Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023

Ermilov, Sergey G. & Sharapov, Denis V., 2025, Nymphal instars of Pergalumna cienfuegosensis (Acari, Oribatida, Galumnidae), Persian Journal of Acarology 14, pp. 437-446 : 438-444

Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023

( Figs. 1–16 )

Description of nymphal instars

Measurements – Total lengths: PN: 199–232; DN: 232–255; TN: 277–315. Total widths: PN: 199–232; DN: 232–255; TN: 277–315.

Integument ( Figs. 1–6 , 10–12 , 16 ) – Body cuticle pale to grey; legs and subcapitulum usually slightly darker. Surface densely microgranulate; granules slightly visible, but on prodorsum as well as on gastronotic and circumgenital macrosclerites larger and clearer; anterolateral part of gastronotic region between setae c 1 and c 2 with sparse folds; dorsal side of leg trochanter IV heavily granulate.

Prodorsum ( Figs. 1–5 , 10–12 ) – Relatively short, about 1/2 length of gastronotic region (in lateral aspect). Rostrum tripartite (not visible in dorsal aspect, but well visible in frontal aspect). Lateral ridges well developed and fused by transverse, thin medial ridge concave medially. Rostral (PN: 17–19; DN: 19–22; TN: 22–26) and lamellar (PN: 24–26; DN: 26–30; TN: 30–34) setae setiform, barbed; interlamellar seta (PN: 7; DN: 7–9; TN: 11) setiform, thin, slightly barbed; bothridial seta (PN, DN: 37–41; TN: 41–45) clavate, with long stalk and shorter, barbed head; exobothridial seta (PN, DN: 11; TN: 15) setiform, thin, nearly smooth. Interbothridial region with three separate pairs of muscle sigillae (two pairs located medially, in longitudinal row; one pair located laterally).

Gastronotic region ( Figs. 1–4, 6 , 10–12 ) – Anterior gastronotic region distinct. Dorsal region with large, well-bordered shield (macrosclerite); in TN, posterior part of macrosclerite concave. Posterior half with slightly developed transverse band represented by numerous, dense, thin ridges. Sclerites on lateral side of body (posterior to seta c 3) not visible, but large, amorphous, slightly pigmented region observed. Porose areas absent. Fifteen pairs of gastronotic setae, with 10 pairs ( da, la, dm, lm, dp, lp, h 1 – h 3, p 1) located on macrosclerite; c 1 vestigial, inserted on small sclerite; c 2 (PN, DN, TN: 7) and c 3 (PN, DN, TN: 9) setiform, thin, slightly barbed, inserted on small sclerites; da, la, dm, lm, dp, lp, h 1 – h 3, and p 1 – p 3 represented by alveoli except setiform, thin, smooth p 1 (7), p 2 (4), and p 3 (4) in PN. Cupules ( ia, im, ip) slightly visible; im and ip located marginally on macrosclerite.

Gnathosoma ( Figs. 7–9 ) – Subcapitulum slightly shorter (or distinctly shorter in dissected specimens) than wide: PN: 45–49 × 49–52; DN: 49–52 × 52–60; TN: 60–64 × 64–71; mentum with one pair of lateral triangular tubercles; three pairs of subcapitular setae ( a: PN: 7; DN: 7–9; TN: 9– 11; m, h: PN: 4; DN: 4–7; TN: 7–9) setiform, slightly barbed; two pairs of adoral setae (PN: 2; DN: 4–6; TN: 7) setiform, roughened. Palp lengths: PN: 37; DN: 45–49; TN: 56; setation: 0-2-1-3- 9(+ω); solenidion bacilliform, attached to eupathidium, both located on tubercle; postpalpal seta (PN, DN: 2; TN: 4) spiniform, smooth; axillary saccule small, well visible. Chelicera lengths: PN: 64; DN: 77–82; TN: 90–97; setae ( cha: PN: 19; DN: 22; TN: 26–28; chb: PN: 11; DN: 15; TN: 17– 19) setiform, barbed.

Epimeral and lateral podosomal regions ( Figs. 5 , 10–12 ) – Setal formulas for epimeres: PN: 3-1-2-1; DN: 3-1-2-2; TN: 3-1-2-3; epimeral setae (PN, DN: 1b, 1c, 3b: 7, others: 4; TN: 1b, 1c, 3b, 4c: 7–11, others: 4–7) setiform, thin, roughened ( 1b, 1c, 3b, 4c) or smooth (other setae). Large lamina between acetabula I and II. Tooth between acetabula II and III.

Anogenital region ( Figs. 5 , 10–12 ) – Circumgenital macrosclerite present, but slightly bordered. Aggenital region with slightly developed transverse band represented by numerous, dense, thin ridges. Ontogeny of genital (PN, DN: 4; TN: 7), aggenital (DN: 4; TN: 7), adanal (DN: 4; TN: 7), and anal (TN: 4) setal formulas, from PN to TN: 1-3-5, 0-1-1, 0-3-3, 0-0-2, respectively; all setae setiform, thin, smooth. Cupules ih, ips, and iad appearing in normal ontogenetic pattern. Opisthonotal gland opening distinct.

