Review of the genus Ceratotarsonemus De Leon, 1956 (Acari: Prostigmata: Tarsonemidae), with description of a new species from the Amazon Forest Author Rezende, José Marcos Author Lofego, Antonio Carlos Author Gulbronson, Connor Author Bauchan, Gary Author Ochoa, Ronald text Zootaxa 2018 2018-09-21 4483 2 271 294 journal article 29510 10.11646/zootaxa.4483.2.3 978177a0-69ca-4f91-88ad-fe44cb660e9b 1175-5326 1437673 B013B1B6-D013-4A1F-9436-7D3FE40AC044 Ceratotarsonemus amazonicus Rezende, Lofego & Ochoa sp. nov. ( Figs. 4–16 ) Diagnosis. Female: Pharyngeal pump about 1/2 gnathosomal width. Palpal length about 1/2 gnathosomal length. Prodorsal shield with hexagonal reticulation posteriorly. Tergite C with inverted U-shaped reticulation dorsally, which has four rows of reticula. All dorsal setae coarsely barbed, except for bothridial setae sc1 . Vertical setae v1 about ½ length scapular setae sc2 on prodorsum. Setae c1 distinctly longer than c2 on tergite C. Setae c2 and e long (~ 65 and 80 µm, respectively). Ventral surface of propodosoma with prosternal apodeme complete, extending from apodemes 1 to sejugal apodeme. FIGURE 4. Ceratotarsonemus amazonicus , sp. nov. : A–D: different focal planes (from dorsal to ventral view) of the gnathosoma under the differential interference contrast (DIC) microscopy (squared areas in A–B: dorsal apices of cheliceral levers). Description. Female: holotype and four paratypes measured. Gnathosoma ( Figs. 4 and 5 A-B): capsule subquadrate in outline, 28 (22–28) long (~ 0.2x LI), 19 (18–21) wide (~ 0.2x WI). Palpi 11 (11–13) long (~ 0.4x LG), 3 wide (~ 0.2x WG), with small rounded processes apically, two minute setae. Pharynx fusiform, 15 (13–15) long (~ 0.5x LGC), 6 wide (6–7) (~ 0.3x WG), with external walls and musculature well developed. Cheliceral stylets short, subtriangular, attached to defined basal levers. Gnathosomal setae: dgs 10 (10–12) long (~ 0.4x LG), setiform, smooth. Setae vgs 7 (5–7) long (~ 0.3x LG), setiform, smooth. Setae pp absent. Relative length of gnathosomal setae ( dgs : vgs ): 1: 0.7. Idiosoma, dorsal plates and stigmata ( Figs. 5C and 6–9 ): idiosoma 172 (159–172) long (~ 1.9x WI), 95 (95–103) wide at level of c2 (0.6x LI). PrS 54 (48–56) long (~ 0.3x LI), 62 (60–65) wide (~ 0.6x WI) at stigmata level, hoodlike, covering gnathosoma, with convex posterior margin, reticulated. Prodorsomedial apodeme absent. Stigmata openings located closely anterior to scapular setae sc1 , on inconspicuous projections anterolaterally. Tracheal tubes hardly discernible. Postatrial sacs absent or not visible. Tergite C 44 (40–48) long (~ 0.3x LI), 95 (95–103) wide at level of c2 , with concave posterior edge, reticulated, covered by roulade-shaped cerotegument. D 65 (62–68) long (~ 0.4x LI), 75 (73–78) wide at level of d (~ 0.8x WI), with distinctly convex posterior margin. EF 20 (18–20) long (~ 0.1x LI), 50 (48–50) wide at level of e (~ 0.5x WI), with slightly convex posterior edge. H 10 long (~ 0.07x LI), 25 (23–25) wide at level of h (~ 0.2x WI), with convex margin. PrS and C covered medially with reticulate turtle-shell-like ornamentation. Dorsal setae, pits and cupules ( Figs. 5D , 6 , 7 and 10 ) : All dorsal setae coarsely barbed, except for