ZOOLOGÍA

Notes on Prostigmata of Argentina 1: A new species of the genus Cryptognathus Kramer (Acari: Cryptognathidae)

 

Andrés O. Porta

División Aracnología, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Av. Ángel Gallardo 470 C1405DJR, Buenos Aires, Argentina. E-mail: hugporta@yahoo.com.ar

Doi: 10.22179/REVMACN.21.640

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Abstract

Cryptognathus amalfitanii sp. nov. is described and illustrated based on samples collected from epiphytes of the species Tillandsia aëranthos (Bromeliaceae) from different trees in Buenos Aires, Argentina.

Key words: Epiphytes; Mites; Prostigmata.

Resumen

Notas sobre Prostigmata de Argentina 1: Una nueva especie del género Cryptognathus Kramer (Acari:Cryptognathidae)

Se describe e ilustra Cryptognathus amalfitanii sp. nov. en base a muestras colectadas en epífitas de la especie Tillandsia aëranthos (Bromeliaceae) en varias especies de árboles en Buenos Aires, Argentina.

Palabras clave: Epífitas; Ácaros; Prostigmata.

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INTRODUCTION

The family Cryptognathidae Oudemans, 1902 comprises 60 species in three genera (Dŏgan, 2008): Favognathus Luxton, 1973 (36 species), Cryptognathus Kramer, 1873 (22 species) and Cryptofavognathus Dŏgan and Dönel, 2010 (2 species) (Fan & Zhang, 2005; Khanjani & Ueckermann, 2008; Dŏgan 2008; Dönel & Dŏgan, 2011; Uluçay & Koç, 2013). Members of this family are recognized by the presence of a protective hood anterior of the propodosoma, and extremely extendable gnathosomal base in adults (Dŏgan, 2008). Three species of this family, all belonging to the genus Favognathus, have been described from South America (Dŏgan, 2008): F. agapictus (Flechtmann, 1971) from Brazil, F. ochraceus (Summers and Chaudhri, 1965) and F. pictus (Summers and Chaudhri, 1965) both from Galapagos Islands, Ecuador. In this work we describe the first species of the family from Argentina which also constitutes the first record of the genus Cryptognathus in the Neotropical region.

MATERIALS AND METHODS

Specimens were hand collected from epiphytes of the species Tillandsia aëranthos (Bromeliaceae) on different trees in the campus of the sport club Vélez Sarsfield (Fig. 1), Ciudad Autónoma de Buenos Aires, Argentina and fixed in 96% ETOH. Mites for optical microscopy were cleared in Nesbitt’s fluid and mounted in Hoyer’s medium following Walter & Krantz (2009). Specimens were studied and measured under an Olympus BH-2 or a Leica D2500 compound microscope. Drawings were made with a camera lucida mounted on the microscope. For scanning electron microscopy (SEM), specimens were dehydrated through a series of ethanol solutions of increasing concentration in absolute hexamethyldisilazane (Porta & Tricarico 2018) and then air-dried, mounted on individual stubs using adhesive copper tape, sputter-coated with gold–palladium and examined under a FEI XL 30 TMP scanning electron microscope varying the working distance and the voltage (15-22 eV). SEM photographs were taken in two sessions in August 2017.

Fig. 1. Collecting locality with detail of the epiphyte Tillandsia aëranthos (Bromeliaceae) where the specimens Cryptognathus amalfitanii sp. nov. have been collected.

The terminology of palp and leg chaetotaxy follows that of Grandjean (1944, 1946) except for the adoption of the interpretation of Robaux (1975) for the κsetae of the genu I as one σsolenidion. Idiosomal chaetotaxy terminology follows Kethley (1990) and Fan & Zhang (2005). All measurements are given in micrometers (μm) for the holotype and paratypes (in parentheses). The material examined is deposited at the Arachnological Collection of the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires (MACN-Ar).

