Polycirridae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia
Author
Nogueira, João Miguel Matos
Author
Hutchings, Pat
Author
Carrerette, Orlemir
text
Zootaxa
2015
4019
1
437
483
journal article
10.11646/zootaxa.4019.1.17
7da86efa-d94d-4886-aabf-0395371356d9
1175-5326
245062
991FD209-84FF-4074-A175-E74570B53163
Polycirrus brutus
n. sp.
(
Fig. 21
)
Type
material.
Holotype
:
NTM
W.
023152
, Palfrey Island,
14°41'28.572"S
,
145°26'29.940"E
,
10 m
, coll. Coleman & Smith,
9 Apr 2008
, apparently complete specimen, in four pieces, some centimetres long, not measured due to state of preservation.
Paratype
: AM W.47691, CReefs, LI-10-021, Mrs Watson Beach,
14°39'41"S
,
145°22'27"E
,
10 m
.
Description.
Transverse prostomium attached to dorsal surface of upper lip; prostomium projecting laterally as one deeply grooved, tentacular prostomial process at each side; basal part as thick crest across dorsum, extending laterally and posteriorly, covering segment 1 laterally and terminating lateral to lower lip; poorly developed distal part, at base of upper lip, also extending along prostomial lateral processes (
Fig. 21
A–E). Few buccal tentacles remaining, of two
types
, short tentacles uniformly cylindrical, long ones slightly spatulated at tips (
Fig. 21
A–E). Peristomium forming lips; elongate and narrow upper lip, distinctly longer than wide, convoluted; small, button-like lower lip (
Fig. 21
A–E). Segment 1 only conspicuous mid-dorsally; segment 2 reduced, visible all around; body of uniform width and segments progressively longer until segment 10, then abruptly tapering to uniformly cylindrical posterior body, beginning from the termination of notopodia; large anterior abdominal segments, with thin body wall and poorly marked segmentation, posterior body with clearly defined, compacted segments (
Fig. 21
A–F). Slightly papillated, poorly defined ventro-lateral pads, present on segments 3–15, last pairs smaller (
Fig. 21
A–B, D). Notopodia extending for 13 segments at least (depending on the specimen being complete anteriorly), until segment 15; distinctly elongate, bilobed notopodia, lobes of equal size, first pair shorter (
Fig. 21
A–E).
Paratype
(complete, gravid) with 16 pairs of notopodia. Pinnate notochaetae in both rows (
Fig. 21
G–H), those from posterior row only pinnate at tips. Beginning of neuropodia unclear due to state of preservation of specimen, but apparently neuropodia only beginning after termination of notopodia, as thin, elongate pinnules (
Fig. 21
A, F).
Paratype
with neuropodia beginning immediately after the last pair of notopodia. Uncini intermediate between
types
1 and 2, with short neck, but otherwise as
type
2 (
Fig. 21
G). Large nephridia, visible by transparency through body wall; nephridial and genital papillae present on segments 3–15, anterior and ventral to bases of notopodia (
Fig. 21
A–B, D). Pygidium smooth to crenulated, with rounded ventral papilla (
Fig. 21
A, F).
Remarks.
The
holotype
of
P. brutus
n. sp.
is a specimen broken in four pieces, with both anterior and posterior ends. It seems to be complete, but there is great difference in width between fragments and perhaps a piece with few anterior segments is missing. The specimen has prostomium only at base of upper lip; button-like lower lip; slightly papillated, poorly defined ventro-lateral pads; 13 pairs of notopodia (16 pairs in
paratype
), with neuropodia beginning immediately after the termination of notopodia, so noto- and neuropodia do not occur simultaneously on any segment. Notopodia bear pinnate chaetae in both rows and neuropodia have
type
2 uncini with remarkably short neck for this
type
of uncini. Nephridial and genital papillae are present at the bases of all notopodia.
However, the most distinctive character of this specimen is the prostomium continuing laterally by one pair of long, deeply grooved tentacle-like extensions, like a pair of horns pointing posteriorly. The upper lip of
P. brutus
n. sp.
is also remarkable, distinctly longer than wide, convoluted, resembling that of some telothelepodids (Nogueira
et al.
2010, 2013).
FIGURE 21.
Polycirrus brutus
n. sp.
, holotype NTM W.023152. A. Entire worm, ventral view (fragments arranged to simulate the animal is entire); B–C. Anterior end, ventral and dorsal views, respectively; D–E. Close ups of the anterior end, ventral and dorsal views, respectively; F. Posterior end, left dorso-lateral view; G–H. Progressively higher magnifications of the notochaetae of segment 14; I. Uncini, mid-abdominal segment. Numbers refer to segments. Abbreviations: ll = lower lip, P = basal part of prostomium, PLP = prostomial lateral process, ul = upper lip, * = distal part of prostomium. Scale bars: A = 1.5 mm, B–F = 0.5 mm, G = 30 µm, H = 15 µm, I = 10 µm.
The only other known species of
Polycirrus
with similar horn-like prostomial lateral extensions is
P. nonatoi
Carrerette & Nogueira, 2013
, which also has longer than wide upper lip. Members of these species differ, however, because among members of
P. nonatoi
the tentacle-like prostomial extensions are shorter, with shallower groove; the distal part of prostomium extends along the upper lip until near the anterior margin of the lip; the lower lip is distinctly larger, rounded, cushion-like across the ventrum, reaching the anterior margin of segment 4 midventrally; the ventro-lateral pads are clearly defined and highly papillated; notopodia have elongate post-chaetal lobe and bear narrowly-winged chaetae in the anterior row of notochaetae; and, although the original description states that members of
P. nonatoi
have
type
1 uncini, these structures are intermediate between
types
1 and 2, with strongly bent back and relatively short heel, but otherwise as
type
2, although much shorter than those of other taxa with this
type
of uncini (Carrerette & Nogueira 2013). The
holotype
of
P. brutus
n. sp.
, on the other hand, has more typical
type
2 uncini, although still intermediate between
types
1 and 2, with a distinctly short neck for this
type
of uncini.
Although the prostomium is far less developed, not forming tentacular extensions,
P. coccineus
Grube, 1870
also has prostomial lateral extensions and narrow and elongate upper lip. In addition to the absence of tentacular extensions, members of this species differ from
P. brutus
n. sp.
by having larger, cushion-like lower lip across ventrum; highly papillated, tessellated ventro-lateral pads; 20 pairs of notopodia, extending until segment 22, with longer post-chaetal lobe; and nephridial and genital papillae only present until segment 9 (Glasby & Hutchings 2014).
Etymology.
We attribute the name “
brutus
” to this species after the character
Brutus
, from the cartoon “Popeye the Sailor”, in reference to the pair of prostomial horn-like lateral extensions, which resemble the curved arms of a very strong man.
Habitat.
Coral rubble at
10 m
.
Type
locality.
Palfrey Island,
14°41'28.572"S
,
145°26'29.940"E
, Lizard Island, Great Barrier Reef,
Australia
.
Distribution.
Only known from the Lizard region.