Monatractides ventriosus K. Viets 1916
Creators: name: Pešić, Vladimir
name: Smit, Harry
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Torrenticolidae
Monatractides
Monatractides ventriosus

description: 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.
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.
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.
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.
description: Published as part of Pešić, Vladimir & Smit, Harry, 2014, Torrenticolid water mites (Acari: Hydrachnidia: Torrenticolidae) from Ghana, pp. 1-80 in Zootaxa 3820 (1) on pages 36-42, DOI: 10.11646/zootaxa.3820.1.1, http://zenodo.org/record/286303