RESULTS

Family: Cryptognathidae Oudemans, 1902
Genus: Cryptognathus Kramer, 1879
Type species: Cryptognathus lagena Kramer, 1879

Cryptognathus amalfitanii sp. nov.
(Figs. 2-12)

Fig. 2. Cryptognathus amalfitanii sp. nov. habitus alive.

Fig. 3. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40666). Habitus dorsal. Scale bar: 100 μm.

Fig. 4. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40666). A dorsal view of the hood; B. detail of the dorsal sculpture. Scale bars: A 20 μm; B 10 μm.

Fig. 5. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40640). Habitus in antiaxial view. Scale bar: 100 μm.

Fig. 6. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40640). Ventral view. Scale bar: 100 μm.163 Porta: A new species of the genus Cryptognathus Kramer

Fig. 7. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40640). Ventral view, A. Detail of the porous sector posterior to coxae IV; B. central striated sector anterior to genital valves; C. detail of the same; D. genital valves. Scale bars: A; B; D20 μm; C5 μm.

Fig. 8. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40689). A paraxial view of the palp; paratype (MACN-Ar 40663), B. dorsal view of the palp; paratype (MACN-Ar 40665), C. ventral view of the male genitalia; D. chelicera, antiaxial view. Abbreviations: cf: cuticular frame, cl: tibial claw, d: duct, gl: genital gland, pe: peritreme. Scale bars: A-D: 50 μm.

Fig. 9. Cryptognathus amalfitanii sp. nov. paratype (MACN-Ar 40666). A. antiaxial view of the left palp; paratype (MACN-Ar 40640), B. dorsal view of the left palp tibia; C. detail of the distal portion of the tarsus of the left palp; paratype (MACN-Ar 40666), D: hypostome. Scale bars: A; D 20 μm; B 10 μm; C 5 μm.

Fig. 10. Cryptognathus amalfitanii sp. nov. A-D, holotype (MACN-Ar 40686). Dorsal view of the left legs I-IV. Scale bars: A-D 50 μm.

Fig. 11. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40666). Leg I: A. antiaxial view of the right tarsus; B. paraxial view of the right tarsus; C. detail of the tarsus solenidium; D. right tibia I, dorsal view; E same, detail of the solenidia; F paraxial view of the left genu. Scale bars: A; B; D 20 μm; C 5 μm; E 2 μm; F 10 μm.

Fig. 12. Cryptognathus amalfitanii sp. nov., paratype (MACN-Ar 40666): A. dorsal view of the left tibia and tarsus II; B. antiaxial view of the left tarsus II; C. dorsal view of the left tibia and tarsus III; D, F, antiaxial view of the left tarsus IV; E left tibia III, antiaxial view. Scale bars: A; B; C; D 20 μm; E; F 10 μm.

Etymology. The specific name is a patronymic in memory of José Luis “Don Pepe” Amalfitani (1894-1969) for his invaluable contribution to the developing of Club Atlético Vélez Sarsfield as a great social and sportive institution.

Diagnosis
Palptibial claw present (Figs. 8A-B, 9B), front margin of the hood smooth (Fig. 4A), dorsal shield entirely reticulated (Fig. 3) with irregular polygons, each with more than 10 pores uniformly distributed (Fig. 4B); ventral shield (Fig. 6) without reticulations, with an Ushaped sector of pores behind setae 3a which extends laterally behind coxae IV and reaches ag1 but not the anterior ring of genital valves and with lateral patches of pores between coxae III and IV, behind coxae I, II and hypostosomal ring; with a central ventral region between setae 4a and ag1 with longitudinal striae (Fig. 7C) that becomes transversally oriented (Fig. 7B) before the genital plates (Fig. 3); solenidia ωof tarsi III and IV absent in females and present in males; tarsi III and IV with only one proximoventral seta (Figs. 10C-D, 12C-D), solenidion present on tibia III (Figs. 10C, 12C, E ) and absent on tibia IV (Fig. 10D); (tc) setae on tarsus II dissimilar, tc’ eupathidical and tc” not (Fig. 12B).

