compound chaetae.
Remarks
. Compound chaetae with spinigerous appendages are present in
E. cultrifera
n. sp.
,
E. impexa
Grube, 1878
,
E. taoi
Hsueh & Li, 2014
,
E. tubicola
(
Treadwell, 1922
)
,
E. tubifex
Crossland, 1904
. In
E. impexa
and
E. taoi
the branchiae may have six to seven branchial filaments, respectively, in a palmate, often irregular arrangement, and pectinate arrangement, also both species have subacicular hooks lighter than aciculae and two hooks present in several chaetigers;
E. tubicola
has single branchial filaments terminating well before the posterior end, compound spiniger chaetae restricted to anterior most chaetigers, aciculae single and yellow; and
E. tubifex
has up to four branchial filaments present through a long body region and aciculae distally geniculated. All these differences clearly distinguish these previously described species from
E. cultrifera
n. sp.
Both
E. impexa
and
E. tubifex
have been reported from
Australia
, but records of the latter are probably dubious as discussed below.
Eunice cultrifera
n. sp.
probably belongs to the clade containing
E. impexa
and
Eunice filamentosa
Grube,
1856
in
Zanol
et al.
(2014)
. It shares with them the shape of prostomium, late start and shape of branchiae, inflated base of ventral cirri as thick ventral ridges, and left MxIV with teeth restricted to the dorsal portion of the plate.