Trichoribates naltschicki ( Shaldybina, 1971 )

Seniczak, Stanisław, Seniczak, Anna & Kaczmarek, Sławomir, 2019, Morphological ontogeny of Trichoribates naltschicki (Acari: Oribatida: Ceratozetidae), Zootaxa 4717 (1), pp. 47-64 : 49-54

Trichoribates naltschicki ( Shaldybina, 1971)

( Figs. 1–11 )

Latilamellobates naltschicki Shaldybina, 1971 : Tarman 1983; Karppinen et al. 1987; Shtanchaeva 2001; Bayartogtokh 2010. Viracochiella (Latilamellobates) naltschicki: Subías 2004 .

Murcia (Latilamellobates) naltschicki: Subías 2008 .

Trichoribates (Latilamellobates) naltschicki: Subías 2009, 2019 .

Trichoribates naltschicki: Murvanidze and Mumladze 2016 .

Morphology of adult

Adults ( Figs. 1–4 ) similar to those investigated by Shaldybina (1971) and Bayartogtokh (2010), but see Remarks. Body size of females: mean length (range) 479.7 (455–494, n= 6), width 282.1 (267–293); males: mean length 464.8 (455–475, n= 5), width 269.8 (260–273). Cheliceral seta cha longer than chb, both barbed ( Fig. 3b ). Most palp setae relatively long and barbed, tarsal setae short ( Fig. 3c ). Trochanters III and IV and all femora flattened and with ventral carina, porose areas present on paraxial part of trochanters III and IV and dorsoventral part of all femora. Seta l” on genua I and II and all tibiae thick, spine-like and barbed ( Fig. 4 ). 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—2-2 -1(1)-3(1)-15; IV—1-2 -2-3(1)-12. Legs heterotridactylous.

Remarks. The individuals of this study are smaller than those studied by Shaldybina (1971) —length 452–516, width 310–387 (sex not determined), but are larger than those investigated by Bayartogtokh (2010) —length 433– 445, width 249–258 (sex not determined). Our individuals and those studied by Shaldybina have four pairs of geni- tal setae (versus 4–5 pairs in Bayartogtokh). Leg setae bv” and v’’ on femora I and II are shorter than seta d in this study (versus as long or longer than d in Shaldybina), which may reflect regional variability of this species.

Diagnosis of juveniles

Juveniles elongated, unpigmented. Larva with 12 pairs of gastronotal setae, including h 3, nymphs with 15 pairs. In larva, pygidial shield absent, in nymphs gastronotal shield bears 10 pairs of notogastral setae (d -, l -, h -series, p 1). In all juveniles, most gastronotal setae of medium size, except for long lp and h 1 in larva, and long h 1 in nymphs. In all juveniles, humeral organ and dark pigmented cuticle around gla opening absent. Legs monodactylous.

Description of juveniles

Larva elongated ( Fig. 5 ) and unpigmented. Prodorsum subtriangular, seta ro longer than le, but shorter than in ( Table 2 ), all barbed; seta ex short and smooth. Mutual distance between setal pair le about twice longer than between pair ro and between setal pair in about four times longer than between pair ro. Pair le inserted closer to in than to ro. Opening of bothridium rounded, bothridial seta clavate, with barbed head.

Gastronotum of larva ( Figs. 5 , 6a , 7a ) with 12 pairs of setae, including h 3 inserted lateral to medial part of anal valves. Gastronotum with rare transverse folds, pygidial shield absent. Most gastronotal setae of medium size ( Table 2 ), except for long lp and h 1; most barbed, h 2 and h 3 smooth. Humeral organ absent. 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 end of anal opening. Opisthonotal gland opening without dark surrounding, anterolateral to seta lp. Paraproctal valves (segment PS) glabrous. Most leg setae finely barbed, seta d on all femora with longer barbs ( Fig. 8 ).

Protonymph elongated, prodorsal setae le and ex relatively longer, and bothridial seta slimmer than in larva and seta ex barbed. Gastronotum with 15 pairs of setae due to appearance of p -series ( Fig. 6b ), retained by subsequent nymphs ( Figs. 9a, 9b ). In protonymph, seta p 1 of medium size and barbed and other setae of this series short and smooth; in deutonymph and tritonymph, all setae of p -series longer and barbed. Gastronotal shield present, with 10 pairs of setae (d -, l -, h -series, p 1), other setae on unsclerotized integument. In protonymph, one pair of genital setae appearing on genital valves, and one pair added in deutonymph and tritonymph each; all short and smooth. In deutonymph, one pair of aggenital seta and three pairs of adanal setae appearing ( Fig. 9a ), retained in tritonymph ( Fig. 9b ), seta ag short and smooth, adanal setae with small barbs. In protonymph and deutonymph, anal valves glabrous, in tritonymph with two pairs of small anal setae. In all nymphs, most gastronotal setae of medium size, except for long h 1 ( Figs. 6b , 7b , 9 , 10 ). In tritonymph, cupules ia and im placed as in larva, cupule ip between setae h 2 and p 1, cupule iad lateral to anterior part of anal valves, cupules ips and ih displaced lateral to iad ( Figs. 7b , 9a, 9b ). Opisthonotal gland opening placed as in larva, and without surrounding dark area. Humeral organ absent. Leg segments of tritonymph stockier than in adult, but all setae thin and most setae with short barbs ( Fig. 11 ).

