Browsing by Author "Samaai, Toufiek"

Now showing 1 - 8 of 8
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    Giants and titans: First records of the invasive acorn barnacles Megabalanus tintinnabulum (Linnaeus, 1758) and Megabalanus coccopoma (Darwin, 1854) on intertidal rocky shores of South Africa
    (Regional Euro-Asian Biological Invasions Centre (REABIC), 2022) Pfaff, Maya C.; Biccard, Aiden; Samaai, Toufiek
    During intertidal rocky shore surveys on the east coast of South Africa in 2018, the non-indigenous giant purple barnacle Megabalanus tintinnabulum (Linnaeus, 1758), a well-known fouling and globally-invasive species, was discovered. This motivated a survey of the entire South African east coast at 31 rocky shore sites, which confirmed that breeding populations of this barnacle have been established in most wave-exposed low-shore intertidal habitats between the Mozambique border and Mkambati Nature Reserve and that its current South African distribution spans 725 km of coastline. Another non-indigenous and common fouling species, the titan acorn barnacle M. coccopoma (Darwin, 1854), was discovered at three of the sites, its local distribution spanning 370 km of coastline. While currently uncommon, this species is known to reach high densities in other non-native regions. Both Megabalanus species are large and conspicuous and were not found during extensive surveys in the 1990s and early 2000s, suggesting that their introduction and spread occurred within the past two decades.
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    Heteroscleromorph demosponge taxonomy and diversity of the Amathole region (Eastern Cape, South Africa)
    (University of Western Cape, 2022) Payne, Robyn Pauline; Samaai, Toufiek
    Sponges are functionally important and ubiquitous components of the global marine benthos. South Africa accounts for roughly 4% of the global marine sponge diversity, comprising 374 described species and seven varieties/forms, with elevated apparent endemism (59.3%). However, an estimated 900 sponge species are thought to be undescribed, and much work is needed to update and expand our knowledge of the South African sponge fauna. The Amathole region is situated offshore of the Amathole District, around the city of East London, on the south-east coast of South Africa.
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    Kelp holdfasts in the Great African Seaforest provide habitat for diverse assemblages of macroinvertebrates
    (Inter-Research, 2024) Samaai, Toufiek; Katharoyan, Chaitanya; Peer, Nasreen
    Kelp forests along the southwestern and west coasts of South Africa, dominated by the species Ecklonia maxima and Laminaria pallida, are locally termed ‘the Great African Seaforest’. They form 3-dimensional biogenic habitats that provide 4 distinct microhabitats—canopy, fronds, stipe and holdfast—with the latter typically supporting the highest abundance and diversity of associated macroinvertebrates. The macrofauna inhabiting kelp holdfasts in South Africa have rarely been studied, resulting in a near complete lack of baseline data. In this study, macrobenthic assemblages from 40 E. maxima holdfasts were examined over 2 marine ecoregions and 4 locations. Macroinvertebrates were identified and counted for univariate and multivariate analyses using family-level data. A total of 120 families from 9 phyla were identified and were generally dominated by Arthropoda (48 families), Annelida (24 families) and Mollusca (23 families). Marine ecoregion had no significant effect on composition of macroinvertebrate assemblages, whereas location had a significant effect. There was no significant relationship between holdfast volume and macroinvertebrate diversity or abundance, suggesting that other environmental and physicochemical factors are important in determining community structure. This study serves as a baseline for future research aimed at understudied holdfast macroinvertebrate communities in the Great African Seaforest.
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    A revision of the genus Strongylodesma Lévi (Porifera: Demospongiae: Latrunculiidae) with descriptions of four new species
    (Cambridge University Press, 2009) Samaai, Toufiek; Gibbons, Mark J.; Kelly, Michelle
    The sponge genus Strongylodesma is reviewed and redefined, and now accommodates eight closely related species. The type species of Strongylodesma Le´vi is redescribed and an additional two new species are described from the Indo-Pacific: S. novaecaledoniae sp. nov. and S. tongaensis sp. nov. Several specimens previously identified as species of Batzella (Poecilosclerida: Chondropsidae) have been re-assigned to Strongylodesma, as the new species S. purpureus sp. nov. and S. nigra sp. nov. With the description here of new species from the Pacific Ocean and Caribbean Atlantic, the biogeographical distribution of Strongylodesma now appears to be generally tropical with a subtropical South African component, whereas previously it was only known from South Africa. Although species of Strongylodesma have not previously been recorded from the intermediate locations (Western Indian Ocean, South-east Asia, central west Pacific, and New Zealand), re-evaluation here will facilitate more readily the recognition of taxa in these intermediate regions, if they exist, in the future. The species are not widespread, except perhaps along the south-east coast of South Africa, and where they occur they are not abundant. Species occur over a wide depth range, from the intertidal in Tsitsikamma, South Africa, to 140 m in the Caribbean.
