Partial revision of the neustonic genusScapholeberisSchoedler, 1858 (Crustacea: Cladocera): decoding of the barcoding results

Abstract

Water fleas (Crustacea: Cladocera) are among the most intensively studied freshwater invertebrates. However, ecologically important daphniids that live on the surface layer (neuston) remain taxonomically confused. Here we attempt to reconcile genetic and morphological information for the neustonic genus Scapholeberis Schoedler, 1858 (Cladocera: Daphniidae) and present the first revision of the Scapholeberis kingii species group. We analyzed new and existing mitochondrial DNA sequences (сytochrome C oxidase subunit I gene region) together with morphology for all but one of the known species of the neustonic daphniids. Morphological comparisons of available populations, belonging to the Scapholeberis kingii species group from several Australian, Asian and African localities, revealed, that they are almost identical according to parthenogenetic females. However, Australian populations can be reliably distinguished from Asian ones based on the morphology of gamogenetic females. Mitochondrial DNA data analyses revealed divergent lineages (>17% for the DNA barcoding COI region) for the three different species (Australia, Asia and Africa). Based on this set of data, we redescribed S. kingii Sars, 1888 from Australia, its terra typica, and described a new species, S. smirnovi sp.nov. from the Russian Far East, Korea and Japan. The status of populations from Ethiopia and the Republic of South Africa remained unclear, because in the African material and the putative type material, we found only parthenogenetic females. Our results provide an integrative revision of the S. kingii species group and improve the taxonomic scaffold used for barcoding and genomics for the remaining species groups in the daphniid genus Scapholeberis.

The species structure, biogeographical status, and the relation to the Beringian fauna of microcrustaceans (Cladocera, Copepoda) of the Magadan Area (Far East, Russia)

“…Species D. (D.) pulicaria is widespread in Eurasia and other continents; however, genetic studies have revealed [Crease et al, 2012] that this taxon is represented by a group of species that require detailed taxonomic revision. Scapholeberis microcephala is common in Scandinavia and European countries in the northwestern and central parts of European Russia up to the White Sea in the north [Garibian et al, 2020]. It is notable that the populations in Alaska and Sakhalin belong to another undescribed taxon [Taylor et al, 2020], our populations most probably also belong to it.…”

History of Colonization of Jeju Island (Republic of Korea) by the Water Fleas (Crustacea: Cladocera) Is Reflected by the Seasonal Changes in Their Fauna and Species Associations

“…Subsequent revisions could improve our ideas on exact biogeographic status of the taxa belonging to WS. However, in general, more detailed study usually leads to acceptance of a higher level of endemism as compared to a non-revised state [10,96]. The chance that further studies will demonstrate a significantly high representation of Boreal taxa on Jeju Island, compared to the present, is minimal.…”

DNA barcoding of crustacean larvae with two new records of Caridina gracilipes and Ptychognathus altimanus in the Western Region of Segara Anakan lagoon in Indonesia

“…It has been reported that monophyly with a short branch length can be used to determine the specimen's taxonomic status within a single clade (Xu et al 2015;Kusbiyanto et al 2020). Previous studies also used these parameters during species delineation based on molecular barcoding (Bekker et al 2016;Aguilar et al 2017;Nuryanto et al 2017;Lipinskaya et al 2018;Garibian et al 2020).…”