A revision of Australian Pectinariidae (Polychaeta), with new species and new records
Author
Zhang, Jinghuai
Author
Hutchings, Pat
text
Zootaxa
2019
2019-05-27
4611
1
1
70
journal article
26668
10.11646/zootaxa.4611.1.1
6f5e6228-cb60-4d34-94d4-637d8bfd59d7
1175-5326
3229987
178FED38-5FEA-417F-B5DC-807D943B641C
Lagis
sp.
Figs 20–21
, Table 2
Material examined.
Australia
,
Queensland
:
AM
W.30903,
1 spec.
, Weipa, Lorim Point Wharf,
12°40’S
141°57’E
, coll. CRC Reef Research Centre Ltd,
01 Oct 1999
, benthic grab
.
Description
. Preserved specimen pale in colour, conical in shape (
Fig. 20A
). Specimen broken, body length 10.5 mm including paleae and scaphe, width 1.2 mm at cephalic regions (
Fig. 20A
).
Cephalic veil circular-arched, connected to opercular lateral margin at base of 1
st
pair of tentacular cirri, with 12 smooth cirri on anterior margin (
Fig. 20B
–
C
). Pair of lateral ear-shaped lobes present behind cephalic veil, between buccal cavity and segment 1. Buccal tentacles broken, arising from posterior to cephalic veil (
Fig. 20B
–
C
).
Operculum semicircular; dorsal and lateral margin well developed, smooth; ventral margin (opercular ridge) with 14 pairs of stout and golden paleae, curved dorsally, with finely pointed tips (
Fig. 20A
–
C
).
First pair of tentacular cirri with annuli, not extending beyond tips of paleae, arising from connection of opercular margin and paleal ridge (
Fig. 20B
–
C
). Pair of small ventral lappets present posterior to tentacular cirri of segment 1. Ventral region of segment 1 covered by buccal tentacles and ventral lobes of segment 2 (
Fig. 20B
–
C
).
Second pair of tentacular cirri extending beyond opercular margin, with annuli, on latero-median connecting ridge on segment 2, inserted more dorsally than 1
st
pair of tentacular cirri (
Fig. 20C
). Ventral lobes contorted on segments 2
–
6 probably as a result of fixation. Segment 2 without dorsal lobe.
Comb-like branchiae on segments 3
–
4, consisting of series of loose, flat lamellae (
Fig. 20A, C
). Branchiae on segment 3 larger and inserted more ventrally than those on segment 4 (
Fig. 20A
).
The shape of ventral lobes on segments 3–6 is difficult to interpret due to state of preservation of this single specimen and additional material is needed to describe these structures.
FIGURE 20.
Lagis
sp. Methyl Green stained body (AM W.30903): A. Dorsal view of anterior and posterior regions; B. Close up of anterior end, in ventral view; C. Ventral view of anterior end; D. Lateral view of posterior end; E. Dorsal view of posterior end. Abbreviations: af, anal flap; br, branchiae; bt, buccal tentacles; cv, cephalic veil; op, operculum; p, paleae; s, segment; sc, scaphe; sh, scaphal hooks; tc, tentacular cirri.
Notopodia other than those of segment 1 which bear paleae, on segments 5
–
19 (15 pairs), each bearing two kinds of notochaetae; one short and winged from anterior row, bordered with serrations along distal portion, covered progressively with more spines from about middle to front of wing, on anterior surface; other long, stout, straight, tapering to pointed tip, covered progressively with more spines from mid-anterior portion to end, on anterior surface (
Figs 20A, D
;
21A
–
C
). Neuropodia, 12 pairs on segments 8
–
19, each with slightly raised torus
with transverse row of uncini; each uncinus with U-shaped anterior peg embedded into torus, several rows of minor teeth, and 4
–
5 longitudinal rows of major teeth, each with 6
–
7 teeth (
Fig. 21D
–
E
).
FIGURE 21.
Lagis
sp. Chaetae (AM W.30903): A–C. Close up of notochaetae, segment 11; D
–
E. Uncini, segment 11.
Scaphe broadly ovoidal, flattened dorsally, divided into six lobes on each lateral margin (
Fig. 20 D
–
E
). Anal flap contorted, probably the result of fixation (
Fig. 20 D
–
E
). Scaphal hooks eight pairs, amber, slightly curved and pointed tip, arranged in two transverse rows on dorsal margin of scaphe (
Fig. 20E
).
Tube not retained.
Distribution.
N
Queensland
(
Fig. 1
).
Habitat.
Soft sediments in shallow water.
Remark.
The specimen is broken near segment 11, and the body is contorted body. It belongs to the genus
Lagis
as it lacks a free cephalic veil which is connected to the opercular lateral margin at the base of 1
st
pair of tentacular cirri on segment 1, and chaetae on segments 20-21; it has 12 cirri on the rim of cephalic veil, smooth opercular margin and 4
–
5 longitudinal rows of major uncinial teeth. It differs from
L. portus
n. sp.
as this single specimen has 14 pairs of paleae and eight pairs of scaphal hooks. The specimen is very similar to
L. plurihamus
Choi, Jung & Yoon, 2017
, with regards to the arrangement of scaphal hooks, the shape of the scaphe and the presence of branchiae, but differs in having uncini with 4
–
5 longitudinal rows of major uncinial teeth and stout paleae. As the anal flap and anterior end of this specimen have been damaged, it is not possible to identify to species, but it differs from
Lagis portus
n. sp.
This specimen almost certainly represents another undescribed species from
Australia
(see Table 2), but additional material is required before it can be completely described.