Prendalona sp.

39. ** Prendalona sp.

( Fig. 4A–F View FIGURE 4 )

Localities and specimens found: 50 – 1♀.

Distribution and ecology. This peculiar female was found amid the roots of a water hyacinth (see Appendix 1).

Remarks. Based on the main diagnostic characteristics, this unidentified individual most likely belongs to the genus Prendalona and is most similar to P. (formely Alona ) guttata (Sars, 1862) ( Sousa et al. 2016 a, 2018; Sinev et al. 2023a). At the same time, it has a number of noticeable differences from P. guttata and other representatives of the genus; mainly the presence of atypically long (up to 38 μm) setae on the posterior parts of the ventral margin of the valves ( Fig. 4A, B View FIGURE 4 ) (in other species, these setae are distinctly shorter) and the presence of a noticeably longer and thicker setula in the distal part of the groups of lateral setulae of the postabdomen ( Fig. 4A, C, F View FIGURE 4 ) (in other species, these groups have the other configuration of the setulae in length and thickness) ( Sinev et al. 2023a). Unfortunately, the only specimen found does not allow for a complete analysis of the morphological structure. It is possible that this is a new representative of the chydoridae. Further finds and study of more specimens are needed to clarify the status of this form.