Laubieriopsis cf. brevis ( Hartman , 1965)
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publication ID |
https://doi.org/ 10.1080/00222933.2010.540046 |
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persistent identifier |
https://treatment.plazi.org/id/03E787D5-FFE4-FFAA-83B3-FC4D360CF80B |
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treatment provided by |
Carolina |
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scientific name |
Laubieriopsis cf. brevis ( Hartman , 1965) |
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Laubieriopsis cf. brevis ( Hartman, 1965) View in CoL
( Figures 1 View Figure 1 , 2A, B View Figure 2 , 4 View Figure 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 View 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 View Figure 4 ).
Anterior region with four short chaetigers ( Figure 2B View Figure 2 ).
Middle region with 11 chaetigers, longer than anterior ones ( Figure 2B View Figure 2 ).
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 View Figure 4 ).
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 View Figure 2 , 4G, H View Figure 4 ). Small interramal papilla between notopodia and neuropodia, located near notopodia ( Figures 2A, B View Figure 2 , 4G, H View Figure 4 ).
Paired genital papillae anterior to chaetae 7 ( Figure 2B View Figure 2 ).
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 View Figure 2 , 4E, F View Figure 4 ). 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 .
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