Morphological ontogeny of Zachvatkinibates latilamellatus (Acari: Oribatida Punctoribatidae), and comments on Zachvatkinibates Shaldybina Author Seniczak, Stanisław Author Seniczak, Anna Author Kaczmarek, Sławomir Author Marquardt, Tomasz Author Sarsenova, Bibigul text Zootaxa 2020 2020-09-28 4857 1 97 116 journal article 9063 10.11646/zootaxa.4857.1.6 939ce3b8-8672-4c66-a7e9-064951d5a13d 1175-5326 4396561 CC92CF3E-903A-43F1-BCEF-C51F628384DF Zachvatkinibates latilamellatus Bayartogtokh and Aoki, 1998 Morphology of adult Adults investigated herein ( Figs. 1–3a , 4–7 a–c) similar to those investigated by Bayartogtokh and Aoki (1998) , but see Remarks. Mean length (and range) of females 397.3±12.7 (384–416, n= 12) and males 380.3±11.3 (358–403, n= 18), mean maximum width (and range) of females 246.3±3.5 (238–248) and males 208.7±17.4 (191–234). Pedo- tecum I concave dorsally ( Fig. 3a ). Hypostomal setae h , m and a short and barbed ( Fig. 2 ). Genal tooth triangular, pointed ( Figs. 3a , 7b, 7c ), cheliceral setae cha longer and thicker than chb , both barbed ( Fig. 3b ). Palp setae sup , inf and l” on tibia finely barbed, other setae smooth ( Fig. 3c ), formula of palp seta 0-2-1-3-9(1). Trochanters III and IV and all femora flattened, tarsus I and tibia IV with thickened dorsal integument ( Figs. 5a, 5d , 7c ). Solenidia ω 1 and ω 2 on tarsus I of similar length. Formulae of leg setae [trochanter to tarsus (+ solenidia)]: I—1-5-3(1)-4(2)-20(2); II—1-5-3(1)-4(1)-15(2); III—2-3-1(1)-3(1)-15; IV—1-2-2-3(1)-12. Leg tarsi monodactylous. Remarks . Our individuals are larger than those investigated by Bayartogtokh and Aoki (1998) —mean length 346 (338–352), mean width 223 (216–226), sex not investigated. The shape and distribution of prodorsal and notogastral setae and porose areas are generally similar as in Bayartogtokh and Aoki (1998) . Diagnosis of juveniles Juveniles light brown, with two pairs of small, sclerotized depressions on gastronotum of larva (posterolateral to seta c 1 , and between setae c 1 and da ) and several pairs in nymphs (one pair posterolateral to seta c 1 , 3–4 pairs posterior to seta c 1 and 2–3 pairs posteromedial to seta la ). Larva with 12 pairs of gastronotal setae, including h 3 , all inserted on unsclerotized integument, nymphs with 15 pairs; setae of c -series inserted on individual sclerites, d -, l -, h -series and p 1 on gastronotal shield, and p 2 and p 3 on unsclerotized integument. In all juveniles, porose humeral organ is present. Description of juveniles Larva oval in dorsal view ( Fig. 8 ), light brown. Prodorsum subtriangular, prodorsal setae ro and in long, le of medium size ( Table 1 ), all barbed; seta ex short and smooth. Mutual distance between setal pair le about two times longer than between pair ro , and between setal pair in about four times longer than between pair ro , pair le inserted approximately midway between pairs ro and in . Opening of bothridium rounded, with posterolateral ridge, both- ridial seta clavate, with barbed head. FIGURE 1. Zachvatkinibates latilamellatus , female; (a) dorsal aspect, legs partially drawn, scale bar 50 μm, (b) shape of seta in (enlarged). FIGURE 2. Zachvatkinibates latilamellatus , adult, ventral aspect, legs partially drawn, scale bar 50 μm. FIGURE 3. Zachvatkinibates latilamellatus , adult; (a) lateral aspect, legs partially drawn, scale bar 100 μm; mouthparts, right side; antiaxial view, scale bars 20 μm, (b) chelicera (Trägårdh organ indicated in ‘transparent’ area), (c) palp. Gastronotum of larva ( Figs. 8 , 9a , 10a ) with 12 pairs of setae, including h 3 inserted lateral to anterior part of anal valves; most setae of medium size and barbed, except for short and smooth h 3 . Pygidial shield absent, all setae inserted on unsclerotized integument, length of setae of d - and l -series slightly increasing from anterior to posterior ( Table 1 ). Two small, sclerotized depressions present, posterolateral to seta c 1 , and between setae c 1 and da ( Figs. 8 , 10a ). Cupule ia posterior to seta c 3 , cupule im posterior to seta lm , cupule ip between setae h 1 and h 2 , cupule ih lateral to anterior part of anal opening. Opisthonotal gland opening posterolateral to seta lm , without dark sclerotized surrounding. Porose humeral organ small, placed anterior to seta c 3 ( Fig. 10a ). Paraproctal valves (segment PS) glabrous. Most leg setae barbed, seta ft” relatively long ( Fig. 11 ). FIGURE 4. Zachvatkinibates latilamellatus , adult, posterior aspect, scale bar 50 μm. TABLE 1. Measurements of some morphological characters of juvenile stages and adult of Zachvatkinibates latilamel- latus (mean measurements of 2–10 specimens in μm); Nd—not developed.
