Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana
Author
Pešić, Vladimir
Author
Smit, Harry
text
Zootaxa
2014
3820
1
1
80
journal article
36832
10.11646/zootaxa.3820.1.1
e3d7d016-1d73-438f-95e4-1b028b2b9627
1175-5326
286303
BBE4177B-5A2C-4911-987C-454BB8FA767C
Monatractides
cf.
ventriosus
(
K. Viets, 1916
)
(
Figs. 23A–E
,
24A–D
,
25H–I
,
26H–I
,
44D
,
Tab. 3
)
Atractides ventriosus
K. Viets 1916
: 263
.
New records
.
Ghana
: Unnamed stream between Apepem and Kojo Amu, Atewa Hills, 6º
10.252 N
, 0º
36.520 W
, alt.
424 m
asl.,
27.ii.2013
, Smit, 0/1/0; Kue River, Kyabobo NP, 8º
31.087 N
, 0º
36.049 E
, alt.
208 m
asl.,
25.ii.2013
, Smit, 0/1/0; Laboun River, downstream, Kyabobo NP, 8º
19.931 N
, 0º
34.476 E
, alt.
303 m
asl.,
24.ii.2013
, Smit, 1/ 0/0 (mounted); Laboun River, downstream of falls, Kyabobo NP, 8º
19.836 N
, 0º
35.487 E
, alt.
342 m
asl.,
24.ii.2013
, Smit, 1/3/0 (1/1/0 mounted); Ankasa River, Ankasa NP, 5º
13.011 N
, 2º
39.126 W
, alt.
60 m
asl.,
13.ii.2013
, Smit, 0/1/0; Afiaso stream, Kakum NP, 5º
30.087 N
, 1º
26.373 W
, alt.
114 m
asl.,
12.ii.2013
0/1/0; Agumatsa River at first bridge, Agumatsa Wildlife Sanctuary, 7º
06.830 N
, 0º
35.760 E
, alt.
253 m
asl.,
22.ii.2013
, Smit, 0/1/0 (mounted); Unnamed creek upstream Sagyimase, Atewa Hills, 6º
13.966 N
, 0º
33.114 W
, alt.
671 m
asl.,
28.ii.2013
, Smit, 0/9/0; Ankasa Exporation Base stream, Ankasa NP, 5º
16.413 N
, 2º
38.810 W
, alt.
81 m
asl.,
14.ii.2013
Smit, 0/1/0; Nubui River, Agumatsa Wildlife Sanctuary, 7º
06.986 N
, 0º
35.548 E
, alt.
254 m
asl.,
22.ii.2013
, Smit, 1/3/0; Akaa Falls, 6º
10.516 N
, 0º
11.723 W
, alt.
180 m
asl.,
9.iii.2011
, Smit, 0/2/0.
Morphology.
General features
—Idiosoma roundish; shoulder platelets elongated (shoulder/frontal platelets L ratio 1.9–2.1); frontal margin medially with large anterolaterally pointed apodemes (
Fig. 24D
); Cxgl-4 located far anteriorly, near tips of Cx-I; gnathosomal bay moderately deep, V-shaped, three pairs of knob-like protrusions at the lateral margins of gnathosomal bay; suture line of Cx-IV distinct, originating from lateral edge of genital field; posterior line of primary sclerotization close to posterior margin of genital field; excretory pore and Vgl-2 well separated from the line of primary sclerotization, Vgl–2 posterior to excretory pore; gnathosoma with long dorsal apodemes, rostrum truncated (
Fig. 23D
); distal margin of P-3 and P-4 medially with several pointed extensions; P- 4 with two ventral setae, one very long and away from distal edge (
Figs. 23C
,
24C
). Male: medial margin of Cx-II/ III relatively short; genital field subrectangular; ejaculatory complex (
Figs. 23E
,
44D
) with large proximal chamber,
carina anterior
short. Female: genital field pentagonal, anteriorly enlarged, laterally straight, tapering posteriorly.
FIGURE 23A–E.