Comparisons
According to the key for the genus by Uluçay & Koç 2013, C. amalfitanii n. sp. resembles C. striatus Luxton, 1973 and C. vulgaris Luxton, 1973 by the reticulated dorsal shield, ventral shield without reticulations and front margin of hood smooth. It differs from C. striatus by the presence of both pores behind coxae IV and reticulation covering entire dorsal shield. From C. vulgaris by the absence of solenidia on female tarsus III and IV and by the presence of punctuation covering all dorsal shield.

Type material
Holotype, female (MACN-Ar 40686), hand collected from epiphytes of the species Tillandsia aëranthos (Bromeliaceae) on various trees, both exotic (Pinus sp., Populus sp.), and native (Schinus molle), in the campus of the sport club Vélez Sarsfield in Ciudad Autónoma de Buenos Aires (34° 38.023’S , 58° 30.963’Oand altitude 10 m a.s.l), 16.VII.2017, A. O. Porta leg. Paratypes, same data, 6 females (MACN-Ar 40652, MACN-Ar 40670, MACN-Ar 40663, MACN-Ar 40644, MACN-Ar 40689, MACN-Ar 40666), 3 males (MACN-Ar 40649, MACN-Ar 40656, MACN-Ar 40691, MACN-Ar 40665), 2 inmatures (MACN-Ar 40645, MACN-Ar 40669) all mounted in slides and 2 females (MACN-Ar 40666, MACN-Ar 40640) mounted for MEB.

