Abyssal Fauveliopsidae (Annelida) from the South East Atlantic
Author
Thiel, Daniel
Author
Purschke, Günter
Author
Böggemann, Markus
text
Journal of Natural History
2011
2011-04-04
45
15 - 16
923
937
http://dx.doi.org/10.1080/00222933.2010.540046
journal article
10.1080/00222933.2010.540046
1464-5262
4652385
Laubieriopsis
cf.
brevis
(
Hartman
,
1965)
(
Figures 1
,
2A, B
,
4
D–K)
Material examined
We examined 246 complete specimens, 14 anterior fragments, two middle fragments and five posterior fragments (listed in Appendix 2).
Diagnosis
Adult specimens with 16 chaetigers; four anterior chaetigers with two or three thinner and two or three broader spines per ramus; middle region with 12 chaetigers, each ramus with one acicular plus capillary chaeta; posterior region with one chaetiger, having one acicular and one long capillary chaeta per ramus, longer than other chaetae; paired genital papillae anterior to chaetae of chaetiger 7.
Distribution of examined material
Angola
, Cape and
Guinea
Basin;
3945–5494 m
(
Figure 1
).
Description
All completely developed specimens with 16 chaetigers; largest specimens up to
8.5 mm
in length,
0.7 mm
in width; body cylindrical, white-translucent, divided into three regions.
Prostomium and peristomium retractable, with ciliary field and nuchal organs (
Figure 4D,G,I
).
Anterior region with four short chaetigers (
Figure 2B
).
Middle region with 11 chaetigers, longer than anterior ones (
Figure 2B
).
Posterior region consisting of last chaetiger and pygidium; last chaetiger slightly shorter than those of middle region; pygidium with terminal anus surrounded by three large papillae, one on the upper and two on the lower side (
Figure 4J, K
).
Parapodia biramous, in anterior region nearly totally reduced to chaetae, with two or three thinner and two or three broader spines in each ramus, in middle region only represented by chaetae, with one capillary spine on the outer side and one acicular spine on the inner side of each ramus, slightly longer than anterior chaetae, in posterior region also totally reduced to chaetae, with one acicular and one capillary chaeta per ramus, slightly longer than those of the middle region; notopodial chaetae always slightly taller than neuropodial ones (
Figures 2B
,
4G, H
). Small interramal papilla between notopodia and neuropodia, located near notopodia (
Figures 2A, B
,
4G, H
).
Paired genital papillae anterior to chaetae 7 (
Figure 2B
).
Remarks
Juvenile specimens of
L
. cf.
brevis
with multiple-toothed chaetae, displaced during development by the chaetae of the adult from anterior to posterior, beginning at the neuropodia, followed at a distance of one to five chaetigers by the notopodia (
Figures 2A
,
4E, F
). Rami of middle and posterior region can have up to three chaetae during displacement.
Some of the completely developed specimens were carrying large eggs within the first third of the body.
Laubieriopsis
cf.
brevis
most likely feeds on sediment and detritus, as can be seen from the sediment-filled gut in the posterior third of several specimens.
Discussion
The specimens examined were named
Laubieriopsis
cf.
brevis
(
Hartman, 1965
)
, because the status of
L. brevis
seems to be uncertain and might be regarded as a species complex (
Petersen 2000
).
Laubieriopsis hartmanae
(
Levenstein, 1970
)
, originally described as
Fauveliopsis hartmani
Levenstein, 1970
, has been synonymized with
Laubieriopsis brevis
(
Hartman, 1965
)
by
Katzmann and Laubier (1974)
and
Levenstein (1975)
. Both taxa are obviously similar, but appear to differ in the number of genital papillae (
Petersen 2000
). Only one unpaired papilla was mentioned by J.A. Blake (personal communication in
Petersen 2000
) after re-examination of the
holotype
of the latter species, whereas a pair of genital papillae was found in all other closely investigated specimens (
Petersen 2000
). However, the second genital papilla might be retracted or overlooked and might not be totally developed in the
holotype
of
L. brevis
, especially because this structure “was difficult to see and could only be observed under oil immersion” (
Petersen 2000
). As the only difference that can be observed is the uncertain and questionable existence of an unpaired genital papilla, our material is provisionally assigned to
L
. cf.
brevis
. To clarify the status of
L. brevis
and
L. hartmanae
, type and non-type material of both species from several areas should be compared. However, this is beyond the scope of the present study. Furthermore, there is some confusion regarding
Laubieriopsis brevis
and
Fauveliopsis brevipodus
(
Hartman, 1967
)
.
Laubieriopsis brevis
, first described as
Brada brevis
by
Hartman (1965)
, was transferred to the genus
Fauveliopsis
by
Hartman and Fauchald (1971)
, whereas
Fauveliopsis brevipodus
was first described as
Fauveliopsis brevis
by
Hartman (1967)
and renamed
Fauveliopsis brevipodus
by Hartman (1971). Based on the number of 28 chaetigers, the species identified as
Fauveliopsis brevis
by
Levenstein (1970)
and
Cantone (1994)
belongs to
Fauveliopsis brevipodus
and not to
Laubieriopsis brevis
.