Zealandozetes southensis, Ermilov, Sergey G., Minor, Maria A. & Behan-Pelletier, Valerie M., 2015

Ermilov, Sergey G., Minor, Maria A. & Behan-Pelletier, Valerie M., 2015, Zealandozetes southensis gen. nov., sp. nov. (Acari, Oribatida, Maudheimiidae) from alpine cushions plant in New Zealand, Zootaxa 4027 (1): -

publication ID

http://dx.doi.org/10.11646/zootaxa.4027.1.2

publication LSID

lsid:zoobank.org:pub:94FE880B-31C6-468A-9CF1-89EDE92AD78E

persistent identifier

http://treatment.plazi.org/id/F90C4C0D-3C62-4172-B71A-FC39B7103242

taxon LSID

lsid:zoobank.org:act:F90C4C0D-3C62-4172-B71A-FC39B7103242

treatment provided by

Plazi

scientific name

Zealandozetes southensis
status

sp. nov.

Zealandozetes southensis  sp. nov.

( Figs 1–51View FIGURE 1View FIGURE 2View FIGURE 3 – 5View FIGURE 6 – 9View FIGURES 10 – 13View FIGURE 14 – 17View FIGURE 18 – 19View FIGURES 20 – 25View FIGURES 26 – 29View FIGURES 39 – 41View FIGURE 48View FIGURE 49View FIGURE 50View FIGURE 51)

Diagnosis. As for genus.

Description of adult ( Figures 1 –13View FIGURE 1View FIGURE 2View FIGURE 3 – 5View FIGURE 6 – 9View FIGURES 10 – 13, 30–38, 48– 51) Measurements. Body length: 713 (holotype, female), 697–763 (11 paratypes, 6 females and 5 males); notogaster width: 415 (holotype), 381–431 (11 paratypes).

Integument. Body color dark brown. Surface of body, subcapitular mentum, gena, and legs porose, legs more weakly porose than rest of body. Pedotectum I striate. Lateral region of prodorsum between pedotectum I and bothridium covered with microgranular cerotegument (diameter of granules less than 1).

Prodorsum. Rostrum broadly rounded. Lamellae reduced to ridges forming indistinct X -like structure in some specimens. Ridge located between lamellar ridges transverse, thick. Rostral seta (ro, 73–82) slightly barbed. Lamellar (le, 123–139), interlamellar (in, 164–180) and exobothridial (ex, 73–86) setae thickened, straight, heavily barbed. Bothridial setae (bs, 36–42) clavate, with stalk (20–24) longer than barbed head (16–18). Genal tooth (gt) strong, elongate triangular. Tutorium (tu) developed as curved ridge, 98–106 long. Porose area Aj present. Dorsophragmata (D) separated.

Notogaster. Anterior notogastral margin almost straight. Humeral region rounded. Pteromorph reduced to strongly developed pleural carina (pcar). Ten pairs of notogastral setae (p 1 – p 3, 69– 77; others, 86–94) thickened, straight, heavily barbed. Four pairs of very small saccules present. Lyrifissures (ia, im, ih, ip, ips) and opisthonotal gland opening (gla) clearly visible.

Gnathosoma  . Subcapitulum longer than wide (172–176 × 127–131). Subcapitular setae setiform, barbed; a (32–36) shorter than m (49–57) and h (45–53). Adoral setae (or 1, or 2, 24– 28) setiform, slightly barbed. Palp (118– 131) with setation 0–2 – 1–3 – 9 (+ω). Solenidion straight, blunt-ended, attached to eupathidium. Axillary saccule elongated (10–12). Chelicera (184–188) with two thickened, barbed setae; cha (49–57) longer than chb (32–36). Antiaxial part with one or two minute teeth. Trägårdh’s organ (Tg) elongate, tapered.