Description
Colour chilli red in live (Fig. 2).
Female (n= 7)
Gnathosoma (Figs. 8 A-B, D, 9)
Chelicerae slender (Fig. 8D) 100 (98–108); movable digits 28 (24-28). Peritremes (pe.) ramifying just back digits articulation. Palp segments trochanter glabrous; femur with 3 setae (Fig. 8A, B), 36 (30-38) long; genu with 2 setae, 30 (26-30) long; tibia with 3 setae, 16 (14-18) long, palptibial claw present (Figs. 8A, B, 9B); tarsus 8 (8-10), with 7 setae and one solenidion, (ul), acm and sul eupathidical (Fig. 9C). Subcapitular setae m 26 (25-31), m-m 16; or1 10 or2 10.
Idiosoma (Figs. 2, 3) Oval in shape, 315 (245–315) long, 162 (153–186) wide al level of coxae IV. Anterior margin of the hood smooth (Fig. 4A) with 5-6 dimples in each longitudinal row. Dorsal shield (Fig. 3) completely ornamented with reticulations except region beside setae h1, reticular cells with more than 10 pores (Fig. 4B), pores distributed evenly in all reticulation cells; one pair of eyes and one pair of postocular bodies (pob) laterally between setae sci and sce. Eyes 6.4 (5-10) in diameter; pob 8.8 (8-11.2) in diameter. Dorsal shield with three pairs of slit-like cupules as follows: ia posterior to c1 (Figs. 3, 5), im posterior to setae e1 and anterior to e2 (Figs. 3, 5) and ip posterior to f1 and anterior to h1 (Fig. 3); polygonal cells (Fig. 4B) mostly longer than wide. Dorsal idiosomal setae smooth. Length of dorsal setae: vi: 12 (8-13); ve: 12 (7-13); sci: 12 (10-12); c1: 16 (11-17); sce: 15 (15-18); d1: 17 (13-17); e1: 16 (15-16); e2: 16 (13-18); f1: 12 (12-13); h1: 12 (10-13); h2: 15 (12-16). Distance between dorsal setae: vi-vi: 24 (24-30); vi-ve: 14 (10-19); ve-ve: 30 (26-30); ve-sci: 6 (4-10); sci-sci: 46 (28-46); c1-c1: 52 (45-53); sce-sce: 84 (80-102); c1-sce: 28 (30-32); d1-d1: 84 (64-84); d1-e1: 47 (45- 48); e1-e1: 70 (68-76); e1-e2: 26 (21-27); e2-e2: 100 (102-106); e1-f1: 48 (45-52); f1-f1: 48 (39-44); f1-h1: 36 (34-42); h1-h1: 20 (20-26); h1-h2: 27 (22-32); h2-h2: 78 (72-82).
Ventral shield (Fig. 6), without reticulations, with an Ushaped sector of pores behind setae 3a which extends laterally behind coxae IV and reaches ag1 but not the anterior ring of genital valves, and with lateral patches of pores between coxae III and IV, behind coxae I, II and hypostosomal ring; with a central ventral region between setae 4a and ag1 with longitudinal striae (Fig. 7C) that become transversally oriented (Fig. 7B) before the genital plates (Fig. 3). Ventral setae subequal, 1a:17 (20-24); 3a:14 (11-18); 4a: (14-17); 1a-1a:18 (17-20); 3a-3a: 37(33-39); 4a-4a: 60 (56-68). Aggenital setae ag1: 12 (11-17); ag2: 12 (8-12); ag3: 9 (8-9); ag1-ag1: 48 (44-49); ag2-ag2: 53 (52-54); ag3-ag3: (36-40). Genital setae g1:12 (8-12); g2:10 (7-12); g3:10 (8-13). Pseudoanal setae ps1:10 (6-12), ps2:10 (9-10), ps3:11 (8-10).
Legs (Figs. 10, 11, 12) For measurements see table 1. Segments of legs with striae. Solenidion ωabsent on tarsi III and IV (Figs. 10C, D, 12D, C); ϕon tibiae IV absent (10D); Iϕ” at same level as Iϕ’ (Figs. 10A, 11D-E), more than 2x longer than ϕ’; IIϕon basal half of tibia II (Figs. 10B, 12A); IIIϕon basal half of tibia III (Figs. 10C, 12C, E). Counts of setae and solenidia on legs I–IV: coxae (excluding 1a, 3a, and 4a) 2 +1elcp, 1, 2, 1; trochanters 1, 1, 2, 1; femora 3, 3, 2, 2; genua 5 + 1σ, 4 + 1σ, 2, 3; tibiae 5 + 2ϕ, 5 + 1ϕ, 3 + 1ϕ, 3; tarsi 15 + 1ω, 12 + 1ω, 9, 9. Lengths of solenidia: Iσ: 3 (3-4), IIσ: 4 (3-4), Iϕ’: 5 (4-6), Iϕ”:12 (11-12), IIϕ: 6 (6), IIIϕ: 6 (6-7), Iω: 10 (10-12), IIω: 7 (6-8)

Table 1: length of the leg segments of the female. Abbreviations: Tr.: trochanter, Fe.: femur, Ge.: genu, Ti.: tibia, Ta.: tarsus.

