Bryozoan statoblasts from lake sediments in Madagascar, including two new species
Abstract
Madagascar is a freshwater biodiversity hotspot, yet the current understanding of freshwater bryozoan diversity is limited. Using a dissecting microscope, bryozoan statoblasts were collected during macrofossil analysis of a sediment core, which was taken from Lake Sofia, Madagascar, in 2019. There was a peak in the abundance of statoblasts prior to 1900, with 67 statoblast valves found at 45.5 cm and a decline in more recent sediments. A subsample of 14 specimens was examined under a scanning electron microscope to determine species identification. One of the species found was Plumatella kinesis. Two new species, Plumatella tsimiheta sp. nov. and Plumatella sofiae sp. nov. were also found and described. These results show the potential of lake sedimentary bryozoan remains for categorising species presence and distribution. Although poor preservation was a limitation for identification, there is still value in having a historical record of past biodiversity, especially when species may no longer be extant. This study highlights the need for further research to better understand the status of these species and other potential new species of bryozoan in Madagascar.
References
Allman G.J. 1856. A monograph of the fresh-water Polyzoa, including all the known species, both British and foreign. Ray Society 28: 1–119. https://doi.org/10.5962/bhl.title.9143
Annandale N. 1909. Preliminary note on a new genus of Phylactolaematous polyzoa. Records of the Zoological Survey of India 3: 279–280. https://doi.org/10.26515/rzsi/v3/i3/1909/163283
Appleby P.G., Nolan P.J., Gifford D.W., Godfrey M.J., Oldfield F., Anderson N.J. & Battarbee R.W. 1986. 210Pb dating by low background gamma counting. Hydrobiologia 143: 21–27. https://doi.org/10.1007/BF00026640
Bamford A.J., Razafindrajao F., Young R.P. & Hilton G.M. 2017. Profound and pervasive degradation of Madagascar’s freshwater wetlands and links with biodiversity. PLOS One 12 (8): e0182673. https://doi.org/10.1371/journal.pone.0182673
Benstead J.P., De Rham P.H., Gattolliat J.-L., Gibon F.-M., Loiselle P.V., Sartori M., Sparks J.S. & Stiassny M.L. 2003. Conserving Madagascar’s freshwater biodiversity. BioScience 53 (11): 1101–1111. https://doi.org/10.1641/0006-3568(2003)053[1101:CMFB]2.0.CO;2
Birks H.H. 2001. Plant macrofossils. In: Smol J.P., Birks H.J.B., Last W.M., Bradley R.S. & Alverson K. (eds) Tracking Environmental Change Using Lake Sediments: Volume 3: Terrestrial, Algal, and Siliceous Indicators: 49–74. Springer Netherlands, Dordrecht. https://doi.org/10.1007/0-306-47668-1_4
Francis D.R. 2001. Bryozoan statoblasts. In: Smol J.P., Birks H.J.B. & Last W.M. (eds) Tracking Environmental Change Using Lake Sediments: Volume 4: Zoological Indicators: 105–123. Springer Netherlands, Dordrecht. https://doi.org/10.1007/0-306-47671-1_6
Hill S.L.L., Sayer C.D., Hammond P.M., Rimmer V.K., Davidson T.A., Hoare D.J., Burgess A. & Okamura B. 2007. Are rare species rare or just overlooked? Assessing the distribution of the freshwater bryozoan, Lophopus crystallinus. Biological Conservation 135 (2): 223–234. https://doi.org/10.1016/j.biocon.2006.10.023
Lamarck J.B.P.A. 1815. Histoire naturelle des Animaux sans Vertèbres... précédée d’une Introduction offrant la Détermination des Caracteres essentiels de l’Animal, sa Distinction du végétal et des autres Corps naturels, enfin, l’Exposition des Principes fondamentaux de la Zoologie. Verdière, Libraire, Paris. https://doi.org/10.5962/bhl.title.12712
Okamura B., Hartikainen H. & Trew J. 2019. Waterbird-mediated dispersal and freshwater biodiversity: general insights from bryozoans. Frontiers in Ecology and Evolution 7. https://doi.org/10.3389/fevo.2019.00029
Patmore I.R., Sayer C.D., Goldsmith B., Davidson T.A., Rawcliffe R. & Salgado J. 2014. Big Ben: a new wide-bore piston corer for multi-proxy palaeolimnology. Journal of Paleolimnology 51 (1): 79–86. https://doi.org/10.1007/s10933-013-9756-0
Pruvot Y.Z. & de Roland L.A.R. 2021. Food habits of the Malagasy Pond Heron (Ardeola idae) during the breeding season in northern Madagascar. Journal of Heron Biology and Conservation 6 (1): 2.
Wiebach F. 1964. Untersuchungen an Süsswasser-Bryozoen aus Zentralafrika. Annals de la Musée royal de l’Afrique centrale 129: 1–42.
Wood T.S. 2001. Plumatella mukaii, a new phylactolaemate bryozoan from Asia and South America. Hydrobiologia 445 (1): 51–56. https://doi.org/10.1023/A:1017526418685
Wood T.S. 2020. Review of freshwater Bryozoa (Phylactolaemata) of Central Africa with descriptions of two new species. Zootaxa 4820 (3): 581–600. https://doi.org/10.11646/zootaxa.4820.3.11
Wood T.S. 2022. Phylactolaemate bryozoans at the Zoological Survey of India and a taxonomic key to Indian Phylactolaemata. Zootaxa 5200 (5): 401–435. https://doi.org/10.11646/zootaxa.5200.5.1
Wood T. & Okamura B. 2005. The Freshwater Bryozoans of Britain, Ireland, and Continental Europe. Scientific Publication No, 63. Freshwater Biology Association of the United Kingdom, Swansholme, UK.
Copyright (c) 2023 Timothy S. Wood, Lilian Eva Unger, Laurence Rasoamihaingo
This work is licensed under a Creative Commons Attribution 4.0 International License.
Creative Commons Copyright Notices
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License (CC BY 4.0) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are NOT PERMITTED to post their submitted work online (e.g., in institutional repositories or on personal websites) prior to publication, as it may lead to nomenclatural issues.
