Four new species of the Diphascon nobilei group (Eutardigrada, Hypsibiidae)
Author
Pilato, Giovanni
Author
Binda, Maria Grazia
Author
Bertolani, Roberto
Author
Lisi, Oscar
text
Journal of Natural History
2005
2007-02-21
39
14
1029
1041
http://dx.doi.org/10.1080/00222930400001590
journal article
10.1080/00222930400001590
1464-5262
5214258
Diphascon (D.) platyungue
sp. n.
(
Figure 4
;
Table I
)
Material examined
Marche
:
Mt Vettore
(Ascoli):
Shelter Zilioli
(
2250 m
):
holotype
(slide N. 4926) and
three paratypes
in meadow; Zilioli cross (
2150 m
) (
three specimens
in meadow)
;
Latium
:
Sabaudia
(Latina) (
three specimens
from mosses on sand dunes in pine-wood)
.
Description of the
holotype
Body length 194
M
m, colourless, eyes absent, cuticle smooth without pearls. Buccopharyngeal apparatus shown in
Figure 4A
. The bucco-pharyngeal tube, measured as indicated in the description of
D. serratum
, is 45.2
M
m long; the rigid buccal tube 20.8
M
m long (
pbf
546) and 1.7
M
m wide (
ptd
58.2). The stylet supports are inserted on the bucal tube at 62.9% of its length (
ptd
562.9). The pharyngeal bulb (27.4
M
m × 19
M
m) has small apophyses, three rod-shaped macroplacoids and microplacoid, the septulum is absent. The entire placoid row is 16.1
M
m in length (
ptd
577.4) including the microplacoid, 14.1
M
m (
ptd
567.8) excluding it. The first macroplacoid is 3.8
M
m in length (
ptd
518.3), the second 3.6
M
m (
ptd
517.3), the third 5.7
M
m (
ptd
527.4), microplacoid 1.7
M
m (
ptd
58.2).
Figure 4.
Diphascon (D.) platyungue
sp. n.
(A) Bucco-pharyngeal apparatus; (B) claws of the third pair of legs; (C) claws of the fourth pair of legs; (D) claws of the second pair of legs of a paratype. Scale bar: 10
M
m.
The claws (
Figure 4B–D
) have accessory points on the main branches. The claws of the hind legs (
Figure 4C
), particularly of the posterior claws, have the basal portion extremely enlarged; their branches are short; the indented basal margin of both internal and external claws appear prolonged in one medial and one lateral thickening. On the first three pairs of legs (
Figure 4B, D
) the external claws have an indented basal margin, the internal claws have a smooth basal margin. The internal claws are 6.1
M
m long (
ptd
529.3) on the second and third pairs of legs, the external claws of the same pairs of legs are not measurable due to their unfavourable orientation (in other specimens the value of the
ptd
index relative to these claws is 36–39.3); on the hind legs the anterior claws are 6.5
M
m long (
ptd
531.2) and the posterior claws 8.5
M
m long (
ptd
540.9). A cuticular bar is present near the internal claws on the first three pairs of legs.
Eggs not found.
The
paratypes
are similar to the
holotype
. In
Table I
the dimensions of some structures of the smallest and of the largest measured specimens are indicated.
Etymology
The name
platyungue
refers to the shape of the basal portion of the hind legs.
Remarks
Diphascon platyungue
sp. n.
differs from
D. nobilei
in having claws shorter with respect to the buccal tube length (
Table I
), claws of the hind legs with a wider basal portion, internal claws on the first three pairs of legs without basal spines.
The new species differs from
D. serratum
in having the stylet supports inserted on the buccal tube in a more cephalic position (
Table I
), narrower buccal tube, shorter placoids (
Table I
), claws of the hind legs with a wider basal portion.
The new species differs from
D. nelsonae
in the following features: slightly longer buccal tube and, as a consequence, lower values of the
ptd
index relative to placoid row and to the claw length (
Table I
); claws shorter and less slender with shorter secondary branches, claws of the hind legs with a clearly larger basal portion (
Figures 3
,
4
).