Summary of ontogenetic transformations

In all instars of T. naltschicki , the prodorsal seta in is long, setae ro and le are of medium size (le as long or longer than ro) and seta ex is short, but in the larva ro is longer than le. In all instars, the bothridium is rounded, but in the adult it has lateral scales, with inner scale longer than outer scale. In all instars, the bothridial seta is clavate, but in the larva and adult, the head of this seta is thicker than in the nymphs. The larva has 12 pairs of gastronotal setae, including h 3, the nymphs have 15 pairs. The notogaster of the adult loses setae c 1, c 3 and d -series, so that 10 pairs remain. Formula of gastronotal setae in T. naltschicki is 12-15-15-15 -10 (from larva to adult).Formulae of epimeral setae is 3-1-2 (larva), 3-1-3-1 (protonymph), 3-1-3-2 (deutonymph) and 3-1-3-3 (tritonymph and adult). Formula of genital setae is 1-2-3-4 (protonymph to adult), that of aggenital setae is 1-1-1 (deutonymph to adult), and formula of segments PS−AN is 03333-0333-022. The ontogeny of leg setae and solenidia in T. naltschicki is similar to that of T. polaris studied by Behan-Pelletier (1985), except for seta v’ on genua I and II that is added in the adult (versus in the tritonymph of T. polaris ), setae l” and v” on tibia II that are added in the tritonymph and adult, respectively (versus in the deutonymph and tritonymph of T. polaris , respectively), and seta v’’ on tibiae III and IV that is added in the adult (versus in the tritonymph of T. polaris ).

Figures

FIGURE 1. Trichoribates natschicki, adult, female. (a) Dorsal aspect, legs partially drawn, scale bar 50 μm, (b) shape of seta le, (c) shape of seta h2 (both enlarged).

FIGURE 2. Trichoribates naltschicki, adult, female, ventral aspect, legs partially drawn, scale bar 50 μm.

FIGURE 3. Trichoribates natschicki, adult. (a) Female, lateral aspect, legs partially drawn, scale bar 50 μm; mouthparts, right side, antiaxial aspect, scale bars 20 μm, (b) chelicera (Trägårdh organ indicated in ‘transparent’ area), (c) palp.

FIGURE 4. Trichoribates natschicki, leg segments of adult (part of femur to tarsus), right side, antiaxial aspect, setae on the opposite side not illustrated, but indicated in the legend, scale bar 20 μm. (a) Leg I, tarsus (pl’), apical parts of solenidion ω1 and setae tc above this solenidion or setae; (b) leg II, tarsus (pv’); (c) leg III, tibia (v’’); (d) leg IV, tibia (v’’).

FIGURE 5. Trichoribates naltschicki, larva. (a) Dorsal aspect, legs partially drawn, scale bar 50 μm, (b) shape of seta dp (enlarged).

FIGURE 6. Trichoribates naltschicki, legs partially drawn, ventral aspect of hysterosoma, scale bar 50 μm. (a) Larva, (b) protonymph.

FIGURE 7. Trichoribates naltschicki, lateral aspect, legs partially drawn, scale bars 50 μm. (a) Larva, (b) tritonymph.

FIGURE 8. Trichoribates natschicki, leg segments of larva (part of femur to tarsus), right side, antiaxial aspect, setae on the opposite side not illustrated, but indicated in the legend, scale bar 10 μm. (a) Leg I, tarsus (pv’); (b) leg II, tarsus (pv’); (c) leg III.

FIGURE 9. Trichoribates naltschicki, ventral aspect of hysterosoma, legs partially drawn, scale bars 50 μm. (a) Deutonymph, (b) tritonymph.

FIGURE 10. Trichoribates natschicki, tritonymph. (a) Dorsal aspect, legs partially drawn, scale bar 50 μm, (b) seta lp (enlarged).

FIGURE 11. Trichoribates natschicki, leg segments of tritonymph (part of femur to tarsus), right side, antiaxial aspect, seta on the opposite side not illustrated, but indicated in the legend, scale bars 20 μm. (a) Leg I, tarsus (pl’); (b) leg II; (c) leg III; (d) leg IV.

Tables

TABLE 2. Measurements of some morphological characters of juvenile stages and adult of T. naltschicki (mean measurements of 2–11 specimens in μm, according to stage structure).

Morphological character	Larva	Protonymph	Deutonymph	Tritonymph	Adult
Body length	241	304	384	449	462
Body width	96	128	165	218	281
Length of prodorsum	74	96	114	136	112
Length of: seta bs	23	26	30	32	42
seta ro	28	30	43	48	67
seta le	16	30	40	62	65
seta in	37	56	62	80	86
seta c 1	15	35	27	38	Lost
seta c 2	12	14	22	32	40
seta c 3	18	26	32	46	Lost
seta da	15	18	21	26	Lost
seta dp	23	26	29	40	Lost
seta la	14	19	26	32	32
seta lp	23	27	40	56	24
seta h 1	27	42	54	77	32
seta h 3	10	29	46	54	37
seta p 1	Not developed	16	32	51	32
seta p 3	Not developed	8	24	38	24
genital opening	Not developed	27	37	46	59
anal opening	40	62	77	99	75