Protolimnesia longa Besch 1963
Creators: name: Pešić, Vladimir
name: Smit, Harry
name: Datry, Thibault
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Limnesiidae
Protolimnesia
Protolimnesia longa

description: Protolimnesia longa Besch, 1963
(Fig. 1A–G)
Material examined. Bolivia, Cochabamba Department, unnamed ephemeral stream in the Sacaba area, 17°30'10.43"S,
66°1'51.66"W, alt. 3286 m asl., 03.viii.2015, Karaman-Chappuis digging, leg. Datry, one male, one female, dissected and
slide mounted in Hoyer's fluid.
Morphology. General features. Dorsum with one large postero-medial plate and two pairs of small anterior platelets
(Fig. 1A); integument reticulate areolate; lateral eyes small and oval, eye pigment reduced; coxae in four separated
groups; Cx-I approaching medially, but separated; glandulae limnesiae centro-medially of anterior margin of Cx-III, not
in the membranous area; Cx-IV with subcutaneous projection at posterior part of medial margin; genital flaps bearing
three pairs of irregular oval, medium-large acetabula; excretory pore smooth; I–III-leg claws bearing strong claws with
distinct clawlets; IV-L-6 bearing strong claws with distinct clawlets and a sub-terminal seta (Fig. 1C). Male. Dorsum with rectangular postero-medial plate (Fig. 1A). Coxal field (Fig. 1B): Cxgl– 4 in antero-medial
region of Cx-III; number of coxal setae: Cx-I, 6; Cx-II, 5; Cx-III, 3–4; Cx-IV, 2; caudal margin of genital field not
reaching posterior margin of Cx-IV, genital field apple-shaped, distance between Ac-1 and Ac-2 slightly larger than distance between Ac-2 and Ac-3, Ac-2 smaller than Ac-1 and Ac-3, Ac-1 and Ac-3 elongated-oval, with a weak central indentation; Ac-2 a bit smaller than Ac-1 and Ac-3, genital plates with two setae anterior of Ac-1, further two setae between Ac-1 and Ac-2, two setae between Ac-2 and Ac-3, one seta in postero-medial corner, as well as some setae lateral to Ac-1, -2 and -3; pre- and post-genital sclerites irregularly elongated-oval (Fig. 1B). Palp: P-2 with a heavy, pegshaped ventral seta; P-4 ventral margin with one long seta associated with a tubercle, and two further small setae, each accompanied by a tubercle (Figs. 1C–D). Ejaculatory complex with long distal arms and clearly developed proximal arms (Figs. 1F–G).
Female. Arrangement of dorsal plates and glandularia as in male, but postero-medial plate almost circular in shape (Fig. 2C). Integument structure, shape of coxal field, setae of legs, shape and setae of gnathosoma and palps (Fig. 2B) as in male; clear sexual dimorphism in the shape of the genital field. Genital flaps longer, outline appears almost rectangular (Fig. 2A); genital field caudally reaching beyond Cx-IV, pre-genital sclerite medium-large; distance between Ac-1 and Ac-2 larger than between Ac-2 and Ac-3; two setae anterior of Ac-1, a further four to six setae between Ac-1 and Ac-2, as well as two setae between Ac-2 and Ac-3, one lateral to Ac-2, and one seta in postero-medial corner of genital flaps.
Measurements. Male. Idiosoma L/W 730/500; postero-dorsal plate L/W 109/95, ratio 1.15; coxal field L/W 383/ 434, ratio 0.88; genital field L/W 131/141, ratio 0.93, pre-genital sclerite W 19; Ac-1–3 L: 42, 31–33, 35–41; ejaculatory complex L 168. Palp: total L 335; L/H, L/H ratio: P-1, 30/37, 0.82; P-2, 94/60, 1.57; P-3, 60/48, 1.26; P-4, 109/32, 3.5; P-5, 42 /17, 2.4; gnathosoma vL 134; chelicera total L 209, H 50, L/H ratio 4.2, claw L 62, basal segment 149, L basal segment/claw ratio 2.4. Legs: dL of I-L: 37, 75, 88, 100, 122, 141; I-L-6 H 34. L/H I-L-6 ratio 4.2; dL of IV-L: 72, 85, 123, 172, 172, 209; IV-L-6 subterminal seta L 51.
Female. Idiosoma L/W 1000/700; postero-dorsal plate L/W 100/106, ratio 0.94; coxal field L/W 390/560, ratio 0.7; genital flaps L/W 153/50, ratio 3.1, pre-genital sclerite W 69; Ac-1–3 L: 38–47, 36, 35–38; egg maximum diameter 231. Palp: total L 340; L/H, L/H ratio: P-1, 29/36, 0.81; P-2, 93/55, 1.68; P-3, 62/46, 1.35; P-4, 111/32, 3.5; P-5, 45/19, 2.4; gnathosoma vL 131; chelicera total L 219. Legs: dL of I-L: 57, 69, 92, 103, 125, 142; I-L-6 H 33. L/H I-L-6 ratio 4.3; dL of IV-L: 111, 89, 119, 171, 217, 194; IV-L-6 subterminal seta L 45.
Remarks. The specimens from Bolivia agree well in general morphology with Protolimnesia longa Besch, 1963. Protolimnesia longa can easily be distinguished from other members of the genus by a reticulate pattern of the integument, two pairs of medial and anterior dorsal plates and a small genital field. The only difference towards the type specimen from Argentina is found in the almost rectangular shape of the dorsal postero-medial plate in the male from our study compared with the almost circular postero-medial plate in the original description (see Besch 1963, fig. 2).
Habitat. Protolimnesia longa seems to be a characteristic dweller of interstitial waters of ephemeral streams. The sampling site in Bolivia is an ephemeral stream located in the Sacaba area (Cochabamba, Bolivia) (Fig. 3A–B). This stream flows about 3–5 months during the year, but species of several aquatic groups such as beetles (Psephenidae, Dytiscidae), dipterans (Stratiomyidae, Sciomyzidae, Ceratopogonidae, Dolichopodidae, Chironomidae), caddisflies (Hydroptilidae) and mayflies (Caenidae) are found to be able to survive in the dry sediments (Datry, unpublished data).
Distribution. Argentina (Besch 1963), Bolivia (this study).
description: Published as part of Pešić, Vladimir, Smit, Harry & Datry, Thibault, 2016, A redescription of Protolimnesia longa Besch, 1963 from Bolivia, with the first description of the female (Acari: Hydrachnidia: Limnesiidae), pp. 81-84 in Zootaxa 4121 (1) on pages 81-84, DOI: 10.11646/zootaxa.4121.1.7, http://zenodo.org/record/256041