An annotated checklist of the main representatives of meiobenthos from inland water bodies of Central and Southern Vietnam. I. Roundworms (Nematoda)
Author
Gusakov, Vladimir A.
Author
Gagarin, Vladimir G.
text
Zootaxa
2017
4300
1
1
43
journal article
32584
10.11646/zootaxa.4300.1.1
7eb2410e-8578-432a-88f8-bc129d0a5b08
1175-5326
837117
5FA0C659-9C52-4ABB-9CB6-1FB5CDDDF9F8
Family
Qudsianematidae Jairajpuri, 1963
66.
*
Chrysonema distinctum
(Jana & Baqri, 1985)
Andrássy, 1990
—
{50} (0, 4, 0, 0;
1
)
Population structure and abundance.
Ten juveniles and
16 females
(10
x10 3
/m2).
Ecology
and distribution.
Possibly
an amphibiont.
The
species of this genus parasitize roots of plants, including aquatic macrophytes (
Gagarin
2001
).
Rare
species.
Previously
not recorded outside
India
(
Vinciguerra
2006
).
Remarks.
Males are unknown (
Andrássy 1990
).
67.
*
Chrysonema limigenus
(Siddiqi, 1969)
Andrássy, 1990
—
{29} (0, 4, 0, 0;
1
)
Population structure and abundance.
Three juvenile specimens, one gravid female and two males (qualitative sample).
Ecology and distribution.
Ecology similar to the species described above. Previously reported only from
India
(Asia),
Poland
(Europe) and Surinam (
South
America) (
Vinciguerra 2006
).
68.
*
Crassolabium
Yeates, 1967
sp.—
{68} (0, 0, 0, 9;
1
)
Population structure and abundance.
Two juvenile specimens and one female.
Ecology and distribution.
Representatives of this genus mainly inhabit diverse terrestrial biotopes, but some occur in the water as well (
Peña-Santiago & Ciobanu 2011
).
Remarks.
Two species from forest soils are known in
Vietnam
:
C. aenigmaticum
Vu, Ciobanu, Abolafia & Peña-Santiago, 2010
and
C. vietnamense
Vu, Ciobanu, Abolafia & Peña-Santiago, 2010
(
Vu
et al.
2010
). The specimens we found resemble the widespread
C. ettersbergense
(de Man, 1885) Peña-Santiago & Ciobanu, 2008
but we could not observe all the morphological details in the single adult female found. Our specimen clearly differs from
C. aenigmaticum
and
C. vietnamense
by smaller body size, odontostyle and in some other characteristics.
69.
*
Epidorylaimus leptosoma
(
Altherr, 1963
) Andrássy, 1986
—
{55, 59, 66, 69, 70} (0, 0, 15, 27;
7
)
Population structure and abundance.
2 to
3 juveniles
and 2 to
14 females
at each site (up to 6
x10 3
/m2).
Ecology
and distribution.
Most
likely an amphibiont.
Rare
species.
Found
in soil in
Europe
(
Switzerland
) and, until this study, not noted anywhere else (
Altherr
1963
;
Vinciguerra
2006
). In
Vietnam
, found only in small forest water bodies.
70.
*
Labronemella papillata
(
Khan, Ahmad & Jairajpuri, 1995
) Gusakov & Gagarin, 2015
— {50, 66} (0, 4, 0, 9;
3
)
Population structure and abundance.
At site 50—a large number (over 50) of juveniles, 12 females and 12 males (28
x10 3
/m2); at the second locality—only one male.
Ecology and distribution.
Amphibiont. Described from soil in India (
Khan
et al.
1995
), but our finding a large population in one of the Vietnamese water bodies indicates the ability of this species to occupy aquatic environments as well. Until recently, recorded only from India (
Vinciguerra 2006
).
Remarks.
Initially, this species was assigned to the genus
Labronema
Thorne, 1939
as
L. papillatum
Khan, Ahmad & Jairajpuri 1995
(
Khan
et al.
1995
). Later,
Andrássy (2009b)
transferred it to
Crassolabium
based on the fact that females of
L. papillatum
have a transverse vulva, a characteristic of the genus
Crassolabium
(in
Labronema
,
the vulva is longitudinal). However, Andrássy did not consider the presence of inner liplets in this species, which are absent in the species of
Crassolabium
. Indeed, the presence of inner liplets and a transverse vulva are distinctive features of the genus
Labronemella
(
Andrássy 2009b
)
. On this basis, after analyzing the Vietnamese material we considered
Crassolabium papillatum
(
Khan, Ahmad & Jairajpuri 1995
) Andrássy, 2009
as a species of
Labronemella
(Gusakov & Gagarin 2015b)
.