Interrhodeus brevicornus Karg, 2000

Castilho, Raphael C., De, Gilberto J. & Halliday, Bruce, 2012, Revision of the genera Interrhodeus, Pennarhodeus and Poropodalius (Acari: Rhodacaridae), Zootaxa 3335, pp. 1-28 : 2-5

Interrhodeus brevicornus Karg, 2000

Interrhodeus brevicornus Karg, 2000a: 259 .

Specimens examined. Holotype female: 6953 T, IB1418905, La Selva , Heredia , Costa Rica (10°26’0”N 84°1’0”W), elev. 50–150 m, Coll. Alas, 6-XI-1993, ZMB Kat. Nr. 46010, [ Costa Rica INBIO CRI001418905 ]. Paratypes: one female, 6954, IB1418902, ZMB Kat. Nr. 46011, [ Costa Rica INBIO CRI001418902 ]; one female, 6955, IB1418922, ZMB Kat. Nr. 46012, [ Costa Rica INBIO CRI001418922 ]; one female, 6956, IB1419397, Ex. Hernandia didymantha Hernandiaceae , 12-X-1994, ZMB Kat. Nr. 46013, [ Costa Rica INBIO CRI001419397 ]; one female, 6957, IB1422099, Suampo experimental , 20-I-1995, ZMB Kat. Nr. 46014, [ Costa Rica INBIO CRI001422099 ]; one deutonymph, D-N 6958, IB1419233, SSO 350m, 3-IX-1993, ZMB Kat. Nr. 46015, [ Costa Rica INBIO CRI001419233 ]; one deutonymph, D-N 6959, IB1418871, ZMB Kat. Nr. 46016, [ Costa Rica INBIO CRI001418871 ] (for all paratypes, other data as for holotype). (in MNHB).

Diagnosis of adult. As for the genus.

Adult female ( Fig. 1 A–F) (holotype and four paratypes). Dorsal and ventral idiosomal, hypostomal, subcapitular and leg setae smooth.

Gnathosoma: Fixed cheliceral digit 34 long, with five teeth in addition to apical tooth and a setiform pilus dentilis ( Fig. 1 A); movable cheliceral digit 35 long, with four teeth in addition to apical tooth. Arthrodial process of chelicera with a short coronet-like fringe. Epistome with a serrate antero-medial projection of about uniform width and provided with two apical denticles, flanked on each side by a slightly longer, triangular and serrate projection ( Fig. 1 B); margin of epistome smooth between antero-medial and antero-lateral projections, and serrate laterad to antero-lateral projections. Deutosternal denticles in eight rows, with seven to 13 denticles each; anterior row anteriorly convex, other rows straight and roughly transverse, second last row narrow ( Fig. 1 C). Measurements of setae: h 1 14–17, h 2 13–15, h 3 10–12, sc 11–14.

Dorsal idiosoma ( Fig. 1 D). Podonotal shield ornamented with roundish markings, except for a punctate band along posterior margin; 158–163 long and 171–185 wide at widest point; with 22 pairs of setae (setae s1 and r1 absent); without scleronoduli and with five pairs of distinguishable lyrifissures. Opisthonotal shield imbricate, with roundish markings behind setae Z4 and a punctate band along anterior margin; 131–146 long and 135–142 wide at widest point; with 20 pairs of setae and four pairs of distinguishable lyrifissures. Measurements of setae: j 1 17–19, j 2 18–19, j 3 15–16, j 4 13–15, j 5 14–15, j 6 13–14, z 1 18–19, z 2 16–18, z 3 14–15, z 4 14–15, z 5 12–14, z 6 12–13, s 2 15 –16, s 3 14 –15, s 4 14 –15, s 5 13 –15, s 6 12 –13, r 2 14–15, r 3 18–20, r 4 13–14, r 5 13–14, r 6 14–15, J 1 12–13, J 2 12–13, J 3 12–14, J 4 13–15, J 5 15–16, Z 1 13–14, Z 2 13–14, Z 3 13–15, Z 4 15–16, Z 5 19–21, S 1 12 –14, S 2 12 –13, S 3 14 –15, S 4 16 –17, S 5 19 –20, R 1 12–13, R 2 12–14, R 3 14–15, R 4 16–17, R 5 19–20.

