Metanalges (Metanalges) agachi, Waki & Mironov & Nakaya & Nagamine & Shimano, 2024

Waki, Tsukasa, Mironov, Sergey, Nakaya, Yumiko, Nagamine, Takashi & Shimano, Satoshi, 2024, A New Feather Mite Species of the Genus Metanalges (Acariformes: Analgidae) from the Okinawa Rail, Hypotaenidia okinawae (Gruiformes: Rallidae), in Okinawa Island, Japan, Species Diversity 29 (1), pp. 161-169 : 164-167

Metanalges (Metanalges) agachi

Waki, Mironov, and Shimano, sp. n. ( Figs 1–5 ) [New Japanese name: Yanbarukuina-umou-dani]

Type materials. Holotype male ( MPM Coll. No. 25250) and paratypes, 2 males and 3 females ( MPM Coll. Nos 25251–25253), from the Okinawa Rail Hypotaenidia okinawae ( Yamashina and Mano, 1981) ( Gruiformes : Rallidae ), Japan, Okinawa Prefecture, Kunigami Village , March–April 2019 (holotype, 2 male and 1 female paratypes), and May 2013 (2 female paratypes), mite coll. T. Waki.

Depository. Meguro Parasitological Museum ( MPM), Tokyo, Japan .

Description. Male (holotype, range for 2 paratypes in parentheses) ( Figs 1A , 2 , 3). Total body length including gnathosoma 684 (709–737). Length of subcapitulum including palps 67 (55–74), greatest width of subcapitulum 57 (64–65). Idiosoma length 622 (643–681), greatest width (at level of setae c3) 286 (294–306). Prodorsal shield shaped as elongate trapezoid, lateral margins slightly concave, length along midline 97 (94–116), greatest width at posterior margin 98 (107–116). Setae ve represented by alveoli. Scapular shields well developed. Length of hysterosoma 513 (525–545). Humeral shields not developed dorsally. Hysteronotal shield covering most of dorsal hysterosoma, split into prohysteronotal and lobar pieces, surface without ornamentation, total length 453 (443–450). Prohysteronotal shield almost quadrangular in shape, length along midline 207 (182–186), width at anterior margin 179 (169–176), width at posterior margin 181 (175–180). Length of lobar shield 270 (260–265). Lateral margins of opisthosoma between levels of setae e2 and f2 with narrow opisthosomal membranes with smooth free margin. Opisthosomal lobes strongly elongated, over 3 times longer than wide at midlevel, straight or slightly curved medially, lateral margins from bases of setae h2 to setae h3 with narrow lateral membranes, width of opisthosomal lobes at midlength excluding membranes 58 (59–62). Terminal cleft narrow, parallel-sided or narrowly ovate; supranal concavity fused with the cleft, length of terminal cleft 152 (144–147), total length of the cleft including concavity 223 (209–220), greatest width 67 (66). Interlobar membrane occupying entire margin of terminal cleft, extending to lobar apices and forming rounded terminal extensions extending slightly beyond apices. Incision in interlobar membrane narrow, almost parallel-sided, length from anterior end to margins of terminal extensions 138 (141–142), greatest width 15 (11–19). Setae f2, h2, and h3 represented by macrosetae, setae ps2 filiform, about 3/4 the length of opisthosomal lobes. Macrosetae h2 situated approximately at level of anterior 1/4 of opisthosomal lobes, macrosetae h3 near lobar apices. Setae ps1 equidistant from levels of setae h2 and h3, or slightly closer to setae h2. Distances between dorsal setae: se–se 99 (91–92); si–si 82 (74); h2–h2 155 (139–145); h3–h3 97 (64–91); c2–d2 153 (151– 163); d2–e2 99 (84–85); e2–h3 247 (248–260). Lengths of dorsal setae: vi 18 (12–13); si 44 (37–62); se 218 (217–255); c2 99 (97–140); c3 85 (94–105); cp 139 (133–138); d2 34 (29–37); e2 124 (143–157); f2 227 (237–240); ps1 48 (53– 78); h2 412 (442–443); h3 366 (358–405).

Epimerites I fused in a V, fused part with thin spiculiform extension. Coxal fields III closed. Genital apparatus situat- ed at levels of trachanters IV. Genital arch 12 (10–16) × 26 (26–34), aedeagus minute, much shorter than arch. Paragenital apodemes small, fused into a low arch anterolateral to genital apparatus. Anterior pair of genital papillae on soft tegument or on paragenital apodemes, and posterior pair of papillae on paragenital apodemes. Adanal shield roughly trapezoidal, posterior margin with wide median extension partly covering anal opening, lateral parts with band-like oblique adanal apodemes extending to bases of setae ps2. Ventral side of opisthosomal lobes not sclerotized. Cupules ih well developed. Distances between ventral setae: 4b–g 95 (94–110); 4b–4a 52 (50–54); 4a–g 52 (50–60); 4a–ps3 112 (125–127). Lengths of ventral setae: 1a 57 (33–54); 3a 81 (68–79); 4a 50 (42–51); 4b 117 (109–124); g 49 (56–57); ps2 81 (78–90); ps3 29 (29–35).

