Eylais extendens ( Müller, 1776 )

Hajizadeh, Jalil & Hosseini, Reza, 2022, Redescription of the water mite Eylais extendens (Müller) (Acari, Eylaidae) larva based on material collected from Iran, Persian Journal of Acarology 11 (1), pp. 51-58 : 52-55

publication ID	https://doi.org/ 10.22073/pja.v11i1.71579
persistent identifier	https://treatment.plazi.org/id/03AA87C0-B736-9656-1C4F-0566E9059A11
treatment provided by	Felipe
scientific name	Eylais extendens ( Müller, 1776 )
status

Treatment

Eylais extendens ( Müller, 1776)

Syn.: Hydrachna extendens Müller, 1776: 190 .

Eylais undulosa Koenike, 1897: 283 .

Eylais extendens monofissa Szalay, 1934: 277 .

Redescription (n = 5)

Dorsum – Body elongate oval, color in life red, body length 176 (175–178), width 124 (118– 135) ( Fig. 2A View Figure 2 ). Dorsal shield oval, length 147 (143–152), width 62 (58–68). Anterior margin triangular, posterior margin rounded, weakly narrowed, with seven pairs of setae, first pair is longer than the other pairs and six pairs of large pores; pores surrounded by radially arranged short furrows; longitudinal lateral furrows not developed, distinct only in the intervals between the anterior margin and first pairs of pores; third pair of pores connecting by a transverse furrow ( Figs. 1A View Figure 1 , 2A View Figure 2 ). The ocular plates lie on each side of the dorsal plate with two separate lens-like structures, length 33 (28– 38) ( Fig. 2A View Figure 2 ). Two triangular-shaped lateral plates lie posterior to the ocular plates, each lateral plate bears two side-by-side arranged setae, length 29 (28–30) ( Fig. 2A View Figure 2 ). Measurements of body parts are given in Table 1.

Gnathosoma; D. Palp; E. velum. Scale bar: 68 μm for A and B; 28 μm for C; 33 μm for D; 30 μm for E.

Venter ( Fig. 2B View Figure 2 ) – Coxal plates I and II are fused together, each with 2 setae, coxal plate III separate contains 2 setae; anal shield long, narrowed at both ends, lying between the posterolateral plates, two small pores situated in front of the excretory pore; posterior lateral plates lie posterior to coxae III, tapering to a point beside the excretory plate, each with 4 setae ( Figs. 1B View Figure 1 , 2B View Figure 2 ).

Gnathosoma ( Fig. 2C View Figure 2 ) – Mouthparts include the chelicerae, palps and rostrum that supported by basis capitulum. The stylophore consist of fused basal segments of the chelicerae that forms the dorsal cover for the mouthparts. Stylophore oviform, length 36 (33–42), anterior margin rounded, posterior margin weakly narrowed ( Fig. 1E View Figure 1 ). The velum, which holds the mouthparts of the larva to the integument is on the ventral face of the rostrum. Velum with two rows of eight large papillae, proto- and tritorostral setae visible ( Figs. 1C View Figure 1 , 2E View Figure 2 ). Chelicera triangular in outline, pointed at tip, tip is weakly bent, its length exceeds than basal width. Pedipalp large, five segmented, trochanter short, discoid; femur and genu moderately developed, genu with a narrow medial crest, tibia with large furcate setae, with a developed wing-shaped branch, tibial claw length 23 (20–24), tarsus bilobed, with two normal setae and one solenidion ( Figs. 1D View Figure 1 , 2D View Figure 2 ).

Legs ( Fig. 3 View Figure 3 ) – The number of leg setae from coxa to tarsus is 2-1-5-4-9-18; epimera I and II partly fused ( Figs. 1B View Figure 1 , 2B View Figure 2 ); legs terminate in two sickle-shaped claws ( Fig. 3D View Figure 3 ); all legs have a trichobothrium on the dorsal surface of the telofemur ( Fig. 3B View Figure 3 ); solenidion on tarsus II 22 (18–23) long ( Fig. 3C View Figure 3 ); length of legs I-III respectively: I, 153; II, 156; III, 168; length of leg segments given in Table 1.

Material examined

Twenty larvae of Eylais extendens were separated from abdominal tergites of the water beetles of families Noteridae and Dytiscidae . Two larvae were separated from leg (femur) of water beetles of family Heteroceridae ( Fig. 4 View Figure 4 ).

Kingdom	Animalia
Phylum	Arthropoda
Class	Arachnida
Order	Trombidiformes
Family	Eylaidae
Genus	Eylais

Kingdom	Animalia
Phylum	Arthropoda
Class	Arachnida
Order	Trombidiformes
Family	Hydrachnidae
Genus	Hydrachna