Momonia (Kondia), 1974

AbéK, Hiroshi, IwasaK, Masahiro A. & Morimoto, Shizuko, 2024, Synonymy of the water mite subgenera Orientmomonia and Kondia in the genus Momonia (Momoniidae, Acari): an evaluation based on morphology and molecular data, Acarologia 64 (2), pp. 353-362 : 357-360

Momonia (Kondia) sp.

Specimens examined — One female, from the Otani River, Dec. 25, 2019, K. Inada leg.; 27 females, the same locality as above, Nov. 20, 2021, Jan. 14 and 23, 2022, K. Inada and S.

Morimoto leg.; one female, the Imotani River, March 3, 2022, Inada leg; two females, the same locality as above, March 16, 2022, Morimoto leg; three females, the Syushi River, Dec. 31,

2022, S. Morimoto leg.

Characteristics — Light green body with dark red eyes ( Fig. 2B ). Idiosoma soft and round; anterior dorsal portion with a depression and two pairs of round dorsal muscle insertion platelets, anterior pair 31–35 and posterior pair 25 in diameter; posterior dorsal part with a pair of small pores and two pairs of non-glandular setae arranged in a rectangular shape ( Fig. 4A ). Right and left Cx-I–IV widely separated in the unmounted specimen ( Fig. 4B ), whereas sometimes closer due to artificial deformation ( Fig. 4C ); Cx-III with a long seta on anterolateral corner; Cx-IV greatly expanding posteriorly as well as laterally, posterolaterally rounded, with almost 15 setae in posterolateral area. Genital plates elongated bearing three pairs of acetabula. P-1–5 with 1, 5, 4, 7, 6 setae (including spine and claw), respectively ( Fig. 4D ); P-4 with two ventral spines and one anterodorsal peg-like spine; distal two filiform setae on P-3 and most filiform setae on P-4 long and slender. I-L-5 more than three times longer than I-L-6, 1.58–1.68 times higher than I-L-4; ratio of length to height 5.69–6.37 in I-L-5, 1.31–1.72 in I-L-6 ( Fig. 4E ); III-L-3–5 and IV-L-3–5 each with 1–3, 3–5, 2–3 distal, long swimming setae and sometimes also with plumose spines ( Fig. 4F ).

Measurements (n = 6) — Idiosoma ventral L/W 607–779/541–713, dorsal L 525–656.

P-1–5 L: 27–41, 78–95, 46–61, 82–105, 50–69. Cx-I–II L/W 135–170/205–270. Cx-I–

IV L 443–526. Genital field L/W 160–220/110–143; Genital plate L/W 100–126/29–36. Gnathosoma L 130–162. Chelicera L 126–149. I-L-1–6 L: 41, 98–135, 152–193, 160–201,

312–394, 98–123; I-L-4–6 H: 31–37, 49–62, 57–82; I-L-5 L/I-L-6 L ratio 3.14–3.60, I-L-5

H/I-L-4 H ratio 1.58–1.68, I-L-5 L/I-L-5 H ratio 5.69–6.37, I-L-6 L/I-L-6 H ratio 1.31–1.72; IV-L-3–6 L: 103–148, 156–205, 205–253, 164–230.

Remarks — Main characteristics of the female are the soft body, the presence of two pairs of round dorsal muscle insertion platelets on the anterior half of the dorsum, two pairs of setae on the posterior dorsal portion, long filiform seta on the anterior corner of Cx-III, and widely separated right and left Cx-I–IV. These features are applicable to the monotypic subgenus Kondia originally established by Sokolow (1926). At present, only females of a single species Momonia (Kondia) karelica are known. This species was originally recorded in the Republic of Karelia in the north-western part of Russia. Afterwards, this species was recorded also from Gästrikland on the eastern coast of Sweden by Lundblad (1962). Specific features and illustrations of M. (K.) karelica in Cook (1974) (Fig. 1628) and Smit (2020)

(Fig. 3008) probably referred to Lundblad (1962) (Fig. 409) instead of the original description by Sokolow (1926). However, the trouble is that taxonomic features of this species given in Lundblad (1962) are slightly different from those in Sokolow (1926). The main differences based on the illustrations are as follows (features in Lundblad (1962) are given in parenthesis): The anterior end of Cx-I is not protruded forward from the anterior margin of the dorsum (clearly protruded); the posterior two-thirds of the genital plate beyond posteriorly to the level of posterior margin of Cx-IV (half of the genital plate). This cannot exclude the possibility that the female in Lundblad (1962) was not M. (K.) karelica . Therefore, we compared the present females only with M. (K.) karelica in the original descriptions by Sokolow (1926).

The results of morphological comparisons between these two species are as follows (features of M. (K.) karelica are indicated in parenthesis): The posterior pair of the round dorsal muscle insertion platelets are 25 in diameter (12 in diameter); two pairs of dorsal setae on the posterior part of the dorsum are arranged to form a rectangle (inverted trapezoid); the anterior end of Cx-I protruded forward from the anterior margin of the dorsum (not protruded); about one-quarter of the genital plates beyond posteriorly to the level of posterior margin of Cx-IV (more than half of the genital plate); anterior margin of the genital plate with three setae (two setae). Due to the morphological differences mentioned above, it can be concluded that the present female is not M. (K.) karelica .

Figures

Figure 2 Dorsal aspect of the unmountedMomoniaspecies. A – male of Momonia(Orientmomonia) koreana; B – female of Momonia(Kondia) sp. Scale bar: 200 μm.

Figure 4 Female of Momonia(Kondia) sp. A – dorsal view of idiosoma; B – ventral aspect of unmounted specimen; C – ventral view of idiosoma; D – right palp; E – I-L-1–6; F – IV-L-3–6. Scale bars: 100 μm.