bothridial setae sc1. v1 72 (64–72) (~ 3.5x DBB v1 ); sensilli sc1 16 (13–16) (~ 0.5x DBB sc1 ), capitate with tiny spines; sc2 102 (94–102) (~ 2x DBB sc2 ), inserted anterolaterally to sc1 ; c1 85 (80–85) (~ 1.4x DBB c1 ), inserted closely to margin of tergite D; c2 64 (64–70) (~ 1x DBB c2 ); d 106 (105–110) (~ 2.5x DBB d ); e 74 (74–86) (~ 2.5x DBB e ); f 31 (29–34) (~ 3x DBB f ); h 24 (23–26) (~ 1.2x DBB h ). Relative length of dorsal setae (mean values— v1 : sc1 : sc2 : c1 : c2 : d : e : f : h ): 1: 0.2: 1.4: 1.2: 0.9: 1.5: 1: 0.5: 0.4. Distance between dorsal setae: v1–v1 20 (20–21); sc1– sc1 30 (29–30); sc2–sc2 50 (50–52); v1 –sc2 22 (20–22); c1–c1 60 ; c2–c2 65 (62–65); c1–c2 18 (16–19); d–d 40 (38–42); e–e 30 (28–32); f–f 10 (10–12); e–f 13 (12–14); h–h 20 (18–20). Relative distances between setae bases (mean values— v1–v1 : sc1–sc1 : sc2–sc2 : v1 –sc2 : c1–c1 : c2–c2 : c1–c2 : d–d : e–e : f–f : e–f : h–h ): 1: 1.5: 2.5: 1.1: 3: 3.4: 0.9: 2: 1.5: 0.5: 0.6: 1. Pits v2 located nearly in oblique line between setae sc2 and v1 on either side, nearly anteriad of sc1 . Diameter and position of cupules: ia 4 anterolaterally to setae d ; im 3 anterolaterally to setae e ; ih difficult to discern. FIGURE 5. Ceratotarsonemus amazonicus , sp. nov. : Gnathosoma: A—ventral view; B—detail of the palps and tips of chelicerae (squared). Stigmata: C—lateral view (squared); D—ventral view, showing also the bothridial setae sc1 . Ventral plates ( Figs. 11–14 ): PrP 40 (38–41) long (~ 0.25x LI), 72 (70–72) wide at level of sejugal apodeme (~ 0.8x WI), anterior edge between apodemes 1 distinctly concave, lateral ridges between trochanters I and II convex. MtP 47 (46–47) long (~ 0.4x LI), 90 wide at level of setae 3a (~ 1x WI), anterior margin nearly straight, posterior margin undulate between trochanters III and IV. Lateral extensions of metapodosomal ventral plate extend over tergites D and EF laterally. Tegula 3 long (~ 0.02x LI), 18 (16–18) wide (~ 0.2x WI), margin convex. Ag 40 (38–40) long (~ 0.25x LI), without setae. Ps 9 long (~ 0.6x LI), 16 wide at level of setae ps (~ 0.2x WI), posterior margin slightly concave. Ventral extensions of coxisternal plates IV slightly overlapped medially behind tegula. Ventral setae and coxal pits ( Fig. 11 ): setae 1a 8 (7–8) (~ 0.8x DBB 1a ), setiform, smooth, near posteromedial margin of apodemes 1; 2a 8 (8–10) (~ 0.3x DBB 2a ), setiform, smooth, near posteromedial margin of apodemes 2; 3a 7 (6–7) (~ 0.5x DBB 3a ), setiform, smooth, near bifurcation of poststernal apodeme; 3b 8 (7–9) (~ 0.3x DBB 3b ), setiform, near posterior margin of apodemes 4; ps 14 (12–14) (~ 0.9x DBB ps ), setiform, serrate. Relative length of ventral setae ( 1a : 2a : 3a : 3b : ps ): 1: 1.0: 0.9: 1.0: 1.9. Distance between ventral setae: 1a–1a 10 (9–10); 2a–2a 23 (22–24); 3a–3a 13 (13–14); 3b–3b 25 (24–26); ps–ps 16 (16–17). Relative distance of ventral setae bases (mean values— 1a–1a : 2a–2a : 3a–3a : 3b–3b : ps–ps ): 1: 2.3: 1.3: 2.5: 1.6. Coxal pits: 1b located well laterad of setae 1a ; 2b located well laterad of setae 2a . FIGURE 6. Ceratotarsonemus amazonicus , sp. nov. : dorsal surface. FIGURE 7. Ceratotarsonemus amazonicus , sp. nov. : dorsal surface: A—phase contrast; B—differential