Ventral idiosoma ( Fig. 1 E). Base of tritosternum 14–21 long and 12–13 wide proximally ( Fig. 1 F); laciniae 43–51 long, separated for about half of their total length, pilose. Sternal shield lightly reticulate and with indistinct anterior margin; region anterior to the first pair of lyrifissures (iv 1) lightly sclerotised and punctate; posterior margin straight; approximately 88–93 long, including the lightly sclerotised and punctate region, and 73–77 wide at widest point; with four pairs of setae and three pairs of lyrifissures. Triangular remnants of exopodal shield distinguishable between coxae II–III and III–IV. Elongate remnant of endopodal shield distinguishable adjacent to coxa IV and slightly anterior to it. Genital shield with light striae parallel to lateral margins, and a punctate band along most of its slightly convex posterior margin; longer than wide; extending posteriorly behind coxa IV; distance between st 5– st 5 45–48. Unsclerotised integument posterolaterad to st5 with a pair of lyrifissures. Ventrianal shield reticulate, except for a punctate band along anterior margin; 91–102 long and 90–102 wide at widest point, not fused to dorsal shield; with five pairs of setae (Jv1–Jv3, Zv1 and Zv2) in addition to circum-anal setae; post-anal seta as long as para-anal setae; lyrifissures not distinguishable. Unsclerotised integument around ventrianal shield with two pairs of setae (Jv5 and Zv3) and a pair of elongate metapodal plates. Peritreme extending anteriorly to mid-level of coxa II. Peritrematal shield fused with a section of exopodal shield next to coxa IV. Measurements of setae: st 1 18–20, st 2 17–18, st 3 16–18, st 4 14–16, st 5 14–15, Jv 1 14–15, Jv 2 15–16, Jv 3 16–17, Jv 5 14–16, Zv 1 13–14, Zv 2 15–16, Zv 3 14–15, para-anal 15–16, post-anal 16–18.

Legs. Lengths: I: 303–312; II: 223–234; III: 203–220; IV: 281–295. Pretarsi I–IV similar in shape and length, an elongate ambulacral stalk, a pair of strong claws and three rounded pulvillar lobes.

Deutonymph ( Fig. 2 A–B) (two paratypes). Shape of setae as in adult female.

Gnathosoma. Fixed cheliceral digit 28–29 long, with five teeth in addition to apical tooth, and a setiform pilus dentilis; movable cheliceral digit 28–30 long, with four teeth in addition to apical tooth. Arthrodial process of chelicera with a short coronet-like fringe. Epistome, deutosternum and position of hypostomal setae as in female. Measurements of setae: h 1 16, h 2 12–13, h 3 10, sc 14–15.

Dorsal idiosoma ( Fig. 2 A). Podonotal shield imbricate laterad to j setal series and with roundish markings between j series; 132–133 long and 143–147 wide at widest point; with 21 pairs of setae (setae s1 and r1 absent); without scleronoduli and with five pairs of distinguishable lyrifissures. Unsclerotised integument laterad to podonotal shield with a pair of setae (r4). Opisthonotal shield mostly imbricate, except for a narrow band of roundish markings along anterior margin; 110–122 long and 104 wide at widest point; with 15 pairs of setae and four pairs of distinguishable lyrifissures. Unsclerotised integument laterad to opisthonotal shield with five pairs of setae (R1–R5). Measurements of setae: j 1 16–17, j2 18, j3 15, j4 13, j 5 13–14, j 6 11–13, z 1 15–16, z 2 15–16, z 3 12–13, z 4 12–13, z 5 11–12, z 6 11–12, s2 13, s 3 12 –13, s4 13, s 5 12 –13, s6 12, r 2 13–14, r 3 16–17, r4 11, r 5 11–12, r6 11, J 1 11–12, J2 11, J 3 10–11, J4 11, J5 12, Z 1 11–12, Z 2 10–11, Z 3 11–12, Z 4 13–14, Z 5 19–21, S 1 11 –12, S 2 10 –11, S 3 10 –11, S4 13, S5 15, R 1 9–10, R2 8, R3 8–9, R4 10, R 5 12–14.