Monatractides
cf.
ventriosus
(K. Viets, 1916)
, male, Laboun River: A = dorsal shield; B = idiosoma, ventral view; C = palp, lateral view (P-1 lacking); D = gnathosoma; E = ejaculatory complex. Scale bars = 100 Μm.
FIGURE 24A–D.
Monatractides
cf.
ventriosus
(K. Viets, 1916)
, female, Agumatsa River: A = dorsal shield; B = idiosoma, ventral view; C = palp, medial view; D = frontal margin of idiosoma, dorsal view. Scale bars = 100 Μm.
Remarks
. Since the original description of
Monatractides ventriosus
based on a single female from
Cameroon
(
K. Viets, 1916
), water mites from different regions of Africa have been assigned to this species. As stated by
Cook (1966)
,
Goldschmidt & Smit (2009)
and Smit
et al
. (2010), the variability of populations from different regions of the whole distribution area needs to be examined to clarify the taxonomy. The first step in that should be to collect additional material as well as finding a male from the
locus typicus
of
M. ventriosus
.
FIGURE 25A–I.
Photographs of dorsal shield.
A
Monatractides acutiscutatus
(K. Viets, 1914)
, female, unnamed creek upstream Sagyimase.
B–C
M. convexiscutata
(K. Viets, 1958)
, stream Asukuma: B = male, C = female.
D–E
M. koenikei
(K. Viets, 1916)
: D = male from Nubui River, E = female from Akaa Falls.
F–G
M. stigeophora
(Cook, 1966)
, female: F = specimen from Supon stream, G = juvenile specimen from stream upstream Sagyimase.
H–I
M.
cf.
ventriosus
(K. Viets, 1916)
: H = male from Laboun River, I = female from Agumatsa River.
FIGURE 26A–I.
Photographs of ventral shield.
A
Monatractides acutiscutatus
(K. Viets, 1914)
, female, unnamed creek upstream Sagyimase.
B–C
M. convexiscutata
(K. Viets, 1958)
, stream Asukuma: B = male, C = female.
D–E
M. koenikei
(K. Viets, 1916)
: D = male from Nubui River, E = female from Akaa Falls.
F–G
M. stigeophora
(Cook, 1966)
, female: F = specimen from Supon stream, G = juvenile specimen from stream upstream Sagyimase.
H–I
M.
cf.
ventriosus
(K. Viets, 1916)
: H = male from Laboun River, I = female from Agumatsa River.
TABLE 3.
Measurements of
Monatractides
cf.
ventriosus
(K. Viets, 1916)
from Ghana.
Laboun River, ♂ Laboun falls, ♂ Laboun falls, ♀ Agumatsa River, ♀ In comparison with specimens from
Liberia
described by
Cook (1966)
, specimens in our study are notably smaller, but do not differ in proportions and general idiosoma and palp morphology. On the other hand, comparison with figures from the original description of
K. Viets (1916)
suggests that specimens in our study cannot be conspecific with
M. ventriosus
. The ventral setae on P-
4 in
the
type
specimen are short, not reaching the tip of P-5. In our specimens, and in specimens from
Liberia
(see
Cook 1966
), one of P-4 ventral setae is characteristically very long and away from the distal edge. As already observed by
Cook (1966)
the palps in specimens from
Liberia
are more like those illustrated by
Lundblad (1952)
for
M. ventriosus
from
Kenya
. However, the specimens from our study differ from specimens from
Kenya
assigned by
Lundblad (1952)
to
M. ventriosus
, in the shape of the ejaculatory complex with a large proximal chamber (vs. small proximal chamber in specimens from
Kenya
, see
Lundblad 1952
: fig. 39E,
typus
of
Torrenticola elgonensis
[syn. to
Monatractides elgonensis
]).
Lundblad (1952)
synonymized
M. lemnia
Lundblad, 1927
and
M. elgonensis
Lundblad, 1941
with
M. ventriosus
. It is worth mentioning that in 1941 Lundblad described a female from
Kenya
as subspecies
stenostomoides
, characterized by shorter ventral seta on P-4, not reaching the tip of P-5 (see
Lundblad 1952
, Fig, 40D).