Morphological characters Larva Protonymph Deutonymph Tritonymph Adult
Body length 215 274 337 396 403
Body width 96 115 165 205 234
Length of prodorsum 69 75 103 108 97
Length of: seta ro 21 23 28 32 48
seta le 15 20 26 30 26
seta in 20 22 30 34 48
seta bs 28 30 37 40 44
seta c 1 16 20 23 27 Lost
seta c 2 15 18 21 25 20
seta c 3 21 22 31 35 Lost
seta da 18 13 15 18 Lost
seta dp 21 14 16 21 Lost
...Continued on the next page TABLE 1. (Continued)
Morphological characters Larva Protonymph Deutonymph Tritonymph Adult
seta la 19 14 18 25 18
seta lp 21 15 20 26 15
seta h 1 19 16 18 21 18
seta h 3 9 15 18 21 17
seta p 1 Nd 13 16 18 15
genital opening Nd 27 33 42 43
anal opening 48 65 72 85 71
Shape and colour of protonymph, prodorsal setae and bothridium as in larva; gastronotum with 15 pairs of setae ( p -series added, Fig. 9b ), and retained in subsequent nymphs ( Figs. 12a, 12b ). In all nymphs, gastronotal shield present, with 10 pairs of setae ( d -, l -, h -series, p 1 ), setae p 2 and p 3 inserted on unsclerotized integument; all setae relatively short and smooth. Setae of c -series of medium size and inserted on small individual sclerites, c 3 longer than other setae ( Table 1 ) and barbed, other setae smooth. In all nymphs, small, sclerotized depressions present on gastronotum, one posterior to seta c 2 , 3–4 posterior to seta c 1 and 2–3 posteromedial to seta la ( Figs. 7d , 10b , 13 , 14a, 14c ). In protonymph, one pair of genital setae appearing on genital valves, two pairs added in deutonymph and one pair in tritonymph ( Figs. 9b , 12a, 12b ), all short and smooth. In deutonymph, one pair of aggenital setae and three pairs of adanal setae appear, and remain in subsequent instars; all short and smooth. In protonymph and deutonymph, anal valves glabrous, in tritonymph two pairs of short and smooth anal setae present. In tritonymph, cupules ia and im as in larva, cupule ip between setae h 2 and h 1 , cupule iad lateral to anterior part of anal valves, cupules ips and ih displaced posterolateral and anterolateral to iad , respectively ( Figs. 12b , 13 ). Humeral organ large, rounded, porose, located anterior to seta c 3 , opisthonotal gland opening anteroventral to seta lp , without dark sclerotized surrounding ( Fig. 10b ). Legs of tritonymph stocky ( Figs. 7d , 14 , 15 ), with shorter barbs on setae pv on tibia II than in adult ( Figs. 5 , 6 , 7c ). Summary of ontogenetic transformations In the larva, the prodorsal setae ro and in are longer than seta le , in the nymphs these setae are of similar length, whereas in the adult seta in is longer than ro and le . Seta ex is short in all juveniles, but is of medium size in the adult. The bothridium is rounded in all instars, and in the adult it is covered by anterior tectum of notogaster. In all instars, the bothridial seta is clavate, with barbed head, but in the larva and adult the head is thicker than in the nymphs. The larva has 12 pairs of gastronotal setae, including h 3 , the nymphs have 15 pairs ( p -series appearing in the protonymph). The notogaster of adult loses five pairs of setae ( c 1 , c 3 and d -series), such that 10 pairs of notogastral setae remain. The formula of gastronotal setae in Z . latilamellatus is 12-15-15-15-10 (from larva to adult), the formula of epimeral setae are 3-1-2 (larva, including scaliform 1c ), 3-1-2-1 (protonymph), 3-1-2-2 (deutonymph) and 3-1-3-3 (tritonymph and adult). The formula of genital setae is 1-3-4-6 (protonymph to adult), and formula of aggenital setae is 1-1-1 (deutonymph to adult), and setal formula of segments PS-AN is 03333-0333-022. The ontogeny of leg setae and solenidia of Z . latilamellatus is shown in Table 2 .