Ilyocryptus cuneatus Štifter, 1988

Kotov, Alexey A., Jeong, Hyun Gi & Lee, Wonchoel, 2012, Cladocera (Crustacea: Branchiopoda) of the south-east of the Korean Peninsula, with twenty new records for Korea *, Zootaxa 3368, pp. 50-90 : 61-62

publication ID	https://doi.org/ 10.5281/zenodo.214313
DOI	https://doi.org/10.5281/zenodo.5680411
persistent identifier	https://treatment.plazi.org/id/03B687AA-FFBC-5A4F-25DC-9D83FC64FDF1
treatment provided by	Plazi
scientific name	Ilyocryptus cuneatus Štifter, 1988
status

Treatment

6. Ilyocryptus cuneatus Štifter, 1988 View in CoL

Figs 8–9 View FIGURE 8 View FIGURE 9

Synonymy. Ilyocryptus cuneatus Štifter, 1988 , p. 292–296, Figs 7–19 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19 ; Tanaka 2001, p. 221, Fig. 3 View FIGURE 3 A–E; Kotov & Štifter 2006, p. 76–81, Figs 2 View FIGURE 2 G, 35–38; Kotov et al. 2011a, p. 405.

Type locality. “West Bohemia, Březová reservoir on the river Teplá, 5 km south of Karlovy Vary” ( Štifter 1988), Czech Republic.

Localities in Korea. 6a, 7b, 8, 14 (see Fig. 1 and Table 1 View TABLE 1 ).

Parthenogenetic female. Body triangular-ovoid, postero-dorsal angle expressed ( Fig. 8 View FIGURE 8 A). In anterior view, body thick, with thick and low dorsal keel, without lateral horns. Moulting incomplete. Ocellus small ( Fig. 8 View FIGURE 8 B). Head shield with mandibular articulation as a small projection ( Fig. 8 View FIGURE 8 C). Setae at ventral margin plumose ( Fig. 8 View FIGURE 8 D). Each seta at posterior margin with a long, stout basal part, than with a series of 2–4 stout spine-like setules along one side in its basal portion, and with fine hairs in distal portion ( Fig. 8 View FIGURE 8 E). Anus opens in the middle between base and distal extremity of postabdomen; preanal teeth 10–12, subequal in size, both doubled and single in the same specimen, few denticles on postabdomen base laterally ( Fig. 8 View FIGURE 8 F). Paired spines shorter than large lateral setae. Postabdominal claw with a single denticle in distal part, no denticles in its middle part, distal and proximal spines on claw base subequal in size; setules situated on base of claw ventrally long ( Fig. 8 View FIGURE 8 G). Antenna I relatively long, with transverse ridges ( Fig. 8 View FIGURE 8 B). Proximal segment with a finger-like projection and few low hillocks ( Fig. 8 View FIGURE 8 H). The longest aesthetasc about half the distal segment. Antenna II short, distal burrowing spine relatively short, with tip almost reaching or reaching distal border of basal segment ( Fig. 9 View FIGURE 9 A). Both antennal branches short ( Fig. 9 View FIGURE 9 B–C). Apical swimming setae relatively short, armed with short setules distally ( Fig. 9 View FIGURE 9 D). Proximal lateral swimming seta shorter than distal one, both without hooks on tips and armed along one side with setules analogous to these of apical setae, and more stout and long setules along other side ( Fig. 9 View FIGURE 9 E–F). Spine on second segment of exopod equal to or somewhat shorter than half of third segment ( Fig. 9 View FIGURE 9 B–C). A large seta near ejector hooks of limb I. Gnathobase I as a setulated hillock. Limb VI with row of long setules along inner margin subdivided into six bundles by small incisions on the margin. Size in our material 0.61–0.83 mm.

Notes. The species is widely distributed in the Northern Palaearctic and Nearctic ( Kotov & Štifter 2006) and found close to Korea: Japan ( Tanaka 2001) and the Amur basin in Far East of Russia, where it is quite common ( Kotov et al. 2011a). We found it also to be common in the Korean Peninsula, which could be the southernmost area of its distribution in Asia. Unfortunately, there is no information on its presence in China, and previous descriptions of ilyocryptids ( Chiang & Du 1979) are not detailed enough to separate sordidus -like species sensu Kotov & Elías-Gutiérrez (2009). Korean specimens are somewhat different from European ones in: (1) only few denticles on postabdomen base laterally; (2) ridges, although ill-expressed, on distal segment of antenna I. It is possible that populations from the Far East form a separate taxon, but this idea could be confirmed only in the course of a global revision of the cuneatus -like populations in the Palaearctic.