K.O. Viets (1965)
reported a male of
M. ventriosus stenostomoides
from Transvaal,
South Africa
.
Idiosoma L 578 |
552 |
681 |
694 |
Idiosoma W 458 |
441 |
572 |
575 |
Idiosoma L/W ratio 1.26 |
1.25 |
1.19 |
1.2 |
Ds L 498 |
478 |
594 |
606 |
Ds W 396 |
388 |
487 |
480 |
Ds L/W ratio 1.26 |
1.23 |
1.22 |
1.26 |
Dp L 453 |
426 |
547 |
557 |
Sh plate L 191–194 |
180–183 |
208–213 |
216 |
Sh plate W 70–71 |
66–69 |
78 |
77–78 |
Sh plate L/W 2.7–2.8 |
2.6–2.8 |
2.7 |
2.8 |
F plate L 97–103 |
97 |
103–106 |
105 |
F plate W 70 |
69 |
72–73 |
75–77 |
F plate L/W ratio 1.4–1.5 |
1.4 |
1.4–1.5 |
1.4 |
Sh pl L/f pl L ratio 1.9–2.0 |
1.9 |
2.0 |
2.06 |
Gnathosomal bay L 100 |
103 |
115 |
120 |
Cx-I L 238 |
214 |
250 |
256 |
Cx-I mL 138 |
111 |
134 |
136 |
Cx-II+III mL 73 |
68 |
63 |
72 |
Cx-1 L/Cx-II+III mL 3.3 |
3.2 |
4.0 |
3.6 |
Cx-I mL/Cx-II+III mL ratio 1.9 |
1.6 |
2.1 |
1.9 |
Genital field L 119 |
116 |
148 |
148 |
Genital field W 100 |
103 |
147 |
138 |
Gf L/W ratio 1.19 |
1.12 |
1.01 |
1.08 |
Dist gf—expo 116 |
113 |
141 |
153 |
Dist gf—cauda 144 |
153 |
219 |
219 |
Ec L 166 |
162 |
- |
- |
Gnathosoma vL 125 |
115 |
142 |
132 |
Chelicera L 149 |
157 |
177 |
175 |
Palp, total L 174–175 |
166 |
193–195 |
195–196 |
P-1 dL/H 18–19/21 |
20/20 |
21–22/22 |
21–22/22 |
P-2 dL/H 48/37 |
44/33 |
55/35 |
51/37 |
P-3 dL/H 34/28 |
31/25 |
40/30 |
37/29 |
P-4 dL/H 46/18–19 |
46/17 |
48–49/21 |
54/20 |
P-5 dL/H 28/11 |
25/11 |
29/14 |
32/12 |
P-1 dL/H ratio 0.89 |
1.0 |
0.97 |
0.98 |
P-2 dL/H ratio 1.29 |
1.33 |
1.58 |
1.38 |
P-3 dL/H ratio 1.26 |
1.21 |
1.33 |
1.27 |
P-4 dL/H ratio 2.5 |
2.7 |
2.3 |
2.7 |
P-5 dL/H ratio 2.6 |
1.7 |
2.1 |
2.7 |
dL P-2/P-4 ratio 1.03 |
0.96 |
1.14 |
0.94 |
I-L-4 L 79 |
80 |
95 |
94 |
I-L-5 L 77 |
75 |
88 |
89 |
I-L-6 L 82 |
77 |
90 |
89 |
I-L-6 H 36 |
33 |
34 |
31 |
I-L-6 L/H ratio 2.3 |
2.3 |
2.6 |
2.9 |
It is likely the species from our material from
Ghana
and from
Liberia
(
Cook 1966
) represents the same, undescribed species. However, no illustration had been given of the ejaculatory complex by
Cook (1966)
for specimens from
Liberia
. Introducing a new species, in our opinion, will create more confusion given the present state of knowledge of this species.