Diplothyrus, Lehtinen, 1999

Bernardi, L. Ferreira de Oliveira, Azara, L. Neves de & Ferreira, R. Lopes, 2011, Description Of The Female Of Diplothyrus Schubarti Lehtinen, 1999 (Holothyrida: Neothyridae) And New Species Occurrences In Brazil, Acarologia 51 (3), pp. 311-319 : 318

Diplothyrus schubarti

Idiosoma — The female idiosoma well sclerotized, of light brown coloration, its length 1720 – 1760 µm and width 1160 – 1200 µm ( Figure 2A and 2B ).

Dorsal view — Strongly arched, hypertrichous, the entire dorsum being covered by concavities. On the lateral area of the dorsal disk, it is possible to see the stigma, a small opening located above the fourth coxa. The Thon’s organ is visible externally, however it is short (235 – 240 µm), extending to the anterior region and located above the third and fourth coxae ( Figure 3 ).

Ventral view — Presents a homogeneous distribution of setae on the ventral shield. Sternal lyrifissures (if present) not observed. The ventral shield is separate from the dorsal shield by a continuous fissure. The anal opening of the female is composed by two valves, with length of 130 – 135 µm and width 170 – 172 µm.

The genital area of the female has a length of 525 – 530 µm and width of 500 – 505 µm, with rounded shape. Similar to that observed for the remainder of the body, the female genital opening presents round concavities and hypertrichy. The central plate (postgenital shield) is notably larger than the other plates located on the sides (laterogenital shield) and on the anterior area (pregenital shield) ( Figure 4 ).

Legs — Length of the legs I-IV (female): 1875 – 2070 µm, 1545 – 1705 µm, 1635 – 1835 µm and 2005 – 2220 µm, respectively.

Subcapitulum — Length of 350 – 400 µm. Possesses 3 pairs of setae on the central region, a pair of setae on the central portion of the anterior area, a pair of setae located below the corniculi and three pairs of setae on the region of the posterior lateral margin. Gnathotectum (Figure 5C).

Palpus — Total Length 675 – 690 µm.

Chelicerae — Length 385 – 395 µm. The fixed digit is covered by two robust teeth, one on the anterior portion and the other on the central area. There is a row of small denticles between the teeth a row of small denticles is observed. Posterior to the central digit fine serrated edge is observed that is on the internal part of the fixed digit. The movable digit also possesses two robust teeth, one on the anterior portion and the other on the central area (Figure 5A and 5B).

The morphological measurements of males do not considerably differ from those of the females, with an exception for the genital plates ( Table 1).

Figures

FIGURE 2: Diplothyrus schubarti. Overview of the ventral idiosoma. A – male, B – female.

FIGURE 3: Diplothyrus schubarti. Detail of tegument, opening of Thon’s organ of female.

FIGURE 4: Diplothyrus schubarti. Genital opening of female. PRG: pregenital shield, LAG: laterogetinal shield, POG: posgenital shield.