Male (n= 3)
Similar to female but with enlarged solenidiaω present in all legs and with genital and anal openings fused.
Gnathosoma
Chelicerae 80; movable digits 24-24. Palpal setae as in female; femur 28-34 long; genu 22-24 long; tibia 12-14 long, palptibial claw present; tarsus 8. Subcapitular setae m: 22-36, m-m: 6-12, or1: 8, or2: 8.
Idiosoma
Oval, 224–240 long, 120–144 wide al level of coxae IV, hook 44-48 long with 4-5 dimples in each longitudinal row. Dorsal and ventral shields similar to female, but with setae h2 more advanced and more proximal to f1 than to h1; genital and anal openings fused and genital setae absent. Internal genitalia (Fig. 8C) with a cuticular frame (cf) connected by a long duct (d) with a large impair gland (gl). Eyes 4.8-6.4 in diameter; pob 8.8-16 in diameter. Length of dorsal setae: vi: 8-10; ve: 8-12; sci: 8-10; c1: 12-13.6; sce: 12-14; d1: 16; e1: 10-16; e2: 12-14; f1: 9-10; h1: 10- 11; h2:10. Distance between dorsal setae: vi-vi: 21-24; vi-ve: 12-13; ve-ve: 24; ve-sci: 4-6; sci-sci: 36; c1-c1: 39-45; sce-sce: 80; c1-sce: 20-24; d1-d1: 64-66; d1-e1: 40-42; e1-e1: 46-48; e1-e2: 18-22; e2-e2: 76-80; e1-f1: 35-38; f1-f1:24; f1-h1: 13-14; h1-h1: 14-17; f1-h2: 9; h1-h2:12; h2-h2:16. Ventral setae, 1a: 12-16; 3a:15-18; 4a: 12-14; 1a-1a:14-15; 3a-3a: 30-32; 4a-4a: 44-48. Aggenital setae ag1: 10-12; ag2: 12; ag1-ag1: 42-44; ag2-ag2: 20. Pseudoanal setae ps1: 9-10; ps2: 8; ps3: 7.
Legs For measurements see table 2. Counts of setae and solenidia on legs I–IV as in female, except for the presence of enlarged solenidia on tarsus III and IV. Lengths of solenidia: Iσ: 4, IIσ: 3, Iϕ’: 5, Iϕ”: 11, IIϕ: 6, IIIϕ: 6, Iω: 14-15, IIω: 11-16, IIIω: 14-16, IVω: 14-16.

Table 2: length of the leg segments of the male.

Deutonymph (n=2)
Gnathosoma
Chelicerae 72–79; movable digits 28. Palpal setae as in adults; femur 29-32; genu 24-27 long; tibia 17-22 long, palptibial claw present; tarsus 8 long. Subcapitular setae m: 20-24, m–m: 12-20; or1: 8, or2: 8.

Idiosoma
Idiosoma 259–289 long, 146-154 wide al level of coxae IV, prodorsal projection small, not hood-like; dorsal shield smooth, without the reticulations or pores presents in the adults; ventral shield finally striated; without genital valves or setae. Eyes 5-7 in diameter; pob 8-12 in diameter. Length of dorsal setae: vi: 7-13; ve: 13-16; sci: 16; c1: 16; sce: 13-20; d1: 16; e1: 13-18; e2: 14-19; f1: 12-17; h1: 14; h2: 16. Distance between dorsal setae: vi-vi: 18-19; vi-ve: 9; ve-ve: 30; ve-sci: 10; sci-sci: 30-46; c1-c1: 53-55; sce-sce: 102 ; c1-sce: 20-26; d1-d1: 64-76; d1-e1: 48-52; e1-e1: 40-46; e1-e2: 14-22; e2-e2: 70-76; e1-f1: 46-48; f1-f1: 50-55; f1-h1: 34-40; h1-h1: 13-16; h1-h2: 28-33; h2-h2: 70-75.
Legs For measurements see table 3. Counts of setae and solenidia on legs I–IV as in female. Lengths of solenidia: Iσ: 3-4, IIσ: 3-4, Iϕ’: 4, Iϕ”: 10, IIϕ: 4-5, IIIϕ: 4, Iω: 10-11, IIω: 7-8.
Remarks: The absence of solenidia on tarsus III and IV in immatures and females could indicate that it is the plesiomorphic condition for the genus.

Table 3: length of the segments of the legs of the deutonymph.

ACKNOWLEDGEMENTS

Drs. Alireza Saboori (University of Tehran, Iran), Pablo A. Martinez (University of Mar del Plata, Argentina) and Andrés Ojanguren (Museo Argentino de Ciencias Naturales) made very valuable comments on the preliminary versions of the manuscript.

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Recibido: 12-V-2019
Aceptado: 26-X-2019