Neumania (Neumania) imitata Koenike, 1908

Tuzovskij, Petr V., 2012, Larval morphology of Unionicola figuralis (Koch, 1836), Neumania imitata Koenike, 1908, and N. spinipes (Müller, 1776) (Acari: Hydrachnidia: Unionicolidae), Zootaxa 3506, pp. 43-56 : 47-52

publication ID	https://doi.org/ 10.5281/zenodo.282494
DOI	https://doi.org/10.5281/zenodo.6166624
persistent identifier	https://treatment.plazi.org/id/03C82744-C417-FFC8-FF64-FC05D81E9229
treatment provided by	Plazi
scientific name	Neumania (Neumania) imitata Koenike, 1908
status

Treatment

( Figs 12–23 View FIGURES 12 – 13 View FIGURES 14 – 19 View FIGURES 20 – 23 )

Material examined. Larvae (n = 37) were reared from four females collected in Il’d stream near village Mar’ino, Nekouz District, Yaroslavl Province: two females 19 August 2004, one female 22 July 2005, and one female 15 July 2006. The duration of the embryonic period was 12–14 days at room temperature.

Diagnosis. Dorsal plate elongated (L/W ratio 1.7–2.1), tmas well developed; excretory pore plate broad and straight anteriorly, narrow posteriorly, excretory pore located near middle of the plate; chelicerae longer than wide; P-5 with three long and four short simple setae; II—Leg-4 with three greatly thickened setae; acanthoid seta on tarsi I to III reduced and represented in form of alveolus.

Description. Idiosoma flat, dorsal plate in unengorged larvae covering almost the whole dorsum ( Fig. 12 View FIGURES 12 – 13 ), with slightly convex lateral margins, its anterior margin straight, posterior margin rounded, with slightly elongate and punctuate scale-like patterns. All four pairs of setae on the dorsal plate thin and approximately equal in length. Setae Oe, Hi, He, Sci, Sce, Li, Le and Si situated in soft membrane: Oe longest, Li and Si shortest; Hi, He, Sci, Sce and Le moderately in length and subequal.

Coxal plates moderately large and elongate, plates II–III with a posteromedial muscle attachment scar on each side and rounded posterior margins ( Fig. 13 View FIGURES 12 – 13 ). Setae C1 relatively short and extending beyond bases of C4; the latter setae little longer than C2 and C3, and extending to posterior margin of coxal plates II–III. Setae Ci very long, well thickened, located on small tubercles. Setae Se and Pe short, thin and much shorter than Pi. Excretory pore plate oval or pentagonal, longer than wide (L/W ratio 1.28–1.45), narrow anteriorly ( Figs. 14–16 View FIGURES 14 – 19 ). Setae Ai relatively short, thin located anteriorly close to each other, and not reaching to posterior margin of excretory pore plate. Setae Ae longer and thicker than Ai, located laterally nearly in middle of plate, and extending well beyond posterior margin of excretory pore plate; excretory pore placed near the middle of the plate; distance between setae Ae–Ae almost twice time longer than distance between Ai–Ai. Setae Pi located very close anterior to excretory pore plate.

Chelicerae ( Fig. 17 View FIGURES 14 – 19 ) short and very heavy, longer than wide; basal segments expanded proximally and tapering distally; cheliceral stylets small and hidden in the anterior region of chelicerae, crescent-shaped ( Fig. 18 View FIGURES 14 – 19 ).

Pedipalps very short and stocky ( Fig. 19 View FIGURES 14 – 19 ); P-1 short; P-2 large with slightly convex dorsal margin, dorsal seta usually absent or its location visible as alveole; P-3 with very long, thick lateroproximal seta and relatively short, fine dorsodistal one; P-4 with two unequal setae (long and short) and massive dorsodistal claw; P-5 small, with single solenidion, three long and four short simple setae.

