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Globally, South Africa ranks in the top five countries regarding marine species richness per unit area. Given the high diversity, it is not surprising that many invertebrate taxa in the region are poorly characterised. The South African azooxanthellate Scleractinia (Anthozoa) is one such taxonomic group, and was last reviewed by Boshoff in 1980. Although more recent regional publications have reported on some species, there has not been a faunistic review that accounts for the country's species diversity since then. Moreover, numerous unidentified specimens representing more than three decades of sampling effort have accumulated. In this study the authors update the state of knowledge of South African azooxanthellate coral species. Specimens, particularly those within the extensive collections of the Iziko South African and Smithsonian museums, were morphologically examined and identified. Other data considered included historic data represented as imagery data, associated species data from recent research surveys, and the scientific literature. To date, the study has increased the total number of known species from 77 to 108 across eleven families, 28 new South African records, and three are new species with one new genus. [ABSTRACT FROM AUTHOR]

Although the genus Halecium is easy to recognize, identifications at the species level are often difficult, this even for quite common and supposedly well-known species of the north-eastern Atlantic. This paper revises and re-describes some Halecium species which resemble each other closely and which are not easy to distinguish. Additional information on a few rare species is also provided. The study is based on material collected from the North Atlantic, Mediterranean, South Africa, and New Zealand. Halecium scutum Clark, 1877 is recognized as a valid species and distinct from both H. beanii and H. halecinum ; colony form and microscopic characters allow a distinction. The pinnate colony form of H. halecinum is a characteristic trait, but not all colonies show this growth form. Halecium beanii can occur in monosiphonic and polysiphonic colonies. Monosiphonic colonies of H. beanii have probably been misidentified by some authors as H. lankesterii . The differences of H. lankesteri to H. beanii and H. petrosum are discussed. The South African population of the reportedly cosmopolitan H. beanii has distinct gonothecae and could belong to a separate species. The Mediterranean Halecium mediterraneum is hardly distinguishable from the New Zealandic H. delicatulum , but it is kept separate mainly for biogeographic reasons. The rare Mediterranean Halecium banyulense is re-described based on a second find from Naples. The male gonothecae of Halecium corrugatissimum are described for the first time. [ABSTRACT FROM AUTHOR]

We have developed an algorithm to map benthic habitats on the continental shelf of South Africa, integrating marine geophysics and biological science. Multibeam bathymetry, backscatter and Remotely Operated Vehicle (ROV) footage were collected on the inner continental shelf of Cape St Francis and the hydroacoustic data were processed using machine learning clustering techniques. The k-means clustering algorithm was used to map the distribution of sediment at different depths. ROV footage was classified using the Collaborative and Automated Tools for Analysis of Marine Imagery (CATAMI) substrata classification scheme. Eight ROV dives along the three transects located off Seal Point, Cape St. Francis Point and within the bay were collected, and ranged from 30 to 80 m in depth. The most common Phyla in order from greatest to least abundance were; Cnidaria, Mollusca, Echinodermata, Chordata (fish species), Arthropoda (Subphylum Crustacea), Bryozoa, Porifera and Chordata (Class Ascidiacea), these were identified both on rocky substrate and sand. The first benthic habitat map of the Cape St. Francis area revealed ten different habitat types, accounting for geology, topography, and sediment cover. This work builds on an ongoing method development that incorporates broader habitat types from a range of substrates, enhancing the robustness of the algorithm, and will aid in improving our current understanding of the relationships between biota and physical habitats along the continental shelf of South Africa. • Multibeam bathymetry, backscatter and Remotely Operated Vehicle (ROV) footage were processed using machine learning clustering. • K-means clustering algorithm was used to map the distribution of sediment at different depths within the study area. • The ROV footage was classified using Collaborative and Automated Tools for Analysis of Marine Imagery (CATAMI). • The benthic habitat map of Cape St. Francis created using machine learning techniques revealed ten different habitat types. [ABSTRACT FROM AUTHOR]

Siphonophores have a widespread distribution in the world oceans, can be very abundant in some areas, and can have a significant impact on other pelagic animals. In this work, siphonophores from the Atlantic sector of the Southern Ocean were studied. Zooplankton organisms were collected at 35 stations in December 2009. Thirty different species were found: 2 physonects and 28 calycophorans. Total abundances of siphonophores varied with latitude; maximum numbers were observed in the northern part of the transect, in the vicinity of South Africa, where Muggiaea atlantica was the dominant species. To the south, the contribution of Eudoxoides spiralis and Lensia subtilis increased. In the whole investigated region, the most numerous siphonophore was Dimophyes arctica. Based on our results, it can be assumed that in the Atlantic sector of the Southern Ocean probably exist two Siphonophora biodiversity spots, probably exist in the Benguela Current region and the Subtropical Convergence region. Moreover, our results show that the Southern Subtropical Convergence seems to be a very strong biogeographical barrier for many tropical and temperate Siphonophora species. • There are three major areas in the Atlantic sector of the Southern Ocean occupied by different assemblages of siphonophores. • Some siphonophores previously recorded only in the specific regions of the Southern Ocean have broader distributions. • Southern Subtropical Convergence is a much more restrictive hydrological barrier than it was previously assumed. [ABSTRACT FROM AUTHOR]

Myxosporean parasites of the genus Kudoa are fish parasites of great economic importance, as some species can affect the fish fillet quality by producing macroscopic cysts or generating post mortem myoliquefaction, commonly referred to as 'soft flesh'. Kudoa mirabilis is a 'soft flesh'-inducing species originally described based on morphology in the musculature of Trichiurus lepturus from the Indian Ocean. An integrative morphological and genetic characterization of K. mirabilis from the type host caught off the coast of Tanzania is here provided. The spores were stellate with four unequal polar capsules, showing similarities to Kudoa thyrsites. For comparative and validation purpose, K. mirabilis was compared morphologically and genetically with K. thyrsites reference isolates, including new obtained samples from the type host Thyrsites atun caught in the SE Atlantic Ocean. Morphological analyses of spores revealed key diagnostic characters clearly distinguishing the two Kudoa species. Phylogenetic analyses based on SSU and LSU rRNA genes demonstrated that K. mirabilis is a distinct and valid species, representing a sister group to a K. thyrsites subclade that comprises several isolates from Japan and one single isolate from South Africa. This finding raises questions about the true diversity likely hidden in the K. thyrsites complex. [ABSTRACT FROM AUTHOR]