New records of eutardigrades (Tardigrada) from Faial and Pico Islands, the Azores, with the description of two new species
Author
Fontoura, Paulo
Author
Pilato, Giovanni
Author
Lisi, Oscar
text
Zootaxa
2008
1778
37
47
journal article
10.5281/zenodo.182262
63642e86-410e-4b94-a2cb-4787f3c52296
1175-5326
182262
Macrobiotus almadai
sp. nov.
Fig. 1
Material examined:
53 specimens
and
15 eggs
:
3 specimens
mounted in polyvinyl lactophenol collected on Túnel da Caldeira (Faial Island);
1 specimen
and
1 egg
mounted in Hoyer’s medium from Parque Florestal (Faial Island);
33 specimens
(30 mounted in Hoyer’s medium and
3 in
polyvinyl lactophenol) and
12 eggs
from Lages do Pico (Pico Island);
16 specimens
and
2 eggs
mounted in Hoyer’s medium from Terras do Pico (Pico Island).
Type
repository:
Holotype
(slide No. 5220) and two eggs are deposited in the collection of Binda & Pilato (Museo del Dipartimento di Biologia Animale “Marcello La Greca”, Università di Catania).
Paratypes
are deposited in the collection of P. Fontoura (Department of Zoology and Anthropology, Faculty of Sciences, University of Porto).
Specific diagnosis:
Species belonging to
hufelandi
group. Cuticle smooth with some small pores (fine granulation present only on hind legs), eyes present; buccal tube narrow; buccal armature very simple with peribuccal lamellae and three dorsal and three ventral thin transversal ridges; bands of teeth not visible; pharyngeal bulb with apophyses, two macroplacoids and microplacoid; eggs with reticulated shell and processes shaped in the form of inverted goblets; reticular design delicate and very regular; terminal disc of processes with very small teeth visible only in some orientations.
Description of the
holotype
: Body length 340 μm, colorless, eyes present; cuticle smooth with some small circular and elliptical pores (fine granulation present only on hind legs). Buccal armature simple: only 10 peribuccal lamellae and a system of three thin dorsal and three ventral transversal ridges present. Bands of teeth not visible. Rigid buccal tube narrow, 32.4 µm long and 3.6 µm (
pt = 11.1
) wide externally (
Fig. 1A
). Stylet supports inserted on the buccal tube wall at 76.5 % of its length (
pt = 76.5
). Pharyngeal bulb with apophyses, two rod-shaped macroplacoids and microplacoid. First macroplacoid, with central constriction, 8.2 µm long (
pt = 25.3
), second 5.5 µm (
pt
=
17.0
), microplacoid 2.7 µm long (
pt = 8.3
). Placoid row length 16.6 µm (
pt
=
51.2
). Macroplacoid row length 14.0 µm long (
pt
=
43.2
).
Claws of
hufelandi
type
with accessory points on the main branches and smooth lunules (
Figs. 1B, D
). External and internal claws of the third pair of legs 9.6 µm (
pt = 29.6
) long and 9.5 µm (
pt
=
29.3
) respectively. Posterior claws of hind legs 10.9 µm (
pt = 33.6
) long.
Eggs laid free, spherical, with reticulated shell (
Figs. 1E, F
) and with processes in the shape of inverted goblets (
Figs. 1E, G
). Diameter without processes 69–78 µm, including them 74–86 µm. On circumference 23–27 processes were present (
86–110 in
hemisphere). Processes up to 5.9 µm high with basal diameter of 5.1–5.5 µm. Terminal disc, 3.8–5.5 µm in diameter, may appear smooth (
Figs. 1E, F
), but in some orientations it shows very small teeth (
Fig. 1G
). Egg shell with very regular, elegant, and homogeneous reticular design (
Figs. 1E, F
). Margins of meshes very thin and basal meshes slightly larger than others.
FIGURE 1.
A–G,
Macrobiotus almadai
sp. nov.
(holotype): A, bucco-pharyngeal apparatus; B and C, claws of the third pair of legs; D, claws of the hind legs; E, egg; F and G, details of the egg shell (arrow indicates the small teeth of the terminal disc). (Scale bar = 10 µm).
Remarks:
Paratypes
similar to
holotype
in both qualitative and morphometric characters. Smallest specimen 161 µm long, largest one 394 µm.
