Biodiversity and distribution of the southern African sea cucumbers (Echinodermata: Holothuroidea)

Abstract

The history of the southern African holothuroid fauna south of the tropic of Capricorn, is updated and the biodiversity and distribution of the fauna discussed. All five currently recognized orders are represented, distributed over 24 families, 74 genera and 163 species. As many as 117 species are shelf forms comprising the following faunistic components : 36% Indo-Pacific, 12% West Indian Ocean, 1% Atlantic and 51% endemic. Four faunistic provinces are recognized : tropical Indo-Pacific Province on the east coast, extending to St Lucia in northern KwaZulu-Natal; the Subtropical (Natal) province, from this point to Port St. Johns in the Eastern Cape Province; the Warm Temperate (Agulhas) Province from this point to Cape Point in the Western Cape Province; and the Cold Temperate (Namaqua) from Cape Point to Walvis Bay in Namibia. Vertical distribution of the approximately 90 species collected from more than one locality is also given. The origin of the holothuroid fauna is briefly discussed and reiterated that the Indo-Pacific component moved in from the north mostly by way of the Mozambique-Agulhas Current. The origin of the endemic component is obscure but surmised that it is perhaps also of Indo-Pacific origin with negligible contribution from the Atlantic.

An Estuary Ecosystem Classification that encompasses biogeography and a high diversity of types in support of protection and management

“…In contrast, to the south, St Lucia Estuary supports invertebrate and fish assemblages common in Subtropical estuaries on the subcontinent (MacKay et al 2010;Perissinotto et al 2013). The new zone also aligns with marine biogeographic patterns evident for floral and faunal groups, such as benthic macroalgae (Bolton et al 2004), intertidal invertebrates and algae (Sink et al 2005), and shelf holothuroideans (Thandar 2015), and agrees with the recent marine biogeographic map that includes the Natal-Delagoa tropical region (Sink et al 2019).…”

“…Ecosystem-level classification schemes have a wide range of potential application in research and natural resource management. National and regional ecosystem classifications are useful, because they can be applied to the International Union for Conservation of Nature (IUCN) Red List of Ecosystems (RLE) framework to assess risks and identify vulnerable ecosystems based on a set of criteria and thresholds (Rodríguez et al 2011;Keith et al 2013;2015;Bland et al 2017aBland et al , 2017bBland et al , 2018.The RLE requires clearly defined units of assessment (ecosystem types) that can be spatially delineated (Keith et al 2013). Ecosystem classification is therefore one of the fundamental inputs for such global assessment processes.…”

Barcoding (COI) Sea Cucumber Holothuria mammata Distribution Analysis: Adriatic Rare or Common Species?

“…Sea cucumbers are a traditional delicacy in many Asian countries, including Singapore, Korea, Taiwan, and Hong Kong [1]. Due to overharvesting and stock depletion of these organisms in most of the world's traditional fisheries, there has been a recent expansion of the industry into temperate regions where sea cucumbers have little economic value in local cultures [2][3][4]. The Mediterranean Sea is among the least harvested regions of the world, with Turkey leading the industry with over 500 tons harvested per year [5,6].…”