Revision of Angursa (Arthrotardigrada: Styraconyxidae) with the description of a new species from Japan
Author
Fujimoto, Shinta
E030A1DD-9E91-48D9-93DD-D98F0BDFC87A
shinta.f@water-bears.com
Author
Hansen, Jesper Guldberg
3A2D97D6-689E-4E5E-9B57-1F5523B50F2B
Section of Biosystematics, Zoological Museum, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK- 2100 Copenhagen Ø, Denmark.
jesperguldberg@gmail.com
text
European Journal of Taxonomy
2019
2019-03-28
510
1
19
journal article
10.5852/ejt.2019.510
08fe4f6b-5422-45af-bc2e-29ad35fed42f
2118-9773
2616378
BF58E108-2C6C-4A80-BD7D-47FEF5805B06
Angursa lanceolata
Renaud-Mornant, 1981
Fig. 4
Emended diagnosis
Angursa
with bulbous primary clavae terminating in apices shorter than lateral cirri; pedestals of primary clavae and lateral cirri present; flat secondary clavae present; morphology of tertiary clavae unknown; lance-like cirri E; Leg I sensory organs present; legs II and III sensory organs absent; leg IV sensory organs each as elongate papilla with short apical spine; anal papillae absent.
Fig. 4.
Micrographs of
Angursa lanceolata
Renaud-Mornant, 1981
paratype.
A
. Cephalic region.
B
. Caudal region with leg IV sensory organ terminating in short, apical spine (white arrowheads).
Material examined
Paratype
ATLANTIC OCEAN
•
1 adult
; mounted with the dried out holotype;
Dinet
leg.;
AE128
.
Remarks
The primary clavae were described as leaf-shaped by
Renaud-Mornant (1981)
, but the primary clavae of the
paratype
we observed were bulbous papillae (8 μm long, 6 μm in diameter) with blunt apices (the apex were only recognised in one of the clavae) (
Fig. 4A
). Their neighbouring sensory organs, the lateral cirri (17 μm) (
Fig. 4A
), were apparently longer than reported in the original description (11 μm) (
Renaud-Mornant 1981
). As it was drawn in the original description, the pedestals that support the primary clavae and the lateral cirri were apparent (
Fig. 4A
). We recognised the flat secondary clavae (
Fig. 4A
) which had already been mentioned as slightly hollow formations by
Renaud-Mornant (1981)
, but their contours were difficult to observe. The presence and morphology of the tertiary clavae could not be revealed in this study. The characteristic cirri E (
Fig. 4B
) were confirmed, but their proportion seem slightly different that the drawing provided by
Renaud-Mornant (1981)
. We recognised the short, apical spines of the leg IV sensory organs (
Fig. 4B
) which were overlooked in the original description (
Renaud-Mornant 1981
). Other measurements of the
paratype
are as follows: body length. 136 μm; median cirrus, 3 μm; internal cirrus, 6 μm; external cirrus, 6 μm; cirrus E, 11 μm; leg I sensory organ, 6 μm; leg IV sensory organ, 5 μm.
Angursa lanceolata
closely resembles
A. lingua
by the bulbous primary clavae shorter than the lateral cirri, the apparent pedestals that support these two sensory organs, and the elongate leg IV sensory organs with apical spines (
Renaud-Mornant 1981
;
Bussau 1992
). However, these two species are easily distinguished from each other by the longer cephalic cirri and cirri E in
A. lingua
(median cirrus, 10 μm; internal cirrus, 9 μm; external cirrus 13 μm; lateral cirrus 28 μm; cirrus E, 20 μm (body length, 145 μm)) and by the lance-shaped cirri E in
A. lanceolata
versus tongue-shaped cirri E in
A. lingua
(
Renaud-Mornant 1981
;
Bussau 1992
).