Revision of Leocrates Kinberg, 1866 and Leocratides Ehlers, 1908 (Annelida, Errantia, Hesionidae)
Author
Salazar-Vallejo, Sergio I.
text
Zootaxa
2020
2020-02-18
4739
1
1
114
journal article
23993
10.11646/zootaxa.4739.1.1
d3e60fb6-636b-4e03-b55a-0e910f9a468e
1175-5326
3672547
544B9C82-BF33-4EA1-9411-E1A307137466
Paraleocrates djangkarensis
(Augener & Pettibone
in
Pettibone, 1970
)
n. comb.
Figure 61
Leocrates djangkarensis
Augener & Pettibone
in
Pettibone, 1970: 227–229
,
Figs 25–26
.
Leocrates chinensis
:
Horst 1924: 193
(
partim,
Sta. 105) (
non
Kinberg, 1866
).
Type material
.
Philippines
.
Holotype
(
ZMA
V. Pol.
534.3), Sulu Islands, off
NE
Gujangan Island
, R
/
V Siboga
, Sta. 105 (
06°08’ N
,
121°19’ E
),
275 m
, dredge, coral,
4 Jul. 1899
.
Indonesia
,
paratype
(
ZMA
V. Pol.
2104), off
Djangkar
,
Java
Island, R
/
V Siboga
,
Sta.
5 (
07°46’ S
,
114°30.5’ E
),
330 m
, deep-sea trawl, muddy bottom,
10 Mar. 1899
(used for variation).
Description
.
Holotype
(ZMZ V. Pol. 534.3), complete, slightly distorted, dehydrated, most body cirri missing (
Fig. 61A
). Body obconic, wider anteriorly, tapered posteriorly,
12 mm
long,
2 mm
wide, 16 chaetigers; right parapodium of chaetiger 3, and left parapodia of chaetigers 3, 8, 9, and 14 previously removed (three ones removed by Pettibone in a small vial, others missing); a slightly lateral anteroventral dissection for observing pharynx features previously made. Body brownish, venter with two wide longitudinal brown bands (
Fig. 61C
), leaving a paler midventral region (purple in recently preserved specimens after Horst).
Prostomium slightly wider than long, slightly wider anteriorly (
Fig. 61B
). Lateral antennae with ceratophores distinct, left one corrugated, right one missing, slightly longer than left palp (right palp distorted, directed laterally); palpophore 2–3 times longer than palpostyles. Median antenna missing, scar inserted centrally, between eyes. Eyes barely pigmented, round, anterior ones twice larger and slightly more distant to each other than posterior ones. Lateral peristomial tubercles round, as long as wide.
FIGURE 61
.
Paraleocrates djankarensis
(Augener & Pettibone
in
Pettibone, 1970
)
,
new combination
, holotype (ZMA V. Pol. 534.3). A. Dorsal view. B. Anterior region, dorsal view. C. Anterior region, ventral view. D. Chaetiger 3, left parapodium, anterior view, MGS (inset: lower neurochaetal blade). E. Chaetiger 8, left parapodium, anterior view, MGS (insets: lower neurochaetal blades). Scale bars: A: 1.4 mm, B: 0.6 mm, C: 0.8 mm, D: 0.2 mm, E: 0.4 mm.
Nuchal organs lobes horizontal C-shaped, completely concealed by anterior margin of tentacular belt; lateral ciliated bands visible dorsally. Tentacular cirri almost completely missing, one ventral cirrus without tip reaching chaetiger 3. Lateral cushions low, projected, most tripartite; longitudinal striae visible.
Pharynx not exposed; jaws observed through previous dissection. Lateral vesicles not seen. Anterior margin with about 20 irregular constrictions. Dorsal and ventral jaws single, fang-shaped brownish, exposed, tapered, ventral jaw smaller than dorsal one.
Peristomial dorsolateral tubercles as long as wide, slightly projected anteriorly, smooth.
Dorsal cirri broken, some remaining shorter than body width. Chaetigers 1–3 without notochaetae (
Fig. 61D
); notochaetae present along chaetigers 4–16, about 30 per bundle, delicate, arranged in bundles, notochaetal surface smooth. Notacicular lobes tapered, blunt; neuracicular lobes projected, blunt, as long as wide (
Fig. 61E
). Ventral cirri surpassing neurochaetal lobes. Neurochaetae about 30 per bundle, decreasing in size ventrally, blades unidentate, 4–65 times longer than wide, guards projected beyond tooth as long aristae, tooth slightly falcate (
Fig. 61D, E
, insets).
Posterior region tapered, almost without cirri. Prepygidial segment with dorsal cirrophores 4–5 thicker than ventral ones. Pygidium with anus terminal, anal cirri missing.
Oocytes not seen.
Variation
.
Paratype
(ZMA V. Pol. 2104) damaged, soft, brownish. Body
35 mm
long,
3 mm
wide, 16 chae- tigers; cirri and many chaetae missing; left parapodia of chaetigers 4 and 6, and right parapodia of chaetigers 9 and 10 previously removed. An anteroventral dissection for observing pharynx features previously made. Notopodia from chaetiger 4, most notochaetae missing, a few remaining, smooth. Neuropodia with a few chaetae remaining (7–15), blades unidentate, most straight, a few bent dorsally, guards projected far beyond tip of tooth.
Remarks
.
Paraleocrates djankarensis
(Augener & Pettibone
in
Pettibone, 1970
)
is newly combined into
Paraleocrates
by having unidentate blades, as opposed to bidentate blades present in
Leocrates
, as herein restricted.
Paraleocrates djankarensis
differs from the other species in the genus,
P. wesenberglundae
(
Pettibone, 1970
)
n. comb.
from the Gulf of
Oman
, in the size of eyes and in the
type
of neurochaetal blades. In
P. djankarensis
anterior eyes are twice larger than posterior ones, and neurochaetal blades are unidentate, with teeth round and have long, aristate guards, whereas in
P. wesenberglundae
eyes are of similar size, and neurochaetal blades have no guards at all, but their teeth are tapered but without aristae.
The
paratype
has neurochaetal blades slightly different because instead of having slightly falcate tooth, as in the
holotype
, it is rather straight, and even bent dorsally; because of the poor condition of the specimen, no other differences were found and consequently it is regarded as conspecific pending the finding of better specimens.
Distribution
.
Philippines
and
Indonesia
, in mixed or muddy bottoms at
275–330 m
depth.