Filander Zoleka N, Sink Kerry J, Kitahara Marcelo V, Cairns Stephen D, Lombard Amanda T
Biodiversity and Coastal Research, Oceans and Coasts, Department of Forestry, Fisheries and Environment, Cape Town, South Africa.
Zoology Department, Nelson Mandela University, Gqeberha, South Africa.
PLoS One. 2024 Aug 8;19(8):e0296188. doi: 10.1371/journal.pone.0296188. eCollection 2024.
Azooxanthellate scleractinian corals, a group of species that lack a symbiotic relationship with dinoflagellates, are influenced by environmental variables at various scales. As the global commitment to sustainably manage ocean ecosystems and resources rises, there is a growing need to describe biodiversity trends in previously unsampled areas. Benthic invertebrate research in South Africa is a developing field, and many taxa in deep water environments remain inadequately characterized. Recently, the South African azooxanthellate scleractinian fauna was taxonomically reviewed, but their distributional correlations with physical parameters have not been studied. Here we aim to understand the biodiversity gradients of the South African azooxanthellate coral fauna by analysing the environmental correlates of museum samples. The associated coordinate data were georeferenced and depth obtained from a national bathymetric dataset, prior to undertaking a multivariate analysis. This analysis encompassed several steps, including the grouping of the longitude and depth data (environmental data), identifying families characteristic of the group variability, and examining the correlation of the associated data with the biological data. Additionally, the analysis involved quantifying diversity patterns along the environmental gradients. Overall, our results confirmed two longitudinal groups (eastern margin [Group A] vs southern and western margin [Group B]) and 11 depth categories represented within two bathymetric zones (shallow [50-200 m] and deep [300-1000 m]). Caryophylliids, flabellids, and dendrophylliids contributed the most towards distinguishing longitudinal and depth gradients. Both abiotic variable (longitudinal and depth) partially explained coral distribution patterns, with depth being highly correlated to the species variation observed. Data limitations within our data set resulted to unexplained variance, however, despite these limitations, the study demonstrates that historical museum samples provide a valuable data source that can fill research sampling gaps and help improve the understanding of biodiversity patterns of the coral fauna in under sampled marine ecosystems.
非虫黄藻石珊瑚是一类与鞭毛藻缺乏共生关系的物种，受到各种尺度环境变量的影响。随着全球对海洋生态系统和资源进行可持续管理的承诺增加，描述以前未采样地区生物多样性趋势的需求日益增长。南非底栖无脊椎动物研究是一个发展中的领域，许多深水环境中的分类单元仍未得到充分描述。最近，对南非非虫黄藻石珊瑚动物群进行了分类学综述，但尚未研究它们与物理参数的分布相关性。在这里，我们旨在通过分析博物馆样本的环境相关性来了解南非非虫黄藻珊瑚动物群的生物多样性梯度。在进行多变量分析之前，将相关的坐标数据进行地理参考，并从国家测深数据集中获取深度数据。该分析包括几个步骤，包括对经度和深度数据（环境数据）进行分组，识别该组变异性特征的科，并检查相关数据与生物数据之间的相关性。此外，该分析还涉及量化沿环境梯度的多样性模式。总体而言，我们的结果证实了两个纵向组（东部边缘[组A]与南部和西部边缘[组B]）以及两个测深带（浅[50 - 200米]和深[300 - 1000米]）内的11个深度类别。石芝珊瑚科、扇形珊瑚科和树珊瑚科对区分纵向和深度梯度贡献最大。非生物变量（纵向和深度）都部分解释了珊瑚分布模式，深度与观察到的物种变异高度相关。然而，我们数据集中的数据限制导致了无法解释的方差，尽管存在这些限制，但该研究表明，历史博物馆样本提供了一个有价值的数据源，可以填补研究采样空白，并有助于提高对未充分采样的海洋生态系统中珊瑚动物群生物多样性模式的理解。