Epimeral and lateral podosomal regions. Porose area Am diffuse; Ah expressed as heavily sclerotized concave saccule proximally, about 25 at greatest depth, extending into tubule distally, about 37. Porosity on this tubule not evident. Sejugal apodemes almost fused medially. Apodeme 3 directed to median part of sejugal apodeme. Setae 3 c and 4 c are doubled in some specimens. Setae thin, slightly barbed; 1 a, 1 c, 2 a, 3 a, 4 b (28–41) shorter than others (49–57). Discidium (dis) very small, triangular, visible in dissected specimens. Pedotectum I with ridges curving anteriorly. With about six dorsoventral ridges present between pedotectum I and acetabulum II and ridges posterior to acetabula III and IV.

Anogenital region. Six pairs of genital (g 1 – g 6) and one pair of aggenital (ag) setae similar in length (32–41), setiform, slightly barbed. Two pairs of anal setae (an 1, an 2, 41– 53) slightly thickened, straight, barbed. Three pairs of adanal setae (ad 1 – ad 3, 61– 73) thickened, straight, heavily barbed. Lyrifissure iad in paraanal position. Ovipositor elongated (213–225 × 65), lobes (82–90) shorter than length of distal section (beyond middle fold; 131–135). Each of three lobes with four straight, smooth setae; ψ 1 ≈ τ 1 (61–69) longer than ψ 2 a (41), τ a ≈ τ b (32–36) and ψ 2 b ≈ τ c (20).

Six coronal setae (k, 20) present, straight, smooth. Postanal porose area expressed as large concave porose depression, about 43 × 5, extending into large lobed saccules laterally; structure about 125 wide, 48 deep.

Legs. Tarsi with three claws, medial claw larger than lateral claws, all claws barbed on dorsal side. Femora I – IV and trochanters III, IV with dorso-paraxial porose areas. Additionally, femora III, IV with ventral porose areas (pav). Tibiae I and II with weakly defined ventral porose areas (not illustrated). Formulas of leg setation and solenidia: I (1–5 – 3–4 – 20) [1–2 – 2], II (1–5 – 3–4 – 15) [1 – 1–2], III (2–3 – 1–3 – 15) [1 – 1 –0], IV (1–2 – 2–3 – 12) [0–1 – 0]; homology of setae and solenidia indicated in Table 1. Famulus (ɛ) short, straight, blunted. Some setae thickened, straight, heavily barbed ( Figs 10–13View FIGURES 10 – 13).

*Roman letters refer to normal setae, Greek letters refer to solenidia (except ɛ—famulus). One apostrophe (') marks setae on anterior and double apostrophe (") marks setae on posterior side of the given leg segment. Parentheses refer to a pair of setae. Setae are listed only for the instar in which they first appear.

Description of juvenile instars ( Figs 14 –29View FIGURE 14 – 17View FIGURE 18 – 19View FIGURES 20 – 25View FIGURES 26 – 29, 39View FIGURES 39 – 41 – 47)

Measurements. Length: larva 298–332, protonymph 381–398, deutonymph 498–531, tritonymph 597–630. Width: larva 190–199, protonymph 215–232, deutonymph 282–332, tritonymph 332–348.

Integument. Prodorsum, subcapitulum, epimeral region, and gastronotal sclerite sclerotized, brownish in color, gastronotal sclerite most heavily sclerotized; legs lightly sclerotized; all sclerotized integument porose. Lateral, sternal and anogenital regions light yellowish to colorless.

Prodorsum. Relatively short, about half length of gastronotic region. Rostrum rounded. Rostral seta thin, barbed. Lamellar, interlamellar and exobothridial setae thickened, straight, heavily barbed. Bothridial seta clavate, with longer stalk and shorter, barbed head. Prodorsal setae measurements given in Table 2.

Gastronotic region. Gastronotic sclerite bearing setae of d, l series and h 1 in larva; c series and h 2, h 3 on unsclerotized integument. Gastronotic sclerite of nymphs bearing setae of d, l and h series, and setae p 1; bearing or not seta c 1 anteriorly; setae c 2, c 3 and p 2, p 3 on unsclerotized integument. Sclerite with darker circular regions laterally and posteriorly, and band of four to five pairs of dark circular regions posterior to setae da. Humeral organ (ho) expressed as narrow, shallow depression with cupule-like opening, positioned lateral to c 3. Larva with 12 pairs, nymphs with 15 pairs of thickened, straight, heavily barbed setae. Cupules ia, im and ip visible. Gastronotic setae measurements given in Table 2.

