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Ceriodaphnia cf. cornuta, adult parthenogenetic females from Masfoot Dam 1, United Arab Emirates. (a,b) adult females, lateral view; (c-e) head, lateral view; (f) head, ventral view; (g) rostrum, ventral view; (h,i) antenna I. Scale bars: 0.1 mm for (a,b), 0.05 mm for (c), 0.02 mm for (d-i).
Source publication
A study of the water fleas (Crustacea: Cladocera) in man-made lakes in the northeast part of the United Arab Emirates revealed five species: Ceriodaphnia cf. cornuta Sars, 1885; Daphnia (Ctenodaphnia) arabica Neretina, Al Neyadi et Hamza, 2022; Moina cf. micrura Kurz, 1875; Anthalona mediterranea (Yalim, 2005); Coronatella anemae Van Damme et Dumon...
Citations
... Recently, we established a program of cladoceran studies using genetic methods, in which we demonstrated the pre-Pleistocene relict status of some taxa [28] and found a very specific species of Daphnia (Ctenodaphnia) Dybowski et Grochowski, 1895, namely, D. (C.) arabica, known to derive from a single shallow water body that completely dries up in summer [29]. The aim of this article was to present the complete genomic analyses of this Daphnia species and reveal its differences from other species at the genomic level. ...
... This is consistent with the estimations by Hamza et al. [29] based only on three mitochondrial genes. Moreover, the entire Arid Belt of Eurasia could be particularly rich in pre-Pleistocene freshwater relicts [28], but such a hypothesis needs statistically accurate confirmation based on several cladoceran and non-cladoceran taxa. ...
The water flea Daphnia O.F. Müller 1776 (Crustacea: Cladocera) is an important model of recent evolutionary biology. Here, we report a complete genome of Daphnia (Ctenodaphnia) arabica (Crustacea: Cladocera), recently described species endemic to deserts of the United Arab Emirates. In this study, genome analysis of D. arabica was carried out to investigate its genomic differences, complexity as well as its historical origins within the subgenus Daphnia (Ctenodaphnia). Hybrid genome assembly of D. arabica resulted in ~116 Mb of the assembled genome, with an N50 of ~1.13 Mb (BUSCO score of 99.2%). From the assembled genome, in total protein coding, 5374 tRNA and 643 rRNA genes were annotated. We found that the D. arabica complete genome differed from those of other Daphnia species deposited in the NCBI database but was close to that of D. cf. similoides. However, its divergence time estimate sets D. arabica in the Mesozoic, and our demographic analysis showed a great reduction in its genetic diversity compared to other Daphnia species. Interestingly, the population expansion in its diversity occurred during the megadrought climate around 100 Ka ago, reflecting the adaptive feature of the species to arid and drought-affected environments. Moreover, the PFAM comparative analysis highlights the presence of the important domain SOSS complex subunit C in D. arabica, which is missing in all other studied species of Daphnia. This complex consists of a few subunits (A, B, C) working together to maintain the genome stability (i.e., promoting the reparation of DNA under stress). We propose that this domain could play a role in maintaining the fitness and survival of this species in the desert environment. The present study will pave the way for future research to identify the genes that were gained or lost in this species and identify which of these were key factors to its adaptation to the harsh desert environment.
Paradoxically, attention of experts on cladoceran biogeography is focused in Russia on the Arctic zone, Far East and Siberia, while Caucasus and Ciscaucasia are studied inadequately. The aim of this communication is to analyse the cladoceran fauna of lowlands of the Ciscaucasian Region to determine general regularities of their distribution, i.e. to reveal local biodiversity hotspots of the region. In total, 171 qualitative samples from 155 water bodies are
analysed where 57 species of Cladocera are recorded. All taxa are assigned to the following geographic faunistic complexes: (1) widely distributed Eurasian (WE), (2) southern tropical (ST), (3) Mediterranean-Ponto-Caspian endemic (EN), (4) arid (AR) complex; and two artificial groups: (5) widely distributed non-revised taxa (WS) and (6) eastern (possibly, anthropogenic)
invaders (IS). Distribution of faunistic complexes between two main biotopes in Taman and Other Ciscaucasia is significantly different: it is relatively similar for benthic + littoral (BP) species, but very different among the planktonic species (PL). Among PL species in the Taman sub-region, the portion of EN, IS and AR species is significantly higher and rate of WE and WS is significantly lower as compared to the Other Ciscaucasia. To date we have no explanation for such specificity of the Taman region. To date we cannot discuss the endemism hotspots of the Ciscaucasia and even Caucasus concerning the Cladocera, moreover, no one cladoceran taxon is regarded as an endemic of the Caucasus. The cladoceran studies need to be continued in this region.
