New records of Eutardigrada from Belarus with the description of three new species
Author
Pilato, Giovanni
Author
Kiosya, Yevgen
Author
Lisi, Oscar
Author
Sabella, Giorgio
text
Zootaxa
2012
3179
39
60
journal article
45532
10.5281/zenodo.279945
29ff95c8-b1d7-4cfa-966c-ca6bd1627974
1175-5326
279945
Hypsibius valentinae
sp. nov.
(
Fig. 9
)
Type
material.
Minsk Oblast, vicinity of Zhodino, pine forest (approximately 54°6ʹ N, 28°21ʹ E), moss on soil collected (
November 2008
) by S.A. Dobrovolsky:
holotype
and 55
paratypes
; moss on wood collected (
November 2008
) by S.A. Dobrovolsky: 19
paratypes
. Vitebsk Oblast, Sennensky district, Spruce forest, Vicinity of Margoitsy village (
54°40'19"N
,
29°37'27"E
); moss sample collected (
June 2002
) by G.O. Mazepa:
1 specimen
.
Type
repository.
Holotype
(slide No. 5436) and 21
paratypes
(slides No. 5426, 5427 and 5429) are deposited in the collection of Binda & Pilato (Museum of the Department of Animal Biology “Marcello La Greca”, University of Catania,
Italy
). Other specimens and exuvia are deposited in the collection of Kiosya (Kharkiv National University,
Ukraine
).
Specific diagnosis.
Cuticle smooth; eye spots present; two macroplacoids and a small septulum present; claws of the
Hypsibius
type
with slightly enlarged bases and accessory points on the main branches; small, smooth, flexible lunules present; a short cuticular bar was present between the bases of the claws of the hind legs; no cuticular bar on the first three pairs of legs.
Description of the
holotype
.
Body length 315 µm; colourless, cuticle smooth; cuticular pores and dots not visible. Eye spots present. Bucco-pharyngeal apparatus of the
Hypsibius
-
type
(
Fig. 9
A). Mouth subterminal without peribuccal lamellae; buccal cavity small without rings of teeth. Rigid buccal tube, without ventral lamina, 27.2 µm long and 2.0 µm wide (
pt
= 7.4); apophyses for the insertion of the stylet muscles hook-shaped; stylet supports inserted on the buccal tube at 62.2% of its length (
pt
= 62.2). Pharyngeal bulb with apophyses, two macroplacoids and a small septulum. Length of first macroplacoid 6.0 µm (
pt
= 22.1), second 4.4 µm (
pt
= 16.2), and septulum 1.4µm (
pt
= 5.1); entire placoid+septulum row 12.1 µm long (
pt
= 44.5); macroplacoid row length 10.9 µm (
pt
= 40.1).
Claws of the
Hypsibius
-
type
, well developed (
Fig. 9
B–E) with slightly enlarged base and accessory points present on the main branches. Due to the orientation, only some of the claws were measurable; external claws on the first and second pairs of legs 14.9 µm (
pt
= 54.8) and 16.4 µm long (
pt
= 60.3) respectively; posterior and anterior claws on the hind legs 17.2 µm (
pt
= 63.2) and 11.5 µm long (
pt
= 42.3) respectively. Small, smooth, flexible lunules, present but difficult to see (
Fig. 9
C, arrow;
Fig 9
E, arrow a); a short cuticular bar was present between the bases of the claws of the hind legs (
Fig. 9
E, arrow b); no cuticular bar on the first three pairs of legs. Smooth eggs laid in the exuvia.
Remarks.
The
paratypes
were similar to the
holotype
in qualitative and metric characters. (we referred to the
pt
index values when the specimens had different body length). The measurements of three specimens are presented in Table 4.
Etymology.
The specific name refers to the zoologist
Valentina Schevchenko
, our colleague from the Chernihiv National University (
Ukraine
).
Differential diagnosis.
Prior to this description of
Hypsibius valentinae
sp. nov.
