Land snail biogeography and endemism in south-eastern Africa: Implications for the Maputaland-Pondoland-Albany biodiversity hotspot

RESEARCH ARTICLE Land snail biogeography and endemism in south-eastern Africa: Implications for the Maputaland-Pondoland-Albany biodiversity hotspot Sandun J. PereraID1¤a*, David G. Herbert2¤b, Şerban Procheş1, Syd Ramdhani3 1 School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Durban, South Africa, 2 KwaZulu-Natal Museum, Pietermaritzburg, South Africa, 3 School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa ¤a Current address: Department of Natural Resources, Sabaragamuwa University, Belhuloya, Sri Lanka ¤b Current address: Department of Natural Sciences, National Museum Wales, Cardiff, United Kingdom * sandun.perera@appsc.sab.ac.lk, sandun.perera@gmail.com Abstract Invertebrates in general have long been underrepresented in studies on biodiversity, bioge- ography and conservation. Boundaries of biodiversity hotspots are often delimited intuitively based on floristic endemism and have seldom been empirically tested using actual species distributions, and especially invertebrates. Here we analyse the zoogeography of terrestrial malacofauna from south-eastern Africa (SEA), proposing the first mollusc-based numerical regionalisation for the area. We also discuss patterns and centres of land snail endemism, thence assessing the importance and the delimitation of the Maputaland-Pondoland-Albany (MPA) biodiversity hotspot for their conservation. An incidence matrix compiled for relatively well-collected lineages of land snails and slugs (73 taxa in twelve genera) in 40 a priori oper-

ational geographic units was subjected to (a) phenetic agglomerative hierarchical clustering using unweighted pair-group method with arithmetic means (UPGMA), (b) parsimony analy- sis of endemicity (PAE) and biotic element analysis (BEA). Fulfilling the primary objective of our study, the UPGMA dendrogram provided a hierarchical regionalisation and identified five centres of molluscan endemism for SEA, while the PAE confirmed six areas of ende- mism, also supported by the BEA. The regionalisation recovers a zoogeographic province similar to the MPA hotspot, but with a conspicuous westward extension into Knysna (towards the Cape). The MPA province, centres and areas of endemism, biotic elements as well as the spatial patterns of species richness and endemism, support the MPA hotspot, but suggest further extensions resulting in a greater MPA region of land snail endemism (also with a northward extension into sky islands—Soutpansberg and Wolkberg), similar to that noted for vertebrates. The greater MPA region provides a more robustly defined region of conservation concern, with centres of endemism serving as local conservation priorities. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0248040 March 4, 2021 1 / 26 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Perera SJ, Herbert DG, Procheş Ş, Ramdhani S (2021) Land snail biogeography and endemism in south-eastern Africa: Implications for the Maputaland-Pondoland-Albany biodiversity hotspot. PLoS ONE 16(3): e0248040. https://doi. org/10.1371/journal.pone.0248040

Editor: Geerat J. Vermeij, University of California, UNITED STATES Received: July 4, 2020 Accepted: February 18, 2021 Published: March 4, 2021 Copyright: © 2021 Perera et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: SJP was funded by the South African National Research Foundation (NRF; https://www. nrf.ac.za/) grants through ŞP (African Origins platform doctoral bursary, and incentive funding for rated researchers), a University of KwaZulu- Natal (UKZN; https://www.ukzn.ac.za/) doctoral research grant, Gay Langmuir bursaries for Conservation Biology (2010, 2012) and a UKZN