Gnathosoma  . All subcapitular (h, m, a) and adoral (or 1, or 2) setae simple, slightly barbed. Palp setal formula of all instars 0–2 – 1–3 – 9 +. Palpal solenidion slightly thickened, blunt-ended, pressed to eupathidium acm. Palp setae (except dorso-distally on tarsus) barbed. Cheliceral setae setiform, barbed; cha longer than chb. Antiaxial surface with one small tooth. Gnathosomal setae measurements given in Table 3. Axillary saccule present in all instars.

Epimeral region. Setal formulas for successive epimeres: larva 3 – 1–2 (third setae of first epimere forms protective scale over respective Claparède’s organs (Cl )); protonymph 3 – 1–2 – 1; deutonymph 3 – 1–2 – 2, tritonymph 3 – 1–3 – 3. Setae setiform, slightly barbed; their measurements given in Table 2.

Anogenital region. Bordered by 2 diagonal, slightly convergent posteriorly directed folds. Ontogenetic setal formulas (larva to tritonymph, respectively): aggenital 0– 0–1 – 1, adanal 0– 0–3 – 3, anal 0–0– 0–2. Larva with 2 pairs of paraproctal alveoli, protonymphs with 3 pairs of adanal alveoli, deutonymphs with 2 pairs of anal alveoli. Genital, aggenital and anal setae (except paraproctal) thin, barbed. Adanal setae thickened, straight, heavily barbed. Opisthonotal gland openings small. Anogenital setae measurements given in Table 2.

FIGURES 30–38. Zealandozetes southensis  sp. nov., dissected adult, transmitted light microscopy images: 30 —basal part of prodorsum and anterior part of notogaster, dorsal view; 31 —bothridial seta and bothridium; 32 —genal tooth; 33 —pleural carina; 34 —saccule Sa; 35 —saccule S 1; 36 —anterior part of left anal plate and anal seta an 2; 37 —adanal seta ad 1; 38 —anterior part of femur III, right, antiaxial view. Scale bars (30, 33) 50 Μm, (31, 32, 34 – 28) 20 Μm.

Legs. Claw of each leg slightly serrate dorsally. Leg formulas: larva: I (0– 2 – 3 – 3–16) [1 – 1 – 1], II (0– 2 – 2 – 2–13) [1 – 1 – 1], III (0– 2 – 1 – 1–13) [1 – 1 –0]; protonymph: I (0– 4 – 2–3 – 16) [1 – 1–2], II (0– 4 – 2–3 – 13) [1 – 1 – 1], III (1–2 – 1 – 1– 13) [1 – 1 –0], IV (0–0–0– 0–7) [0–0–0]; deutonymph: I (1–4 – 2–4 – 16) [1–2 – 2], II (1–4 – 2–4 – 13) [1 – 1–2], III (2–3 – 1–2 – 13) [1 – 1 –0], IV (1–2 – 2–3 – 12) [0–1 –0]; tritonymph: I (1–4 – 3–4 – 18) [1–2 – 2], II (1–4 – 3–4 – 15) [1 – 1–2], III (2–3 – 1–3 – 15) [1 – 1 –0], IV (1–2 – 2–3 – 12) [0–1 –0]. Anteroventral porose area present on tibiae I and II in all instars. Specific ontogeny of leg setae and solenidia given in Table 1.

Type deposition. The holotype and two paratypes are deposited in the New Zealand National Arthropod Collection, Auckland, New Zealand; three paratypes are deposited in the collection of the Senckenberg Institution, Frankfurt, Germany; six paratypes and all juvenile instars are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology. The specific name southensis  refers to the place of origin, the South Island ( New Zealand).

