Selenoribatidae Schuster, 1963

Resch, Bettina, Baumann, Julia & Pfingstl, Tobias, 2019, The intertidal genus Indopacifica (Acari, Oribatida, Selenoribatidae): new species juvenile morphology and distribution, Zootaxa 4647 (1), pp. 322-335 : 324-334

Family Selenoribatidae Schuster, 1963

Genus Indopacifica Pfingstl, Shimano & Lienhard 2019

Indopacifica iohanna sp. n. Resch & Pfingstl

Type material. Holotype: adult female, Philippines, Maribago, 1980, coll. V. Storch; preserved in ethanol, deposited in PNM (Zoology Division) . Two paratypes (2 adult males) from the same sample are deposited in SMNG and additional paratypes are in IBUG.

Etymology. The specific epithet is the latinized name Johanna given as a noun in apposition; the species is dedicated to the daughter of Bettina Resch, who was pregnant with her when she performed her studies on this species as part of her Master’s degree program.

Diagnosis. Slender gastronotic region; median longitudinal, hourglass-shaped depression on epimeron I; two pairs of adanal setae; proximoventral tooth on claws absent.

Indopacifica iohanna can be distinguished from all known congeners by the lack of a proximoventral tooth on each claw.

Description of adult. Measurements. Females (n = 28), length: 274–295 µm (mean 285 µm), width: 151–169 µm (mean 160 µm); males (n = 24), length: 250–280 µm (mean 263 µm), width: 140–167 µm (mean 155 µm).

Integument. Colour brown. Cerotegument of prodorsum, ventral region and legs granular. Notogastral cerotegument strongly granular with large granules irregularly surrounded by smaller granules.

Prodorsum ( Figure 1A ). Rostrum slightly rounded in dorsal view. Rostral (ro) and lamellar setae (le) simple and short. Interlamellar seta (in) thin, very short, exobothridial seta (ex) minute. Bothridium large cup with lateral incision.

Gnathosoma. Chelicera chelate, with two teeth on each digit ( Figure 2A ). Setae cha and chb of approximately same length, both dorsally slightly pectinate. Palp setal formula 0-2-1-3-8 (+ solenidion ω) ( Figure 2B ). Femur with paraxial porose area. Distal part of rutellum developed as thin, triangular, slightly inwardly curved membrane with longitudinal incision. Setae a and m long, smooth. Mentum regular, finely granular, seta h simple, long.

Notogastral region ( Figure 1A ). Notogaster slender and oval in dorsal view. A pair of elliptic and slightly oblique depressions between lyrifissure ia and setae of c -row. Fourteen pairs of thin, setiform notogastral setae (length 10–15µm), c 1, c 2, da, dm, dp, la, lm, lp, h 1-3, p 1-3; c 3 absent. Orifice of opisthonotal gland gla next to seta la. Lyrifissure im between setae la and lm.

Lateral aspect ( Figure 1C ). Pedotectum I present, round, small. Lateral enantiophysis consisting of two opposite but slightly overlapping projections S 1 and S 2; former rounded, latter pointed. Discidium di developed as prominent conical bulge.

Podosoma and venter ( Figure 1B ). Median longitudinal, hourglass-shaped depression on epimeron I covered with fine granules and inconspicuous semicircular depression on posterior border of epimeron III. Three pairs of short, fine genital setae. Preanal organ triangular in ventral view, interior part anchor-shaped. Two pairs of simple adanal setae ad 1-2. Lyrifissure iad slightly oblique, next to anterior border of anal orifice.

Legs ( Figure 3 ). Monodactylous. Long hook-like claws without ventral tooth. Cerotegument granular. No porose areas detectable. Setation and solenidia: Leg I (0- 3-2-3-18) (1-2-2), leg II (0- 3-2-3-15) (1-1-1), leg III (1-2-1- 2-13) (1-1-0), leg IV (1-2-1-3-12) (0-1-0) (for details see Table 2 ).

Common features of juvenile stages. Colour brown. Integument plicate and soft, except for centrodorsal plate. Prodorsum triangular, anterior part finely granular, rostrum rounded. Rostral (ro), lamellar seta (le) and interlamellar seta (in) short, exobothridial seta (ex) vestigial, shaped like minute lamella. Sensillus clavate, distally spinose. Bothridium cup-like, laterally opened. Gnathosoma similar to that of adult stage. Cerotegument of venter finely granular, larger granules near leg insertions and ventral furrows. Ventral furrows typical for selenoribatid juveniles. In nymphal stages no distinct genital sclerites developed, genital opening thin longitudinal slit. Orifice of opisthonotal glands (gla) and cupules (ia, im, ih, ip, ips, iad) not detected in any stage (but absence not confirmed).