Shape and arrangement of setae on legs segments as shown in Figs 20–22 View FIGURES 20 – 23 . Total number of leg setae, excluding eupathidia, as follows (specialized setae indicated in parentheses): I—Leg-1–5: 1, 7, 5 (s), 10 (2s), 10 (s, ac); II—Leg-1–5: 1, 7, 5 (s), 11 (2s), 10 (s, ac); III—Leg-1–5: 1, 6, 5 (s), 10 (s), 9 (ac). Acanthoid setae usually reduced and represented in form of alveoli only. Number of thickened setae from trochanter to tarsus: I—Leg: 0, 2, 1, 2, 0; II—Leg: 0, 1, 1, 3, 0; III—Leg: 0, 2, 3, 4, 0. I—Leg-1 with relatively short seta, II—Leg-1 and III—Leg-1 each with long seta. Solenidion on I—Leg-3 and II—Leg-3 much longer than solenidion on III—Leg-3. Both solenidia on I—Leg-4 subequal and shorter than solenidion on I—Leg-3 but longer than solenidion on I—Leg-5. Solenidion on II—Leg-3 and II—Leg-5 and both solenidia on II—Leg-4 approximately equal in length. Acanthoid seta (= Ta2 after Prasad & Cook 1972) on tarsi I to III reduced and represented in form of alveolus. Lateral claws and empodial claw nearly equal in length, but lateral claws less heavy than empodial claw ( Fig. 23 View FIGURES 20 – 23 ).

Measurements, n=10. L of dorsal plate 205–215, W 100–115; L of setae Fch, Fp, Vi, Oi 25–32; Oe 85–95; L of setae Hi, He, Sci, Sce 40–50, L of setae Li and Si 9–12; L of setae Le 40–45; L of setae Se 18–23, L of setae Ci 115–130, L of setae Pi 25–29, L of setae Pe 16–22, L of setae Ai 12–16, L of setae Ae 17–20; L of setae C1 55–65, L of setae C2 65–70, L of setae C3 67–75, L of setae C4 70–77; L of medial edge of coxa I 85 –93, L of medial edges of coxae II–III 105–125; L of excretory pore plate 22–29, W 16–23; L of basal segments of chelicerae 50–60, W 38–42; L of cheliceral stylet 21–24; L of pedipalpal segments (P–1–5): 3–4, 25–29, 14–16, 5–6, 3–4; L of legs segments: I—Leg-1–5: 22–26, 25–32, 25–30, 38–42, 48–52; II—Leg-1–5: 22–26, 25–32, 28–32, 40–44, 57–64; III—Leg-1–5: 28–32, 25–30, 32–36, 40–45, 57–65.

Remarks. The combination of the following characters separate the larva of N. spinipes from all others known species of the subgenus Neumania : the excretory pore plate broad and straight anteriorly, the excretory pore located near the middle of the plate; the chelicerae are longer than wide; II—Leg-4 with three greatly thickened setae; the acanthoid seta on the tarsi I to III reduced and represented in form of alveolus.

Distribution. Sweden, the Netherlands, Germany, France, Italy, Montenegro ( Viets 1956, Lundblad 1968, Pesiċ et al. 2007). This species is found in Russia for the first time.

Neumania (Neumania) spinipes (Müller, 1776) ( Figs 24–34 View FIGURES 24 – 25 View FIGURES 26 – 31 View FIGURES 32 – 34 )

Material examined. Larvae (n = 10) were reared from single female collected in forest pond near settlement Borok, Nekouz District, Yaroslavl Province, 27 July 2000. The duration of the embryonic period was 11 days at room temperature.

Diagnosis. Dorsal plate elongated (L/W ratio 1.6–1.7), tmas rudimentary; excretory pore plate elongate with minute anterior median projection, excretory pore located in anterior half of excretory pore plate; basal segments of chelicerae longer than wide; P-5 with two relatively long and five short simple setae; II—Leg-4 with two greatly thickened setae; tibia of legs II and III has three long solenidia.

Description. Idiosoma flat, dorsal plate in unengorged larvae covering almost the whole dorsum ( Fig. 24 View FIGURES 24 – 25 ), with slightly convex lateral margins, its anterior margin straight or slightly convex, posterior margin rounded, with short and punctuate scale-like patterns; setae Vi longer than Fch, Fp and Oi which thin and approximately equal in length. Setae Oe, Hi, He, Sci, Sce, Li, Li and Si situated in soft membrane: Oe longest; Li and Si shortest; Hi, He, Sci, Sce and Le moderately in length.

Coxal plates moderately large and elongate, plate II–III with a very short posteromedial muscle attachment scar on each side and rounded posterior margins ( Fig. 25 View FIGURES 24 – 25 ). Setae C1 relatively short and extending beyond bases of C4; the latter setae a little longer than C2 and C3, but not reaching to posterior margin of coxal plates II–III. Setae Ci very long, well thickened, located on small tubercles. Setae Se, Pe and Pi moderately in length. Excretory pore plate elongate (L/W ratio 2.1–2.7) with minute anterior median projection ( Figs 26 –27 View FIGURES 26 – 31 ); setae Ai relatively short, thin located anteriorly close to each other, and not reaching to posterior margin of excretory pore plate; setae Ae longer and thicker than Ai, located laterally nearly in middle of plate, and extending well beyond posterior margin of excretory pore plate; excretory pore located in anterior half of plate; distance between setae Ae–Ae almost twice time longer than distance between Ai–Ai.

