The Utilityof 28S rDNA for Barcoding of Freshwater Sponges (Porifera, Spongillida)

Sponges (Porifera, Spongillida) make up the bulk of the benthic biomass in Lake Baikal and are represented by the family Lubomirskiidae, a collection of endemic species, and several species of the cosmopolitan family Spongillidae. We conducted an analysis of the D3 domain of the 28S rDNA of 16 freshwater sponge species. Based on molecular data, we were able to identify all of the collected Spongillidae specimens whose identification was difficult due to the lack of gemmules. Phylogenetic trees have shown that Ephydatia muelleri, Spongilla lacustris, and Eunapius fragilis formed monophyletic clades, and the D3 domain of the 28S rDNA can be used for their DNA barcoding. For the Baikal sponges, the use of this marker is important since the gemmule-less Spongillidae and Lubomirskiidae are, in some cases, indistinguishable from each other in morphology. The 28S rDNA has been shown to be useful for family and species-level identification of freshwater sponges within the Spongillida.

Automated summary

This study analyzed the molecular data of 16 freshwater sponge species and found that the D3 domain of the 28S rDNA can be used for DNA barcoding of sponges. The use of this marker is important for distinguishing gemmule-less Spongillidae and Lubomirskiidae in Lake Baikal sponge species, which are difficult to differentiate morphologically.