Revision of Biserovus xiae Li, Su & Yu, 2004 (Tardigrada: Macrobiotidae)
Author
Li, Xiaochen
text
Zootaxa
2009
2076
63
68
journal article
10.5281/zenodo.187234
0bc32df3-83bc-4c4d-926f-fb63e66b5a36
1175-5326
187234
Insuetifurca xiae
comb. nov.
(
Li, Su & Yu, 2004
)
Figs. 1
–7,
Table 1
Material examined:
Holotype
(Slide number 04/02/002) from Zhaobaoshan, Zhenhai County, Zhejiang Province,
China
. Additional material: three adults (Slide numbers Hi0704021, Hi0704023, Hi0704024) from the Five-Finger Mt. (18°52.920΄N, 109°39.698΄E) at
1200 m
above sea level, Hainan Province,
China
(
Li
et al
., 2008
). All specimens were mounted in Hoyer’s medium and deposited at the College of Life Sciences, Shaanxi Normal University.
Description:
Colorless, eyespots not visible (possibly dissolved after fixation), cuticle smooth without pores. Mouth antero-ventral with ten small peribuccal lamellae. Oral cavity armature well developed and composed of two bands of teeth in the posterior part of the cavity. First band of teeth is a row of small ridges parallel to the main axis of the buccal tube, slightly longer in the medial portion and just anterior to second band of teeth; second band of teeth consists of three transverse crests/ridges, divided into ventral and dorsal series. Buccopharyngeal tube consisting of a rigid anterior portion and a posterior flexible portion with spiral thickenings on the wall (
Figs. 1–2
, 5). Thin walled, buccal tube (rigid portion of bucco-phayngeal tube) with ventral lamina; buccal tube much longer than the pharyngeal tube. Pharyngeal tube with spiral thickenings, with screw threads disconnected. Stylet supports inserted close to the junction of buccal and pharyngeal tube. Stylet furcae well developed with the posterior processes arched and converging backwards. Pharyngeal bulb elliptical, with apophyses, three short-rod shaped macroplacoids and a microplacoid. Three macroplacoids equal in length, sometimes the second slightly shorter. The third macroplacoid with inward-projecting enlargement at the posterior end. Apophyses and microplacoid well developed.
Claws of a slightly modified
Macrobiotus
type
with the basal portion subdivided into a very short stalk and a large distal portion less sclerified than the common tract. Lunules thin and smooth. Accessory points well developed on the primary branches of all claws. Crescent-shaped cuticular bar present at the base of claws I–III (
Figs. 3–4
, 6–7). Claw sequence 2-1-1-2. Claws increasing in size from I to IV.
Remarks:
Measurements of all available specimens are given in
Table 1
. The specimens from Hainan are smaller than the
holotype
in body size.
Differential diagnosis:
Insuetifurca xiae
was originally assigned to the genus
Biserovus
(
Li, Su & Yu, 2004
)
.
Insuetifurca
differs from
Biserovus
by having lunules and by the peculiar shape of the stylet furcae, with the posterior process arched and converging backwards. The characters of the claws and the stylet furcae in
I. xiae
were misinterpreted in the original description (
Li, Su & Yu, 2004
). The erroneous assignment resulted from the poor quality of the microscope used.
Up to now the genus
Insuetifurca
contained only two species,
I. arrowsmithi
(
Kathman & Nelson, 1989
)
and
I. fujiense
(
Ito, 1997
) (
Guidetti & Pilato, 2003
)
.
I. xiae
comb. nov.
differs from
I. arrowsmithi
by having a much lower
pt
of the phayngeal tube and by the presence of crescent-shaped cuticular bars below claws I–III;
I. xiae
comb. nov.
differs from
I. fujiense
by having the macroplacoids equal in length or the second as the shortest instead of the macroplacoids increasing in length from the first to the third and by the presence of crescent-shaped cuticular bars below claws I–III.
FIGURES 1–4.
Insuetifurca xiae
comb. nov.
(Li, Su & Yu, 2004) (holotype): 1, buccal apparatus focused to show the furca; 2, buccal apparatus focused to show the peribuccal lamellae; 3, claws on the second pair of legs; 4, claws on the hind legs. Figures. 1–2: scale bar = 10µm; figures. 3–4: scale bar = 5µm.
FIGURES 5–7.
