Tectocepheus sarekensis (Tragardh, 1910)

Pfingstl, T. & Krisper, G., 2011, No Difference In The Juveniles Of Two Tectocepheus Species (Acari: Oribatida, Tectocepheidae), Acarologia 51 (2), pp. 199-218 : 201-207

Tectocepheus sarekensis

Larva — Body length (N = 8): 169 – 188 µm, average 181 µm.

Gastronotic region ( Figure 2a ) — 12 pairs of notogastral setae present. Setae c 1 – 3, da – dp, la – lp and h 1 small and robust. Cupule im situated posterior to seta lm. Cupule ia lateral on a level with sejugal furrow.

Ventral region of the idiosoma ( Figure 2b ) — epimeral setation (I-III): 3-1-2. Setae 1a, 2a, 3a arranged medially. Seta 1b situated in the middle of epimeral plate I on a level with Claparède organ. Seta 1c shaped valve like protecting Claparede´s organ. Seta 3b close to trochanter III. Porous areas located on apodemes 2, sejugal and 3. Seta h 3 short, seta h 2 conspicuously long and solid, both acuminate. Cupule ih located antero-laterally to anal aperture and cupule ip lateral near h 2. Small opisthonotal glands situated laterally on a level with seta h 2.

Legs ( Figures 3a–c ) — setation see Table 1.

Protonymph — Body length (N = 18): 185 – 231 µm, average 221 µm.

Gastronotic region ( Figure 4a ) — 15 pairs of notogastral setae, setae p 1, p 2 and p 3 added in this stage.

Ventral region of idiosoma ( Figure 4b ) — cupule ips located anterior to anal aperture. Cupule ih dis- placed laterally, next to opisthonotal gland. Setae p 3 and p 2 short and acuminate, flanking anal opening. Seta p 1 same shape, situated posteriorly. Genital region bearing one pair of genital setae. Epimeral setation (I-IV): 3-1-2-1. Seta 1c near lateral margin of epimeral plate I, close to trochanter. Seta 4a placed on epimeral plate IV close to median posterior margin. Median divided mentotectum looking like transverse incision on anterior median margin of epimeral plate I. Median lobes of this incision variable, rounded or tapered; shape of these lobes sometimes also varying between left and right. From this stage irregularly shaped round and slightly elevated spots dispersed over median area between epimeral plates.

Legs ( Figures 5a–d ) — setation see Table 1.

Deutonymph — Body length (N = 22): 231 – 293 µm, average 266 µm.

Prodorsum — median prodorsal ridges assuming shape of definitive lamellae. Translamella distinct ridge.

Gastronotic region ( Figures 6a and 10a ) — 15 pairs of notogastral setae, no difference to protonymph.

Ventral region of idiosoma ( Figures 6b and 10b ) — adanal setae ad 1 –ad 3 short and acuminate, flanking anal valves. Cupule iad located near anterior border of anal aperture, cupule ih close to opisthonotal gland and ips situated slightly posterior between iad and ih. Three pairs of genital setae in row on genital valves (no variation). One pair of very short aggenital setae posterior and lateral to genital opening. Formula of epimeral setation (I- IV): 3-1-2-2. Seta 4b located medially.

Legs ( Figures 7a–d ) — Setation see Table 1.

Tritonymph — Body length (N = 24): 283 – 353 µm, average 318 µm.

Gastronotic region ( Figures 8a and 10c ) — 15 pairs of notogastral setae, all the same shape as in proto- and deutonymph.

Ventral region of idiosoma ( Figures 8b and 10d ) — very short anal setae an 1 and an 2 on median margin of anal valves. Cupules same positions as in deutonymph. Five pairs of genital setae positioned in median row on genital valves (constant). Epimeral setation (I-IV): 3-1-2-3. Seta 4c located next to trochanter.

Legs ( Figures 9a–d ) — solenidia and chaetome see Table 1.

Eggs of T. sarekensis — The average number of eggs per gravid female was one, the observed maximum number was two. The size of the eggs of T. sarekensis is approximately 150 µm in length and 70 µm in diameter.

The color ranges from light brown to grey brown. The exochorion consists of flat and round coin like structures (diameter 3 – 6 µm) which are attached to the endochorion. The surface of these elevations is uneven and fibrous sticky material is dispersed between these "coins" ( Figures 11a–b).

Figures

FIGURE 2: T. sarekensis larva. a – dorsal view; b – ventral view.

FIGURE 3: T. sarekensis larva left legs. a – leg I antiaxial view; b – leg II paraxial view; c – leg III antiaxial view.

FIGURE 4: T. sarekensis protonymph. a – dorsal view; b – ventral view.

FIGURE 5: T. sarekensis protonymph legs. a – right leg I antiaxial view; b – left leg II antiaxial view; c – left leg III paraxial view; d – right leg IV antiaxial view.

FIGURE 6: T. sarekensis deutonymph. a – dorsal view; b – ventral view.

FIGURE 10: T. sarekensis LM-micrographs; scale bar = 50 µm. a – deutonymph dorsal view, layered from 15 sequentially focused images; b – deutonymph ventral view, 18 layered images; c – tritonymph dorsal view, 20 layered images; d – tritonymph ventral view, 20 layered images; arrowhead points to median divided mentotectum.

FIGURE 7: T. sarekensis deutonymph legs antiaxial view. a – right leg I; b – left leg II; c – left leg III; d – right leg IV.

FIGURE 8: T. sarekensis tritonymph. a – dorsal view; b – ventral view.

FIGURE 9: T. sarekensis tritonymph legs antiaxial view. a – left leg I; b – right leg II; c – left leg III; d – right leg IV.