FIGURES 42–47. Zealandozetes southensis  sp. nov., juveniles, transmitted light microscopy images: 42 —larva, dorsal view; 43 —posterior part of protonymph, dorsal view; 44 —posterior part of protonymph, ventral view; 45 —larva, bothridial and exobothridial setae; 46 —larva, humeral region with seta notogastral seta c 3 and humeral region; 47 —larva, lyrifissure im and medio-basal part of notogastral seta lm. Scale bars (42) 100 Μm, (43, 44) 50 Μm, (45–47) 20 Μm.

Habitat. The new species was found during a study of microarthropods of the high alpine zone (1600–1900 m a.s.l.) of three mountain ranges in the Central Otago region, South Island, New Zealand: Old Man’s Range, Pisa Range and The Remarkables. In each locality, soil cores were collected from alpine cushion fields (22–24 cores), vegetated snowbanks (15 cores) and alpine bogs (15 cores) using a 5 × 5 cm stainless steel corer. Samples included the entire vegetation layer, and the soil to a depth of five cm. Microarthropods were extracted into 75 % ethanol in modified Tullgren-Berlese extractors for a week.

The Central Otago ranges are relatively recent fault-block mountains which have uplifted during the past ~ 5 million years due to accelerated movement along a series of faults to the south-east from the Alpine Fault, the South Island tectonic boundary between the Pacific and the Australian plates. Prior to the mountain-building phase of the Pliocene-Pleistocene, this area is thought to have been low-lying without an alpine zone ( Cooper & Millener 1993). The main parental material in the area is the metamorphic schist rock.

In the alpine cushion fields, the top layer of the soil is a fine-textured sandy loam 2–30cm in depth, rich in organic matter, which is underlain by coarse schist material ( Mark 1994). There is a complex surface pattern of cryogenic earth hummocks and stripes 15–30 cm in height, with furrows in between ( Mark 1994). The vegetation on crests of hummocks and stripes is dominated by dwarf cushion plants Dracophyllum muscoides Hook.  f. ( Ericaceae  ) and Raoulia  sp. ( Asteraceae  ; most likely Raoulia hectori Hook.  f.); bare soil, some herbaceous plants, and lichens are found in furrows ( Mark & Bliss 1970; Scott et al. 2008).

The climate of the high alpine zone is characterized by low mean annual air and soil temperatures (ca. 2 degrees C), a relatively small annual temperature range and frequent freeze-thaw cycles ( Mark & Bliss 1970). The mean annual precipitation is about 1600 mm (rain and snow), and soil moisture remains close to field capacity throughout the growing season (December to March) ( Mark & Bliss 1970). Mean daily soil temperatures are continuously below freezing from May to October. February is the warmest month, but freezing occurs in every month of the year ( Scott et al. 2008).

Zealandozetes southensis  sp. nov. was found in cushion fields and snowbanks of Pisa Range (at elevations ranging 1700–1800 m a.s.l.) and in cushion fields of The Remarkables (at elevations 1830–1880 m a.s.l.) in high frequency and abundance. In Pisa Range, their mean density in cushion fields was 3,120 ind. m - 2, max. 11,600 ind. m - 2. In The Remarkables the mean density in cushion fields was 4,080 ind. m - 2, max. 6,800 ind. m - 2. There was no difference in abundance for samples taken within cushion plants on crests of earth hummocks, or in the soil in furrows. Zealandozetes southensis  sp. nov. was absent in the Old Man’s Range.

TABLE 1. Development of leg setation of Zealandozetes southensis sp. nov. *

  Trochanter Femur Genu    
      (l), v', φ1 (ft), (tc), (p), (u), (a), s, (pv), (pl), ɛ, ω1
Deutonymph        
Deutonymph        

TABLE 2. Lengths of body setae of Zealandozetes southensis sp. nov. during ontogeny *

    36–40 (stalk: 20–22, head: 16–18) 40–44 (stalk: 22–24, head: 18–20)  
Exobothridial        
        1b, 3b, 3c, 4a, 4c: 32– 36; others: 24

TABLE 3. Size changes in the gnathosoma of Zealandozetes southensis sp. nov. during ontogeny.

    Protonymph Deutonymph Tritonymph
Length of setae m and h        
  98–102