, six species of
Hypsibius
were described with smooth cuticle, two macroplacoids and septulum:
H. iskandarovi
,
H. septulatus
,
H. heardensis
Miller, W.R., McInnes, & Bergstrom, 2005
,
H. seychellensis
,
H. dujardini
, and
H. pallidoides
. Comparing adults of, where possible, comparable size the new species can be from the other species (Table 4) as follows:
The new species differed from
H. iskandarovi
,
H. septulatus
and
H. heardensis
in lacking cuticular bars on the first three pairs of legs; in addition, it differed from
H. iskandarovi
in having eye spots; lacking a pseudoseptulum (
Figs. 9
A, B and 10A), and had shorter claws (the
pt
index relative to the posterior claws of the hind legs about
63 in
Hypsibius valentinae
sp. nov.
,
75.4–95.3 in
H. iskandarovi
according to
Tumanov, 1997
).
The new species also differed from
H. septulatus
in lacking cuticular undulations; having a slightly narrower buccal tube; smaller septulum (Table 4;
Figs. 9
A and 10C), and in having lunules.
It also differed from
H. heardensis
in having eye spots and lunules.
The new species differed from
H. pallidoides
by having stylet supports inserted on the buccal tube in a more caudal position (pt =
61.3–62.5 in
H. valentinae
sp. nov.
,
54.2–55.2 in
H
.
pallidoides
); slightly longer placoids and septulum; external claws very different in shape as the claws of
H
.
pallidoides
were of the
pallidus
type
(i.e. with the main branches inserted on the internal branches more distant from the base) (
Figs 9
C–D and 11A); and in having lunules.
Hypsibius valentinae
sp. nov.
differed from
H. seychellensis
in having slightly wider buccal tube (Table 4); smaller septulum; longer claws (Table 4), and in having lunules (
Figs. 9
C, arrow, ad 11B).
FIGURE 9.
Hypsibius valentinae
sp. nov.
A, bucco-pharyngeal apparatus of the holotype (slide No. 5426). The arrow indicates the small septulum. B, Claws of the first pair of legs of the holotype. C, Claws of the second pair of legs of a paratype (slide No.5426) (arrow indicates the small lunula of the external claw). D, Claws of the third pair of legs of the same paratype. E. Claws of the hind legs of a paratype (slide No.5426) (arrow ‘a’ indicates the lunula of the anterior claw; arrow ‘b’ indicates the cuticular bar between the claws). (Scale bars = 10 µm).
FIGURE 10.
A, B,
Hypsibius iskandarovi
(paratype, slide No. 4334): A, Bucco-pharyngeal apparatus (the arrow indicates the pseudoseptulum). B, Claws of the hind legs. C, D,
Hypsibius septulatus
(holotype, slide No. 4780): C, Bucco-pharyngeal apparatus. D, Claws of the third pair of legs (the arrow indicates the cuticular bar near the internal claw basis. (Scale bars = 10 µm).
The new species differed from
H. dujardini
in having the buccal tube of the same width in the anterior and posterior portion, while in
H. dujardini
the width of the buccal tube gradually increases; smaller septulum (Table 4;
Figs. 9
A and 11D), and in having lunules.
Hypsibius valentinae
sp. nov.
had a small septulum,
Hypsibius allisoni
had a very small microplacoid; considering the dimensions of these structures and, sometimes, the difficulty in distinguishing between a microplacoid and a septulum in these species, we think it opportune to stress that
H. valentinae
sp. nov.
also differed from
H. allisoni
in having different claw shape as the main branch of external claws was inserted on the secondary branch in a more distal position (
Figs. 9
B–E and 11C); in having small lunules and a cuticular bar between the bases of the claws on the hind legs.
Very probably
Hypsibius convergens
sensu
stricto
lacks both microplacoid and septulum, but some authors attributed to this species specimens that have a small microplacoid and, due to the possibility of confusion between microplacoid and septulum, it cannot be excluded that at least some of those specimens will have a septulum. In this case, it would be necessary to ascertain whether they belong to
H. valentinae
sp. nov.
as, in our opinion, such specimens cannot be attributed to
H. convergens
. In any case,
Hypsibius valentinae
sp. nov.
differed from
H. convergens
in having lunules and the common portion of the claws longer, slender and with the basal extremity less expanded.