Ventral idiosoma ( Fig. 2 B). Base of tritosternum 15–17 long and 11–13 wide proximally; laciniae 40–41 long, otherwise as in adult female. Sternal shield smooth, narrowing behind coxae II, with slightly rounded posterior margin; approximately 119–123 long and 58–59 wide at widest point; with four pairs of setae and three pairs of lyrifissures. Setae st5 inserted on unsclerotised integument at level of posterior end of sternal shield. Ventrianal shield imbricate; 45–56 long along midline and 57–58 wide at widest point; with two pairs of setae (Jv2 and Jv3) in addition to circum-anal setae; post-anal seta about as long as para-anal setae. Unsclerotised integument around ventrianal shield with five pairs of setae (Jv1, Jv4 and Zv1-Zv3). Peritreme extending anteriorly to mid-level of coxa II. Peritrematal shield indistinct. Measurements of setae: st 1 17–18, st 2 16–17, st 3 13–14, st 4 11–13, st 5 9–11, Jv 1 11–13, Jv2 12, Jv3 13, Jv 4 10–11, Zv 1 10–11, Zv 2 10–11, Zv3 8–9, para–anal 13–15, post-anal 15–16.

Legs. Lengths: I: 267–271; II: 198–201; III: 180–181; IV: 236–241. Leg chaetotaxy and pretarsi as in adult female.

Remarks. This species was described on the basis of the adult female holotype, 52 adult female paratypes and seven deutonymph paratypes. The following characteristics appear in the original description and illustrations of the species ( Karg, 2000a), but do not agree with our observations of female type specimens: movable cheliceral digit with three teeth in addition to apical tooth; most anterior row of deutosternal denticles roughly transverse; podonotal shield imbricate, with 21 pairs of setae, and with structures suggesting the presence of scleronoduli [ Karg (2000a) mentioned that scleronoduli were not clear]; unsclerotised integument laterad to podonotal shield with two pairs of setae; sternal shield smooth; exopodal shield consisting of a single structure between coxae II–IV; no endopodal shields; genital shield smooth; lyrifissures present only on podonotal (two pairs) and sternal shields (three pairs). No information was provided about the tritosternum. The only measurements provided in the original description referred to the length of the idiosoma (270–290), width of the idiosoma (140–180), length of seta J5 (cited as I5) (18), range of lengths of other dorsal idiosomal setae (15–16) and length of all st setae (18). Leg setal counts were given only for tibia IV (10 setae) and genu IV (10 setae).

The deutonymph was illustrated in the original description of the species, but not described (Figure 23 in Karg, 2000a). The following characteristics are present in the original illustrations of the deutonymph, but do not agree with our observations of the paratype specimens: podonotal shield smooth and with 23 pairs of setae; opisthonotal shield reticulate; ventrianal shield smooth; with a longitudinal line extending from the anterior end of the peritreme to the level of coxa I; lyrifissures present only on the sternal shield (two pairs).

Figures

FIGURE 1. Interrhodeus brevicornus Karg. Female. A. Lateral (antiaxial) view of chelicera; B. Epistome; C. Hypostome; D. Dorsal idiosoma; E. Ventral idiosoma; F. Tritosternum. Lyrifissures enlarged for improved visibility.

FIGURE 2. Interrhodeus brevicornus Karg. Deutonymph. A. Dorsal idiosoma; E. Ventral idiosoma. Lyrifissures enlarged for improved visibility.