Gnathosomal base ( Fig. 28 View FIGURES 26 – 31 ) with wide base and narrow rostrum. Basal part of gnathosomal base longer than rostrum, anterior hypostomal setae longer than posterior ones. Basal segment of chelicerae fused to each other medially, longer than wide, expanded proximally and tapering distally ( Fig. 29 View FIGURES 26 – 31 ); cheliceral stylets small and hidden in the anterior region of chelicerae, crescent–shaped.

Pedipalps very short and stocky ( Fig. 30 View FIGURES 26 – 31 ): P–1 short; P–2 large with slightly convex dorsal margin, dorsal seta usually absent or its location visible as alveole; P–3 with very long, thick lateroproximal seta and relatively short dorsodistal one; P–4 with two unequal setae (long and short) and massive dorsodistal claw; P–5 small, with long solenidion, two long and five short simple setae.

Shape and arrangement of setae on legs segments as shown in Figs 31–33 View FIGURES 26 – 31 View FIGURES 32 – 34 . Total number of leg setae, excluding eupathidia, as follows (specialized setae indicated in parentheses): I—Leg-1–5: 1, 7, 5 (s), 11 (2s), 11 (s, ac); II—Leg-1–5: 1, 7, 5 (s), 12 (3s), 11 (s, ac); III—Leg-1–5: 1, 6, 5 (s), 12 (3s), 10 (ac). Number of thickened setae from trochanter to tarsus: I-Leg: 0, 1, 0, 1, 0; II—Leg: 0, 1, 2, 2, 0; III-Leg: 0, 1, 3, 4, 0. I-Leg-1 with relatively short seta, II—Leg-1 and III—Leg-1 each with long seta. Solenidion on I—Leg-3 and II—Leg-3 longer than solenidion on III—Leg-3. Both solenidia on I—Leg-4 subequal and longer than solenidion on I—Leg-3 and on I—Leg-5. Tibia of leg II and III has three long solenidia. Solenidion on II-Leg-3 shorter than solenidia on II—Leg- 4 and solenidion on II—Leg-5. Solenidion on III—Leg-3 much shorter than solenidia on III—Leg-4. Acanthoid seta comparatively long and setose, located distally on tarsus of all legs. Lateral claws and empodial claw nearly equal in length, but lateral claws less heavy than empodial claw ( Fig. 34 View FIGURES 32 – 34 ).

Measurements, n=10. L of dorsal plate 270–295, W 170–175; L of setae Fch 48–53, L of setae Vi 55 –65, L of setae Fp and Oi 40–45; L of setae Oe 115–125; L of setae Hi, He, Sci, Sce 48–55, L of setae Li and Si 18–25; L of setae Le 53–58; L of setae Se 48–55, L of setae Ci 155–165, L of setae Pi 55–65, L of setae Pe 43–48, L of setae Ai 32–35, L of setae Ae 38–42; L of setae C1 85–90, L of setae C2 85–93, L of setae C3 100–105, L of setae C4 110–120; L of medial edge of coxa I 99 –103, L of medial edges of coxae II–III 130–145; L of excretory pore plate 55–60, W 22–26; L of basal segments of chelicerae 67–70, W 54–58; L of cheliceral stylet 22–24; L of pedipalpal segments (P–1–5): 4–6, 35–39, 19–23, 9–10, 6–8; L of legs segments: I—Leg-1–5: 28–32, 38–42, 44–48, 60–65, 73–75; II—Leg-1–5: 35–39, 38–42, 45–52, 65–68, 80–87; III—Leg-1–5: 40–45, 40–45, 45–52, 65–70, 85–93.

Remarks. The presence of three solenidia situated in the tibia of legs II and III ( Figs 32–33 View FIGURES 32 – 34 ) is a unique characteristic of the larva of N. spinipes and will serve to separate it from all other known larvae of the genus. The tibia of leg II in larvae of the family Unionicolidae provides two solenidia, and the tibia of leg III one solenidion ( Prasad & Cook 1972, Wainstein 1980).