Zaitzevia tsushimana Nomura 1963
Creators: name: Hayashi, Masakazu
name: Kamite, Yuuki
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Elmidae
Zaitzevia
Zaitzevia tsushimana

description: Zaitzevia tsushimana Nomura, 1963
(Figs 2F, G, 16, 19G, 20J)
Materials examined. JAPAN: [TSUSHIMA]: 3 larvae, Nakayama-gawa, Sago, Kamiagata-chô, Nagasaki Pref., Tsushima Island, 19.iv.2018, M. Hayashi leg.
Description. Body length of mature larva ca. 4.0 mm in expanded specimen.
Body elongate, narrowing from thorax to apex; convex dorsally and flattened ventrally; semicircular in cross section; spiracles on mesothorax and abdominal segments I–VIII. Body color black or dark brown, and appendages orange colored. Dorsal and ventral surfaces entirely not smooth with flat granules (Fig. 16B, D; Kodada et al. 2016: 583) and various types of setae.
Head visible from above, well exposed from prothorax; as wide as long; clypeus transverse, setose; without a pair of spines on both sides of clypeus (frontal tooth); vertex rugose with brush-like setae; eyes large but lens of stemmata absent. Antenna with three antennomeres; antennomere 1 shorter than antennomere 2, short branched setae; antennomere 2 with long sensorial appendage; antennomere 3 short with small sensorial appendage. Maxillae and labium forming a unit (maxillolabial unit). Maxilla with four palpomeres; cardo small; stipes large; galea and lacinia separate, setose apically. Labium narrow with two palpomeres; ligula short and transverse; mentum long; submentum short and transverse.
Thorax not serrated on lateral sides; dorsum entirely not smooth with granules and flat brush-like setae (Fig. 19G). Prothorax wider than long, 2 times as long as mesothorax; with glabrous smooth area on dorsum; with seven ventral sclerites (one between coxae, two anteromedial, two anterolateral, and two posterolateral), procoxae not closed posteriorly; flat feather-like setae on hind margins. Meso- and metathorax transverse; metathorax slightly longer than mesothorax; with five ventral sclerites (one large anteromedial, two anterolateral, and two posterolateral).
Abdomen 9-segmented; segments I–VIII transverse, dorsal surface entirely not smooth with granules; pleural sclerites on segments I–VII. Last segment (segment IX) longer than wide, gradually narrowing to apex; tergal surface with minute and coarse granules; with ridge on both sides (Fig. 16E); with longitudinal ridge on meson; apex notched; ventrally flat, with subpentagonal-shaped operculum, opercular claws, and anal gills.
Habitat. Upper to middle stream reaches; larvae live in the gravel substrate.
Identification. The larva was identified by association with adult Z. tsushimana from Tsushima Island, Nagasaki Pref., because the genus Zaitzevia fauna of the island includes only Z. tsushimana.
Distribution. Tsushima (type locality), Korea, China, Far East Russia.
Bibliography. The larva of this species is described here for the first time.
description: Published as part of Hayashi, Masakazu & Kamite, Yuuki, 2020, Description of larvae of Japanese Macronychini (Coleoptera: Elmidae: Elminae), pp. 195-227 in Zootaxa 4859 (2) on pages 224-225, DOI: 10.11646/zootaxa.4859.2.2, http://zenodo.org/record/4412885