Legs ( Fig. 3A–D). Femur I with small acute denticle on lateral margin. Genual solenidion σ2 I slightly longer that genu I. Tarsus III with conical apical extension with bidentate apex, setae s large spine-like with narrow bidentate apex. Apical extension of tarsus IV with conical bidentate apex; modified setae d and e button-like. Lengths of tarsi I–IV: 51 (47–48), 55 (56–60), 66 (58–63) and 39 (45–51). Lengths of solenidia: ω1 I 48 (52–55); ω3 I 43 (44–49); ω1 II 41 (45–48); σ2 I 76 (82–83); σ II 16 (13–18); σ III 55 (34–42).

Female (range for 3 paratypes) ( Figs 1B , 4 , 5 ). Total body length including gnathosoma 466–554. Gnathosoma as in male, length of subcapitulum including palps 62–67, greatest width 56–70. Length of idiosoma 423–517, greatest width (at level of setae c3) 218–255. Prodorsal shield shaped almost as in male, but posterior margin with short median convexity, length along midline 109–118, width at posterior margin 120–125. Setae ve represented by alveoli. Scapular shields well developed. Humeral shields not developed dorsally, represented by small triangular plates on ventral side of hysterosoma anterior to epimerites III. Length of hysterosoma 295–369, posterior end widely rounded. Hysteronotal shield absent, entire dorsal surface covered with soft tegument with pronounced and deep striae. Copulatory opening on minute cone-shaped extension on posterior margin of opisthosoma. Distances between dorsal setae: se–se 98–104; si–si 79–89; h2–h2 82–100; h3–h3 60–81; c2–d2 115–120; d2–e2 106–125; e2–h3 94–131. Lengths of dorsal setae: vi 19–25; si 11–19; se 170–215; c2 51–61; c3 65–78; cp 122–125; d2 28–31; e2 121–141; h2 335–391; h3 217–264; ps1 20–31.

Epimerites I shaped as in male. Epigynum shaped as small low bow, 11–17 wide, situated between bases setae 4b. Coxal setae 4a almost extending to posterior margin of opisthosoma. Setae ps3 extending beyond posterior margin of opisthosoma. Distances between ventral setae: 1a–4b 52–56, 4b–g 37–58; g–4a 64–72, 4a–ps3 133–171. Lengths of ventral setae: 1a 30–41; 3a 35–48; 4a 123–141; 4b 65–109; g 77–120, ps3 69–77.

Legs. Setae s of tarsi III and IV thick spine-like, with a pair of minute denticles on apex. Lengths of tarsi I–IV: 42– 47; 48–53; 52–58; 61–74. Lengths of solenidia: ω1 I 39–46; ω3 I 41–46; ω1 II 33–44; σ2 I 71–81; σ II 14–18; σ III 37–41.

Differential diagnosis. Metanalges agachi sp. n. belongs to the subgenus Metanalges s. str. and is most close to M. curtus Gaud and Mouchet, 1959 in sharing the following characters in males: the opisthosomal lobes are narrow and strongly elongated (about 3 times longer than wide at their midlength), the terminal cleft is long with parallel or slightly concave margins the incision in the interlobar membrane is narrow and parallel-sided, the posterior ends of interlobar membrane have short and rounded terminal projections extending beyond the lobar apices. Males of M. agachi differ from those of M. curtus in the following features: legs III with the pretarsus extend slightly beyond the level of setae h2, setae ps1 are situated at the midlength between levels of setae h2 and h3 or slightly closer to h2. In males of M. curtus , legs III with pretarsus extend almost to the level of setae h3 situated on the lobar apices, and setae ps1 are situated almost at the levels of setae h2. In the three previously known species of the subgenus Metanalges s. str. having strongly elongated opisthosomal lobes, M. curtus , M. elongatus and M crexi Mironov, 1981 , females are known only in the latter; therefore, females of M. agachi can be compared only with that species. In females of M. agachi , the posterior margin of the prodorsal shield is slightly convex (vs. straight in M. crexi ), coxal setae 4a almost extend to the posterior margin of opisthosoma (vs. not extending to anal opening), and setae ps3 extend beyond the posterior margin of opisthosoma (vs. not extending).

Etymology. The specific name is a transliteration of the local name of the type host (“Agachi”), and is thus treated as indeclinable. This name, meaning a flustered person, has been used by the local residents of former forested area in the northern part of Okinawa Island (“Yanbaru” region), before the bird was given a scientific name and Japanese name “Yanbaru-kuina (Rail)”.

DNA markers. INSD accession numbers: LC781786– LC781789 (COI, 637 bp).

Figures

Fig. 1. Metanalges agachi sp. n., male, MPM Coll. No. 25251 (A) and female, MPM Coll.No. 25252 (B), ventral views. Scale bars: 50µm.

Fig. 2. Metanalges agachi sp. n., male, MPM Coll. No. 25250. A, Ventral view; B, dorsal view.

Fig. 4. Metanalges agachi sp. n., female, MPM Coll. No. 25252. A, Ventral view; B, dorsal view.

Fig. 5. Metanalges agachi sp. n., female, MPM Coll. No. 25253. A–D, Legs I–IV.