Insuetifurca xiae
comb. nov.
(
Li, Su & Yu, 2004
) (
holotype
): 5, buccal apparatus; 6, claws on the second pair of legs; 7, claws on the hind legs. Figure 5: scale bar = 10µm; figures. 6–7: scale bar = 5µm.
TABLE 1.
Measurements of
Insuetifurca xiae
comb. nov.
(Li, Su & Yu, 2004). Abbreviations: PBL = primary branch length; SBL = secondary branch length.
Character
Holotype
Additional specimens (Hainan Province)
(Zhejiang Province)
| 04/02/002 μm pt |
Hi0704021 μm pt |
Hi0704023 μm pt |
Hi0704024 μm pt |
| Body length Buccal tube length |
368.6 31.3 |
202.8 26.0 |
208.0 23.4 |
221.0 24.7 |
| Buccal tube width |
4.7 15.02 |
3.9 15.0 |
3.6 15.56 |
3.6 14.57 |
| Phayngeal tube length Bucco-pharyngeal tube length |
10.4 33.23 41.8 |
10.4 40.0 36.4 |
10.4 44.44 33.8 |
9.1 36.84 33.8 |
| Stylet support insertion point |
28.7 91.69 |
23.4 90.0 |
20.8 88.89 |
22.1 89.47 |
to be continued.
TABLE 1.
(continued)
Character
Holotype
Additional specimens (Hainan Province)
(Zhejiang Province)
| 04/02/002 μm pt |
Hi0704021 μm pt |
Hi0704023 μm pt |
Hi0704024 μm pt |
| First macroplacoid length |
5.2 16.61 |
5.2 20.0 |
3.9 16.67 |
4.4 17.81 |
| Second macroplacoid length Third macroplacoid length |
5.2 16.61 5.2 16.61 |
4.9 19.0 5.2 20.0 |
3.6 15.56 3.9 16.67 |
4.2 17.0 4.4 17.81 |
| Macroplacoid row length |
18.2 58.15 |
15.6 60.0 |
13.0 55.56 |
13.0 52.63 |
| Microplacoid length Pharyngeal bulb length |
3.7 11.82?? |
2.9 11.15 31.2 120.0 |
2.6 11.11 31.2 133.33 |
2.6 10.53 33.8 136.84 |
| Pharyngeal bulb width |
?? |
26.0 100.0 |
26.0 111.11 |
27.3 110.53 |
| Leg 1 external claw PBL Leg 1 external claw SBL |
7.8 24.92 6.5 20.77 |
6.5 25.0 5.2 20.0 |
???? |
???? |
| Leg 1 internal claw PBL |
7.8 24.92 |
6.5 25.0 |
?? |
?? |
| Leg 1 internal claw SBL Leg 2 external claw PBL |
6.5 20.77 7.8 24.92 |
5.2 20.0 6.5 25.0 |
?? 6.2 26.5 |
???? |
| Leg 2 external claw SBL |
6.5 20.77 |
5.2 20.0 |
4.9 20.94 |
?? |
| Leg 2 internal claw PBL Leg 2 internal claw SBL |
7.8 24.92 6.5 20.77 |
6.5 25.0 5.2 20.0 |
6.2 26.5 4.9 20.94 |
???? |
| Leg 3 external claw PBL |
8.1 25.88 |
6.8 26.15 |
?? |
6.0 24.29 |
| Leg 3 external claw SBL Leg 3 internal claw PBL |
6.8 21.73 8.1 25.88 |
5.5 21.15 6.8 26.15 |
???? |
4.7 19.03?? |
| Leg 3 internal claw SBL |
6.8 21.73 |
5.5 21.15 |
?? |
?? |
| Leg 4 posterior claw PBL Leg 4 posterior claw SBL |
8.3 26.52 7.0 22.36 |
???? |
6.5 27.78 5.2 22.22 |
6.5 26.32 5.2 21.05 |
| Leg 4 anterior claw PBL |
8.3 26.52 |
?? |
6.5 27.78 |
?? |
| Leg 4 anterior claw SBL |
7.0 22.36 |
?? |
5.2 22.22 |
?? |
| Acknowledgments |
This study was supported by grants from the National Natural Science Foundation of
China
(No. 30770254). I sincerely thank Dr. Sandra Claxton for the English revision of the paper.