Re-examination of some specimens and eggs collected on Pico and St. Maria Islands (
Fontoura, 1985
) showed that they do not belong to
M. hufelandi
, as previously identified, and must be attributed to the new species
Macrobiotus almadai
sp. nov.
Etymology:
The new species is dedicated in honor to the coordinator of the Eco-Ethology Research Unit, Prof. Vitor Almada, in appreciation of his support to our studies on tardigrades.
Differential diagnosis:
Macrobiotus almadai
sp. nov.
belongs to the
hufelandi
group of species. Some species of this group have narrow buccal tube and no (or almost not visible) bands of teeth in the buccal cavity (
M. diversus
Biserov, 1990
;
M. madegassus
;
M. humilis
;
M. denticulus
and
M. ramoli
Dastych, 2005
).
M. almadai
sp. nov.
differs from them in some characters of the eggs and, in addition, from
M. diversus
,
M. madegassus
and
M. humilis
in having three separate dorsal ridges instead of a long single ridge; from
M. denticulus
in lacking a tooth in the anterior part of the buccal tube, and from
M. ramoli
in having the dorsomedian ridge very thin, and smooth lunules.
The new species differs from
M. hufelandi
in having narrower buccal tube (
Tab. 1
;
Figs. 1A
,
2A
); bands of teeth in the buccal cavity not visible; stylet supports inserted on buccal tube in more anterior position (
pt
=
76.5
in
M. almadai
sp. nov.
and
80–81
in
M. hufelandi
); slightly shorter macroplacoids (
Tab. 1
); slightly longer claws (
Tab. 1
); eggs with more delicate and regular reticular design and terminal disc of processes with smaller teeth (
Figs. 1E, G
,
2
B).
TABLE 1.
Measurements (in µm) of some structures of the holotype, the smallest and the largest measured specimens of
Macrobiotus almadai
sp. nov.
, of a paratype of
Macrobiotus sandrae
and of a specimen of
Macrobiotus hufelandi
collected in the locus typicus.
Characters
M. almadai
sp. nov.
M. sandrae
M. hufelandi
Holotype
Smallest Largest
specimen specimen
| Body length |
340 |
195 |
394 |
376 |
? |
| Buccal tube length |
32.4 |
20.8 |
34.9 |
37.3 |
34.5 |
| Buccal tube external width pt |
3.6
11.1
|
2.1
10.1
|
4.0
11.5
|
5.3
14.2
|
4.8
13.9
|
|
Stylets support insertion
pt
|
76.5
|
74.0
|
76.8
|
76.4
|
81.1
|
| First macroplacoid length pt |
8.2
25.3
|
4.6
22.1
|
8.9
25.5
|
10.5
28.2
|
9.3
27.0
|
| Second macroplacoid length pt |
5.5
17.0
|
3.1
14.9
|
6.2
17.8
|
7.3
19.6
|
6.7
19.4
|
| Microplacoid length pt |
2.7
8.3
|
1.5
7.2
|
2.8
8.0
|
2.6
7.0
|
2.4
7.0
|
| Placoid row length pt |
16.6
51.2
|
10.2
49.0
|
18.6
53.3
|
22.5
60.3
|
19.2
55.7
|
| Macroplacoid row length pt |
14.0
43.2
|
8.4
40.4
|
15.8
45.3
|
19.1
51.2
|
16.4
47.5
|
| External claws II, III pt |
9.6
29.6
|
6.0
28.8
|
9.7
27.8
|
9.2
24.7
|
7.8
22.6
|
| Internal claws II, III pt |
9.5
29.3
|
5.9
28.4
|
9.6
27.5
|
8.0
21.5
|
?? |
| Anterior claws IV pt |
?? |
6.3
30.3
|
11.0
31.5
|
?? |
?? |
| Posterior claws IV pt |
10.9
33.6
|
?? |
?? |
?? |
?? |
M
.
almadai
sp. nov.
differs from
M. sandrae
in having narrower buccal tube (
Tab. 1
;
Figs. 1A
,
2
C); bands of teeth in buccal cavity not visible; slightly shorter macroplacoids (
Tab. 1
;
Figs. 1A
,
2
C); slightly longer claws (
Tab. 1
); egg shell with more delicate and regular reticular design (
Figs. 1F, G
,
2
D); terminal disc of processes with small teeth instead of jagged margin (
Fig. 2
D).