Larva. Length (N=4) 155–167 μm (mean 160 μm).

Gastronotic region ( Figures 4A and 4C ). Eleven pairs of notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-2; h 3 absent; h 2 longer than others. Weak transverse ridge on centrodorsal plate, just posterior to level of setae dm and lm.

Ventral region of idiosoma ( Figure 4B ). Epimeral setation 1-0-1, epimeral seta 1a conspicuously longer than 3a. Claparède’s organ cla globular.

Legs. Setation and solenidia ( Table 2 ): Leg I (0- 3-2-3-16) (1-1-1), leg II (0- 3-2-2-13) (1-1-1), leg III (0- 2-1-1- 13) (1-1-0).

Protonymph. Length (N=4): 175–203 μm (mean 189 μm).

Gastronotic region. Fifteen pairs of notogastral setae; c 1-3, da, dm, dp, la, lm, lp, h 1-3 and p 1-3, all approximately same length.

Ventral region of idiosoma. Epimeral setation 1-0-1-1. Seta 4a medially on epimeron IV. One pair of short genital setae. Aggenital setae absent.

Legs. Setation and solenidia ( Table 2 ): Leg I (0- 3-2-3-16) (1-1-2), leg II (0- 3-2-2-13) (1-1-1), leg III (0- 2-1-1- 13) (1-1-0), leg IV (0-0-0-0-7) (0-0-0).

Deutonymph. Length (N=9): 212–240 μm (mean 227 μm).

Gastronotic region. Fifteen pairs of notogastral setae, same positions and shapes as in protonymph.

Ventral region of idiosoma. Epimeral setation 1-0-1-1. Two pairs of short genital setae arranged in a longitudinal row. Two pairs of adanal setae ad 1-2 flanking anal valves.

Legs. Setation and solenidia ( Table 2 ): Leg I (0- 3-2-3-16) (1-2-2), leg II (0- 3-2-2-13) (1-1-1), leg III (0- 2-1-1- 13) (1-1-0), leg IV (0- 2-1-2-12) (0-1-0).

Tritonymph. Length (N=14): 252–283 μm (mean 266 μm).

Gastronotic region ( Figures 5A and 5C ). No difference to deutonymph.

Ventral region of idiosoma ( Figure 5B ). Epimeral setation 1-0-1-1.

Three pairs of short genital setae in longitudinal row. Two pairs of adanal setae ad 1-2 and two pairs of anal setae an 1-2.

Legs. Setation and solenidia ( Table 2 ): Leg I (0- 3-2-3-18) (1-2-2), leg II (0- 3-2-3-15) (1-1-1), leg III (0- 2-1-1- 13), leg IV (0- 2-1-2-12) (0-1-0).

Indopacifica mauritiana sp. n. Baumann & Pfingstl

Type material. Holotype: adult female, Mauritius, Islote Sancho , 09 Apr. 2018; coll. J. Baumann & F. Ferragut, preserved in ethanol, deposited in MNHM . Two paratypes (1 female and 1 male) from the same sample are deposited in SMNG and additional paratypes are stored in IBUG.

Etymology. This species is named after its type locality, Mauritius.

Diagnosis. Gastronotic region pear-shaped; rostral setae strongly inclined nearly lying on rostrum, lamellar setae vestigial; median circular depression on epimeron I; two pairs of adanal setae; proximoventral tooth on claws present.

Indopacifica mauritiana differs from all congeners in having only vestigial lamellar setae and small rostral setae that fit to the rostrum, combined with a small circular depression in the middle of epimeron I.

Description of adult. Measurements. Females (n = 8), length: 272–292 µm (mean 286 µm), width: 166–182 µm (mean 175 µm); males (n = 12), length: 271–286 µm (mean 277 µm), width: 163–181 µm (mean 170 µm).

Integument. Colour brown. Cerotegument of all body parts with densely distributed large granules, notogastral cerotegument consisting of larger granules irregularly surrounded by smaller granules.

Prodorsum ( Figure 6A ). Rostrum rounded in dorsal view, slightly projecting anteroventrally in lateral view. Rostral seta (ro) very short, strongly inclined, nearly lying on rostrum ( Figure 6B ) and hence not visible in dorsal view. Lamellar seta (le) vestigial. Interlamellar seta (in) blunt and short, exobothridial seta (ex) short. Bothridium large cup with lateral incision.