interference contrast; C—low temperature scanning electron microscopy. FIGURE 8. Ceratotarsonemus amazonicus , sp. nov. : ornamentation on dorsal surface: A—differential interference contrast; B—low temperature scanning electron microscopy. FIGURE 9. Ceratotarsonemus amazonicus , sp. nov. : details of wax-like substance over the dorsum under low temperature scanning electron microscopy (LT-SEM). Ventral apodemes ( Figs. 11–14 ): Apodemes 1 well defined, joined with anterior end of prosternal apodeme. Apodemes 2 not joined to prosternal apodeme. Prosternal apodeme well defined, extending from junction with apodeme 1 to sejugal apodeme. Sejugal apodeme well defined, uninterrupted. Apodemes 3 extending diagonally from proximity of base of seta 3a to (but not laterally beyond) anterior margin of trochanters III, with a median bent. Apodemes 4 extending diagonally, from posterior third of poststernal apodeme nearly to base of seta 3b . Poststernal apodeme bifurcated anteriorly. Legs ( Figs. 15–16 ): length (measured from trochanter to tarsus): leg I 45 (45–49) (~ 0.3x LI); leg II 49 (43–49) (~ 0.3x LI); leg III 86 (80–86) (~ 0.5x LI); leg IV 28 (27–28) (~ 0.2x LI). Relative lengths of legs (mean values— I:II:III:IV): 1: 1.0: 2.0: 0.5. Free leg segments: leg I: femur I 14 (13–14) long (~ 0.3x LLI), 10 (9–10) wide (~ 0.6x LFeI); genu I 8 (8–9) long (~ 0.2x LLI), 8 (7–8) wide (~ 1.0 x LGeI); tibiotarsus I 15 (15–17) long (~ 0.3x LLI), 5 wide (0.3x LTbTaI). Leg II: femur II 12 (12–14) long (~ 0.25x LLII), 11 (11–13) wide (~ 1.0x LFeII), with a small concavity; genu II 7 (7–8) long (~ 0.2x LLII), 8 (8–9) wide (~ 1.1x LGeII); tibia II 7 (7–8) long (~ 0.2x LLII), 6 (6– 7) wide (~ 1.0x LTbII); tarsus II 7 long (~ 0.2x LLII), 5 (5–6) wide (~ 0.8x LTaII). Leg III: femorogenu III 16 (16– 18) long (~ 0.2x LLIII), 6 (6–8) wide (~ 0.4x LFeGeIII); tibia III 17 (16–18) long (~ 0.2x LLIII), 6 (6–7) wide (~ 0.3x LTbIII); tarsus III 10 (10–12) long (~ 0.1x LLIII), 4 (4–6) wide (~ 0.4x LTaIII). Leg IV: femorogenu IV 15 (15–16) long (~ 0.5x LLIV), 3 wide (~ 0.2x LFeGeIV); tibiotarsus IV 8 (8–9) long (~ 0.3x LLIV), 3 wide (~ 0.3x LTbTaIV). Trochanters IV separated by interval of ~ 3x their widths. Ambulacra of legs I-III: ambulacrum I with minute empodial pad bearing one short claw curved distally; ambulacra II-III with empodial pads and two symmetrically paired claws. Leg chaetotaxy ( Figs. 15–16 ): Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: leg I: 3–4–6(1 φ )+7(1 ω ); leg II: 3–3–4–4(1 ω ); leg III: 1+1–4–4; leg IV:1+1–1+1. Setae present on each leg segment: Leg I: femur I: d 6 (5–6) (~ 0.5x LFeI) serrate, l' 8 (8–9) (~ 0.6x LFeI) smooth, v" 6 (~ 0.5x LFeI) smooth; genu I: l' 9 (8–9) (~ 1.0x LGeI) serrate, l" 6 (5–6) (~ 0.7x LGeI) serrate, v' 5 (4–5) (~ 0.6x LGeI) smooth, v" 7 (7–8) (~ 0.9x LGeI) smooth; tibiotarsus I: (setae): d 28 (28–31) (~ 1.9x LTbTaI) serrate, l' 17 (17–19) (~ 1.1x LTbTaI) serrate, l" 12 (12–13) (~ 0.8x LTbTaI) serrate, v' 13 (13–14) (~ 0.9x LTbTaI) serrate, v" 16 (16–17) (~ 1.1x LTbTaI) serrate, k 5 (~ 0.3x LTbTaI), pv' 6 (~ 0.3x LTbTaI) smooth, pv" 8 (8–9) (~ 0.6x LTbTaI) smooth, s 2 (~ 0.1x LTbTaI) spine-like, (eupathidia): p' 11 (~ 0.7x LTbTaI), p" 17 (~ 1.1x LTbTaI), tc' 