Investigation of the spongillid Spongilla alba Carter, 1849 reveals a new group of brackish-water sponges

Abstract

Freshwater sponges are widely distributed throughout the world, but their taxonomy and phylogenetics remain obscure. Studying distantly located specimens of the cosmopolitan spongillid Spongilla alba Carter, 1849, we revealed that these sponges differ from the rest of the studied Spongilla specimens by ITS1, ITS2, and COI sequences. Morphotraits of the sponges have a remarkable peculiarity compared with Spongilla genus: slightly fusiform slender microscleres with complex spines arranged in a pedunculate rosette at the middle and simple spines at the tips. Given both genetic and morphological differences, these sponges deserve being assigned to a new genus, Rosulaspongilla gen. nov. We found this genus to comprise two species that significantly differ in ITS sequences and have peculiarities in morphotraits. These sponges clearly prefer slightly brackish water, which highlights their independent status. Our result stresses the need to use an integrative approach in the investigation of freshwater sponges.

http://zoobank.org/urn:lsid:zoobank:org:pub:2B0A7FC0-35D7-474C-819E-2FE8D49B9B21

Key words:

• brackish water
• COI
• integrative taxonomy
• ITS1
• ITS2
• Porifera
• Spongillida

Acknowledgements

The work of AS was conducted under the IDB RAS GBRP no. 0088-2021-0020. The work of VI was supported by State Task no. 0279-2021-0011, by the Russian Foundation for Basic Research (RFBR) according to research project no. 20-04-00868 (DNA sequencing) and by RFBR and Department of Science and Technology (DST) according to research project no. 19-54-45034 (DNA sequencing). We thank Tom White and Jasmine Perera (Natural History Museum, London) for providing R. alba holotype and Allen Collins and Abigail Reft (Smithsonian National Museum of Natural History, Washington, D.C.) for providing numerous photos of the R. rhadinaea type sample. We are grateful to A.S. Saidov, G.G. Garibmamadov, N.M. Mirzoev, and L.S. Nabiev (Institute of Zoology and Parasitology, Academy of Science of the Republic of Tajikistan) who enabled our work in Tajikistan. The SEM work was performed at Electron Microscopy Centre of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Science and Borissak Palaeontological Institute of the Russian Academy of Science. We thank R. Rakitov for his assistance during SEM studies.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental material

Supplemental material for this article can be accessed here: https://doi.org/10.1080/14772000.2021.1958948.

Associate Editor: Ana Riesgo

Additional information

Funding

The work of AS was conducted under the IDB RAS GBRP no. 0088-2021-0020. The work of VI was supported by State Task no. 0279-2021-0011, by the Russian Foundation for Basic Research (RFBR) according to research project no. 20-04-00868 (DNA sequencing) and by RFBR and Department of Science and Technology (DST) according to research project no. 19-54-45034 (DNA sequencing). We thank Tom White and Jasmine Perera (Natural History Museum, London) for providing R. alba holotype and Allen Collins and Abigail Reft (Smithsonian National Museum of Natural History, Washington, D.C.) for providing numerous photos of the R. rhadinaea type sample. We are grateful to A.S. Saidov, G.G. Garibmamadov, N.M. Mirzoev, and L.S. Nabiev (Institute of Zoology and Parasitology, Academy of Science of the Republic of Tajikistan) who enabled our work in Tajikistan. The SEM work was performed at Electron Microscopy Centre of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Science and Borissak Palaeontological Institute of the Russian Academy of Science. We thank R. Rakitov for his assistance during SEM studies.