Rhynchotalona kistarae, Roen, 1973

Damme, Kay Van & Nevalainen, Liisa, 2019, The most latent cladoceran in the Holarctic revealed-sinking Unapertura Sarmaja-Korjonen, Hakojärvi & Korhola, 2000 into the genus Rhynchotalona Norman, 1903 (Branchiopoda: Cladocera: Chydoridae), Zootaxa 4613 (3), pp. 463-476 : 470

Note on R. kistarae Røen, 1973

As R. latens shows closest affinities to the poorly known R. kistarae until the detailed limb features of both species can be examined, the general features of the Greenland species are shown again here, after the original description by Røen (1973) ( Fig 5 ). Sinev & Kotov (2014) consider this a valid species, which we agree with. In general habitus and size, R. kistarae resembles R. latens strongly ( Fig. 5A ), with a similar rostrum, curved inwards ( Fig. 5 A–B) yet the posterior marginal setae on the carapace are not as long in R. kistarae ( Figs 5A, C ). The labral keel ( Fig. 5D ) is similar in shape in both taxa, yet the marginal teeth on the postabdomen ( Figs 5 F–G) are different. In R. kistarae, Røen (1973) mentions that there are only two or three large teeth here with a gap ( Fig. 5F ), as opposed to five to six in a continuous row in R. latens . Also the head pore arrangement is different based on the drawings of Røen (1973): in R. kistarae , the lateral (small) pores are adjacent and more posterior relative to the major pore ( Fig. 5E ), as in the majority of Rhynchotalona species. However, we would like to note that strong care should be taken here until R. kistarae is revised in detail on material from Greenland, in particular to understand the variability of the postabdomen and to confirm the head pore arrangement. Molecular methods would help in the future to clarify Rhynchotalona systematics, including Røen’s peculiar taxon from Greenland.

Figures

FIGURE 5. Rhynchotalona kistarae Røen, 1973—Adult parthenogenetic female from Kap Farvel Area, Pamiagdiuq Island, Greenland, all images reproduced after the original drawings and description in Røen (1973). A, habitus, lateral view. B, detail of head; C, posteroventral valve setae. D, labral keel. E, headshield. F–G, postabdomen, complete overview (G) and marginal denticles (F); arrow in F points at the marginal denticle on the postanal corner.