16 (16–17) (~ 1.1x LTbTaI), tc" 18 (17–18) (~ 1.2x LTbTaI), (solenidia): cluster incomplete, inserted at same level: solenidion φ1 3 (~ 0.2x LTbTaI) slender and clavate; solenidion ω 7 (6–7) (~ 0.4x LTbTaI), fusiform. Leg II: femur II: d 6 (5–6) (~ 0.5x LFeII) serrate, l' 7 (7–8) (~ 0.5x LFeII) smooth, v" 14 (13–15) (~ 1.2x LFeII) smooth; genu II: l' 13 (12–13) (~ 1.9x LGeII) serrate, l" 6 (6–7) (~ 1.0x LGeII) serrate, v' 15 (14–15) (~ 2.1x LGeII) serrate; tibia II: d 13 (12–13) (~ 1.9x LTbII) serrate, l' 13 (13–14) (~ 1.9x LTbII) serrate, v' 14 (~ 2.0x LTbII) serrate, v" 14 (14–16) (~ 2.0x LTbII) serrate; tarsus II: tc' 10 (9–10) (~ 1.2x LTaII) smooth, tc" 9 (~ 1.1x LTaII) serrate, pv' 14 (13–14) (~ 2.0x LTaII) serrate, u' 3 (~ 0.4x LTaII) spine-like, (solenidia): solenidion ω 6 (~ 0.4x LTaII) proximally inserted, stout, fusiform. Leg III: femorogenu III: v' F 7 (~ 0.4x LFeGeIII) smooth, l' G 10 (9–10) (~ 0.6x LFeGeIII) smooth; tibia III: d 10 (9–10) (~ 0.6x LTbIII) smooth, l' 14 (14–15) (~ 0.8x LTbIII) serrate, v' 9 (9–10) (~ 0.5x LTbIII) serrate, v" 9 (9–10) (~ 0.5x LTbIII) smooth; tarsus III: tc' 13 (12–13) (~ 1.3x LTaIII) serrate, tc" 18 (18–20) (~ 1.8x LTaIII) serrate, pv' 12 (11–12) (~ 1.2x LTaIII) smooth, u' 3 (~ 0.2x LTaIII) spine-like. Leg IV: femorogenu IV: v' F 8 (7–9) (~ 0.5x LFeGeIV) smooth, v' G 9 (9–11) (~ 0.6x LFeGeIV) smooth; tibiotarsus IV: v' Ti 22 (21–24) (~ 2.9x LTbTaIV) falcate, tc" 35 (32–37) (~ 3.5x LTbTaIV) smooth. FIGURE 10. Ceratotarsonemus amazonicus , sp. nov. : details of dorsal setae. FIGURE 11. Ceratotarsonemus amazonicus , sp. nov. : ventral surface. FIGURE 12. Ceratotarsonemus amazonicus , sp. nov. : ventral surface: A—phase contrast; B—differential interference contrast; C—low temperature scanning electron microscopy. FIGURE 13. Ceratotarsonemus amazonicus , sp. nov. : details of the internal structures under the differential interference contrast (DIC) microscopy: A—gastric caecae; B—seminal receptacle and duct leading to ovary. FIGURE 14. Ceratotarsonemus amazonicus , sp. nov. : A–B: details of the external and internal structures under confocal laser scanning microscopy (CLSM) microscopy. Male and Larva : unknown. Type material: holotype and 19 paratypes on Psychotira sp. ( Rubiaceae ), four paratypes on Bignoniaceae sp. and one paratype on Annonaceae sp., 58°14ʹW 9°51ʹS, Cotriguaçú, State of Mato Grosso, Brazil, 01/II/2015 , A. C. Lofego, F. S. R. Amaral & J. M. Rezende. Holotype and 15 paratypes deposited at DZSJRP; 10 paratypes deposited at USNM. Remarks. Females of Ceratotarsonemus amazonicus sp. nov. are most similar to those of Ceratotarsonemus alas Ochoa & Vargas in having tergite C with reticulation forming a broad inverted U-shape, the reticula wider than long, identical lengths of dorsal setae sc1 and f , and the sejugal apodeme well defined along its whole extension. Female C. amazonicus , sp. nov. are distinguished by the length of their dorsal setae c2 and e (~ 30% longer than female C. alas , for both pairs of setae) and by the number of reticula rows on tergite C (four rows observed in C. amazonicus sp. nov. whereas just two in C. alas ). Etymology. The species is named amazonicus indicating the biome where the species has been found.