Legs ( Figs. 13–16 ) – Claw of each leg slightly barbed on dorsal side. Trochanter IV with small,

but distinct dorsal tooth. Porose area not visible on segments. Leg setal formulas: PN: I (0-2-2-3-16) [1-1-2], II (0-2-2-2-13) [1-1-1], III (0-2-1-1-13) [1-1-0], IV (0-0-0-0-7) [0-0-0]; DN: I (0-4-2-3-16) [1-2-2], II (0-4-2-2-13) [1-1-2], III (1-2-1-1-13) [1-1-0], IV (0-1-2-1-12) [0-1-0]; TN: I (0-4-3-4-18) [1-2-2], II (0-4-3-3-15) [1-1-2], III (1-2-1-2-15) [1-1-0], IV (0-1-2-2-12) [0-1-0]; AD: I (1-4-3-4-20) [1-2-2], II (1-4-3-4-15) [1-1-2], III (1-2-1-3-15) [1-1-0], IV (1-1[or 2]-2-2[or 3]-12) [0-1-0]; homology of setae and solenidia indicated in Table 1.

Remarks

Generally, the known juvenile instars within Galumnidae are quite uniform, differing only in a few characters (e.g., body size; length of prodorsal setae; shape of the rostrum; length of some gastronotic setae; development of porose areas and macro- and microsclerites; etc.). As mentioned above, juveniles of most Pergalumna are still unknown except for five species ( Norton and Ermilov 2014, 2024). The nymphal instars of P. cienfuegosensis can be easily distinguished from those of other Pergalumna (only TN in P. emarginata ) as follows.

Nymphs of P. cienfuegosensis differ from those of P. ekaterinae (see Páez et al. 2019, but due to insufficient description, some characters cannot be compared) in body size (lengths: PN: 199– 232; DN: 232–255; TN: 277–315 versus PN: 239; DN: 312; TN: 392); the presence (versus absence) of transverse, concave medial prodorsal ridge; the length and the morphology of the interlamellar seta (short, setiform versus long, thickened); the morphology of the exobothridial seta (setiform versus thickened); the absence (versus presence) of porose areas on the gastronotum; distinctly longer gastronotic seta p 1 in PN; and the development of leg setation.

Nymphs of P. cienfuegosensis differ from those of P. emarginata (as P. omniphagous – see Rockett and Woodring 1966, but due to insufficient description, many characters cannot be compared) in the presence (versus absence) of transverse, concave medial prodorsal ridge; the length of the interlamellar seta (short versus medium-sized); and distinctly shorter gastronotic seta c 3.

Nymphs of P. cienfuegosensis differ from those of P. myrmophila (see Bayartogtokh and Ermilov 2017) in body size (length: PN: 199–232; DN: 232–255; TN: 277–315 versus PN: 315– 365; DN: 415–464; TN: 531–564); the shape of the rostrum (tripartite versus rounded); the presence (versus absence) of transverse, concave medial prodorsal ridge; the length of the interlamellar seta

(short versus medium-sized); the length of the gastronotic seta c 2 (well-developed, slightly shorter than c 3 versus minute); distinctly longer gastronotic seta p 1 in PN; the presence (versus absence) of one pair of tubercles on subcapitular mentum; the number of setae on the epimere III (two pairs versus three pairs); and the development of leg setation.

Nymphs of P. cienfuegosensis differ from those of P. nervosa (see Sengbusch 1954; Seniczak 1972; Grishina 1977; Seniczak et al. 2012, but due to insufficient description, some characters cannot be compared) in body size (lengths: PN: 199–232; DN: 232–255; TN: 277–315 versus PN: 325–407; DN: 429–486; TN: 582–593); the presence (versus absence) of transverse, concave medial prodorsal ridge; the length of the interlamellar seta (short versus medium-sized); distinctly shorter gastronotic seta c 3; and the development of leg setation.

Nymphs of P. cienfuegosensis differ from those of P. striatiprodorsum (see Bayartogtokh and Ermilov 2017) in body size (lengths: PN: 199–232; DN: 232–255; TN: 277–315 versus PN: 298– 315; DN: 398–415; TN: 498–564); the shape of the rostrum (narrow versus broad incisions); the presence (versus absence) of transverse, concave medial prodorsal ridge; the length of the interlamellar seta (short versus medium-sized); the shape of the posterior part of the gastronotic shield (concave versus rounded); the length of the gastronotic seta c 2 (well-developed, slightly shorter than c 3 versus minute); the presence (versus absence) of one pair of tubercles on the subcapitular mentum; the number of setae on epimere III (two versus three pairs); and the development of leg setation.

Figures

Figures 1–3. Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023 (juvenile instars) – 1. Protonymph, dorsal view (part of right half omitted); 2. Deutonymph, dorsal view (part of right half omitted); 3. Tritonymph, dorsal view.

Figures 4–9. Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023 (juvenile instars) – 4. Protonymph, anterior part of prodorsum, frontal view; 5. Protonymph, right lateral view (gnathosoma and legs omitted); 6. Protonymph, posterior view; 7. Tritonymph, dissected subcapitulum, ventral view; 8. Tritonymph, dissected palp, right, antiaxial view; 9. Tritonymph, dissected chelicera, left, paraxial view.

Figures 10–12. Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023 (juvenile instars) – 10. Protonymph, ventral view (gnathosoma, legs, and part of left half omitted); 11. Deutonymph, ventral view (gnathosoma, legs, and part of left half omitted); 12. Tritonymph, ventral view (gnathosoma and legs omitted).

Figures 13–16. Pergalumna cienfuegosensis Ermilov, Kolesnikov, Kontschán & Klimov, 2023 (tritonymph) – 13. Leg I, right, antiaxial view; 14. Leg II, right, antiaxial view; 15. Leg III, left, antiaxial view; 16. Leg IV, left, antiaxial view.