Gnathosoma. Chelicera chelate, with two teeth on each digit. Setae cha and chb of approximately same length, both dorsally slightly pectinate. Palp setal formula 0-2-1-3-8 (+ solenidion ω). Femur with paraxial porose area. Distal part of rutellum developed as thin, triangular, slightly inwardly curved membrane with longitudinal incision. Setae a and m long, smooth. Mentum regular, finely granular, seta h simple, long.

Notogastral region ( Figure 6A ). Notogaster pear shaped in dorsal view. Anterior part of notogaster with weak transversal depression, best seen in lateral view. Fourteen pairs of thin, simple notogastral setae (length 10–13µm), c 1, c 2, da, dm, dp, la, lm, lp, h 1-3, p 1-3; c 3 absent. Orifice of opisthonotal gland gla lateral, between setae c 2 and la. Lyrifissure ia oblique in humeral area, lyrifissure im between setae la and lm.

Lateral aspect ( Figure 6C ). Cerotegument granular, larger granules on pedotectum I, discidium di and in acetabular regions. Pedotectum I present, round, small. Lateral enantiophysis consisting of two opposing rounded projections S 1 and S 2. Discidium di developed as prominent conical bulge.

Podosoma and venter ( Figure 6B ). Small median circular depression on epimeron I and inconspicuous semicircular depression on posterior border of epimeron III. Three pairs of short, fine genital setae. Preanal organ triangular in ventral view, interior part anchor-shaped. Two pairs of short anal setae an 1-2 and two pairs of short adanal setae ad 1-2. Lyrifissure iad oblique, next to anterior border of anal orifice.

Legs ( Figure 7 ). Monodactylous. Long hook-like claws with one small proximoventral tooth. Femora with ventral carina. No porose areas detectable. Dorsal seta d on all femora slightly barbed. Famulus ε on tarsus I short, broad, conical rod. Setation and solenidia: Leg I (0- 3-2-3-18) (1-2-2), leg II (0- 3-2-3-15) (1-1-1), leg III (1-2-1-2- 13) (1-1-0), leg IV (1-2-1-3-12) (0-1-0).

Figures

FIGURE 1. Indopacifica iohanna sp. n. adult female. A—dorsal view, legs omitted; B—ventral view, distal segments of legs omitted, subcapitulum only partly shown; C—lateral view, legs and entire gnathosoma omitted.

FIGURE 2. Indopacifica iohanna sp. n. adult mouthparts. A—right chelicera, antiaxial view; B—right pedipalp, antiaxial view.

FIGURE 3. Indopacifica iohanna sp. n. adult legs, antiaxial view. A—right leg I; B—right leg II; C—left leg III; D—left leg IV.

FIGURE 4. Indopacifica iohanna sp. n. larva. A—dorsal view; B—ventral view; C—lateral view.

FIGURE 5. Indopacifica iohanna sp. n. tritonymph. A—dorsal view; B—ventral view; C—lateral view.

FIGURE 6. Indopacifica mauritiana sp. n. adult male. A—dorsal view, legs omitted; B—ventral view, distal segments of legs omitted, subcapitulum only partly shown; C—lateral view.

FIGURE 7. Indopacifica mauritiana sp. n. adult left legs, antiaxial view. A—leg I; B—leg II; C—leg III; D—leg IV.

Tables

TABLE 2. Indopacifica iohanna sp. n., chaetome and solenidia from larva to adult. First development of setae characterized by letters. () = pairs of setae,-= no change with regard to preceding stage.

	Instars	Trochanter	Femur	Genu	Tibia	Tarsus
Leg I	larva	-	d, bv´´, l´	(l), σ	(l), v´, ϕ 1	(pl), (pv), s, (a), (u), (p), (tc), (ft), ε, ω 1
	protonymph	-	-	-	-	ω 2
	deutonymph	-	-	-	ϕ 2	-
	tritonymph	-	-	-	-	(it)
	adult	-	-	-	-	-
Leg II	larva	-	d, bv´´, l´	(l), σ	l´, v´, ϕ	(pv), s, (a), (u), (p), (tc), (ft), ω
	protonymph	-	-	-	-	-
	deutonymph	-	-	-	-	-
	tritonymph	-	-	-	l´´	(it)
	adult	-	-	-	-	-
Leg III	larva	-	d, ev´	l´, σ	v´´, ϕ	(pv), s, (a), (u), (p), (tc), (ft)
	protonymph	-	-	-	-	-
	deutonymph	-	-	-	-	-
	tritonymph	-	-	-	-	-
	adult	v´	-	-	l´	-
Leg IV	protonymph	-	-	-	-	(pv), (u), (p), ft´´
	deutonymph	-	d, ev´	d	l´, v´, ϕ	s, (a), (tc)
	tritonymph	-	-	-	-	-
	adult	v´	-	-	l´´	-