Larval morphology of Hydryphantes clypeatus Thor, 1899, H. dispar Schaub, 1888 and H. planus Thon, 1899 (Acari, Hydrachnidia: Hydryphantidae)AuthorTuzovskij, Petr V.textZootaxa201438692131142journal article10.11646/zootaxa.3869.2.21b120e50-8746-4498-a243-8d4649cdb8db1175-5326228749407C7804-ABAB-4419-A4E3-478856A3A57BHydryphantes clypeatus
(Thor, 1899)
(
Figs 1–16
)
Material examined
. Larvae (n = 26) were reared from four females collected in a sedge bog near village Postyltsevo, Nekouz District, Yaroslavl Province: two females
25 May 2000
, one female
1 June 2002
and one female
10 June 2004
. The duration of the embryonic period was 12–15 days.
Diagnosis. Larva.
Distance between bases of trichobothria
Oi
larger than their length; all dorsal hysterosomal setae subequal; excretory pore plate wider than long; urstigma wider than long; posterior margin of coxal plate II convex; P-5 with long solenidion; I–II-Leg-4 solenidia 2.0–2.5 times longer than eupathidia; I–II-Leg-5 with unequal solenidia; I-Leg-6
de
shorter than
ds
.
Description
. Colour red. Anterior pair of platelets small, more or less triangular, posterior plate relatively large, anteriorly narrow, posteriorly widening; median eye weakly developed and situated between setae
Vi
(
Fig. 1
). Both pairs of trichobothria thin,
Fp
very long,
Oi
short. Distance between bases of trichobothria
Oi
larger than their length. Simple proterosomal setae (
Fch
and
Vi
) thick, but
Fch
slightly shorter than
Vi
. Other dorsal setae (
Oe, Hi, He, Sci, Sce, Li
and
Le
) thick and approximately equal in length. lateral eyes with anterior lenses large and circular, posterior lenses elongate.
Coxal plates II triangular, coxal plates I and III more or less trapezoidal and rounded medially (
Fig. 2
); all coxal setae relatively short and subequal. Urstigma rather large, wider than long. Setae
Si
slightly longer than other ventral idiosomal setae. Setae
Se, Ci, Pi
and
Pe
subequal and slightly longer and thicker than both pairs of anal setae. Excretory pore plate small and usually wider than long (Figs 3, 5). Bases of setae
Ae
near middle or in posterior portion of excretory pore plate.
Chelicera (Fig. 6) with large basal segment and small stylet. Basal segment of chelicera with rather wide strips.Pedipalps stout (Fig. 7): P-1 short, without seta; P-2 large with convex dorsal margin and a single dorsal seta in proximal part; P-3 with two subequal setae (proximal and distal); P-4 with three thin subequal setae and large dorsodistal claw; P-5 small conical, with a single moderately long solenidion and seven setae, five long and thick, two short and thin.
Legs 6-segmented. Shape and arrangement of specialized setae on terminal leg segments as shown in Figs 8–
10
. I–II-Leg-4 solenidia 2.0–2.5 times longer than eupathidia; I-Leg-5 and II-Leg-5 with two proximal unequal solenidia; I-Leg-6
de
shorter than
ds
; II-Leg-6 solenidion in proximal, eupathidium in submedial position. Claws of legs III slightly larger than claws of legs I and II. Lateral claws shorter and thinner than the strong empodial claw (Fig.11).
Measurements, n=10. Dorsal plate L 45–48, W 41–44; setae
Fch
L 21–23, setae
Fp
L 62–69, setae
Vi
L 28–32, setae
Oi
L
8
–10, setae
Oe, Hi, He, Sci, Sce, Li, Le
and
Si
L 26–28; setae
Se
,
Ci, Pi
and
Pe
L 16–18, setae
Ai
and
Ae
L 13–14; distance between setae
Vi–
Vi
31–35, distance between setae
Oi-Oi
17–20; excretory pore plate L 6–9, W 10–12; basal segments of chelicera L 68–73, cheliceral stylet L 13–14; strips on basal segment of chelicera
W 0.5
–0.7; pedipalpal segments (P-1–5) L: 6–7, 27–29, 22–25, 15–19, 10–11; leg segments L: I-Leg-1–6: 23–27, 18–24, 15–19, 25–28, 32–37, 62–65; II-Leg-1–6: 22–25, 17–19, 11–13, 16–19, 30–32, 46–50; III-Leg-1–6: 22–25, 17–23, 12–15, 20–23, 33–37, 45–48.
Female.
Integument soft with rather long rounded papillae (
Fig. 12
). Frontal plate (
Fig. 13
) compact and nearly quadrate, anterior margin slightly convex or obtuse-angled, lateral margins concave, posterior margin straight, lateral and posterior extensions short. Median eye small and situated slightly posterior to anterior setae.
Capitulum (
Fig.14
) with equally S-shaped ventral margin and rather long rostrum (base of capitulum/rostrum L ratio 4.4–5.1). Chelicera (
Fig.15
) slender, basal segment with obtuse-angled hump near middle, cheliceral stylet moderate in length.
Pedipalp slender (
Fig. 16
): P-1 with 3–4 dorsodistal setae; P-2 with 10–13 setae; P-3 usually with two long dorsodistal setae (occasionally an additional short one); P-4 slender with three thin distal setae and a short, thick dorsodistal spine.
Measurements, n=5. Idiosoma L 1100–1400; dorsal plate L 360–400, W 360–390; genital flap L 235–250, W 110–125; genital acetabula (ac.1–ac.3) L 35–42, 25–30, 55–63; capitulum L 275– 290, rostrum L 55–63, chelicera L 360–375, cheliceral stylet L 120–125; pedipalpal segments (P-1–5) L: 62–75, 110–120, 60–90, 185–200, 25–30; leg segments L: I-Leg-1–6: 75–90, 110–135, 135–140, 210–220, 235–250, 250–265; II-Leg-1–6: 100–105, 125–140, 160–175, 275–290, 325–340, 325–350; III-Leg-1–6: 95–105, 125–140, 170–180, 385–300, 325–340, 330–340; IV-Leg-1–6: 180–190, 185–200, 250–265, 400–415, 285–400, 335–350.Remarks.Lundblad (1962)
considered
H. clypeatus
, as well as the species and subspecies
H. bayeri
Pisarovic, 1896
,
H. bayeri nonundulatus
Viets, 1919
,
H. affinis
Sokolow, 1931
and
H. ruber tuxeni
Motas, 1961
, as junior synonyms of
H. planus
. However, clear differences can be found both in the larvae and females of
H. clypeatus
.
The larva is similar to the larva of
H. planus
(see description of this species). However, the latter differs from
H. clypeatus
in: (1) the posterior margin of the coxal plate II straight (
Fig. 33
), not convex; (2) the excretory pore plate is longer than wide (
Fig. 34
–55); (3) P-5 with short solenidion (
Fig. 37
); (4) I-Leg-4 solenidion slightly shorter than eupathidium (
Fig. 38
), I-Leg-6
de
as long as
ds.