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    Stakeholder-derived recommendations and actions to support deep-reef conservation in the Western Indian Ocean
    (Wiley, 2022) Stefanoudis, Paris V.; Talma, Sheena; Samaai, Toufiek
    Deep reefs below 30mprovide essential ecosystem services for ocean health and human well-being such as food security and climate change resilience. Yet, deep reefs remain poorly researched and largely unprotected, including in the Western Indian Ocean (WIO). Here, we assessed current conservation approaches in the WIO focusing on deep reefs, using a combination of online surveys and semi-structured interviews. Results indicated that deep-reef data are sparse and commonly stemming from non-peer-reviewed or non-publicly available sources, and are often not used to inform conservation of WIO marine protected areas.
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    Studies on the diversity and spatial distribution of deep-water sponges along the west and south coasts of South Africa
    (University of the Western Cape, 2013) Maduray, Seshnee; Gibbons, M.J.; Samaai, Toufiek
    This thesis explores the diversity, spatial patterns and community structure for the sponges (Porifera) along the west and south coasts of South Africa. Species collected were identified to the lowest level of lowest taxonomic unit possible (either species or genus). The study site was divided into areas and in each of these we documented the spatial diversity and in so doing were able to assess the variation of sponge communities between the west and south coasts. The total number of species recorded for this deep-water region was eighty-three of which nineteen are described. The south coast was more diverse than the west coast and eleven species were found to be common to both coasts. The analysis based on location and depth showed that both coasts are significantly different to each other. We determined that these areas are biogeographically separated. Species contributing toward the dissimilarity between both coasts include Suberites carnosus, Myxilla (Burtonanchora) sp 1, Rossella antarctica, Tetilla capillosa and Haliclona sp. Patterns of species richness showed an increase in diversity from the west to south. It was found that species richness increases with depth for both coasts but only up to 350 m for the west coast and 200 m for the south coast. However, the sampling effort was determined to possibly have not been enough to gain a full understanding of species richness for the entire study area as the number of species was correlated with sampling effort. Estimated richness found that higher richness of sponges could still be found within most of the best bins and for each coast. An estimate of samples needed both each depth bin per coast showed that more samples would be needed on the south coast and this is possibly due to the greater variety and variability of the species found on the coast. The sponge community on the south coast was found to have no significant difference in pattern with some of the depth bins, whereas depth plays a role in sponge community on the west coast. Species of Suberites were dominant at depths lower than 200 m while Hamacantha (Vomerula) esperioides was dominant between 200 and 350 m with Tetilla capillosa dominated depths lower than 350 m. The thesis is concluded with an overview of what is now known and what still needs to be discovered and determined to further enhance biodiversity knowledge in the country.
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    Taxonomy and diversity of the sponge fauna from the Agulhas bank hard reef complex off the South African south coast
    (University of Western Cape, 2021) Weideman, Imogen; Samaai, Toufiek
    Hard benthic reefs are increasingly known as highly diverse biodiversity ecosystems where sponges constitute a significant proportion of inhabitants. Nearly 60% of the seabed over the inner and outer shelf on the Agulhas Bank comprises hard substrata, and in combination with the convergence of the cold Benguela and the warm Agulhas Currents serves to create a nutrient rich zone supporting multiple fish nurseries. Here we provide the first information on hard benthic reef habitats on the subphotic zone of the Agulhas Bank complex marine protected area, which include Alphard Banks, 72 Mile Reef and 45 Mile Reef, as well as the shallow reefs which include 12 Mile Reef, 6 Mile Reef, 7 Mile Reef, Marthas Reef and inshore reefs within the Tsitsikamma marine protected area. The aim is to provide baseline data on the sponge fauna by identifying species and describing the biodiversity of these hard reefs between the depths 10–200 m on the south coast of South Africa.
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    Taxonomy and diversity of the sponge fauna from Walters Shoal, a shallow seamount in the Western Indian Ocean region
    (University of the Western Cape, 2015) Payne, Robyn Pauline; Samaai, Toufiek; Gibbons, Mark. J; Florence, Wayne. K
    Seamounts are poorly understood ubiquitous undersea features, with less than 4% sampled for scientific purposes globally. Consequently, the fauna associated with seamounts in the Indian Ocean remains largely unknown, with less than 300 species recorded. One such feature within this region is Walters Shoal, a shallow seamount located on the South Madagascar Ridge, which is situated approximately 400 nautical miles south of Madagascar and 600 nautical miles east of South Africa. Even though it penetrates the euphotic zone (summit is 15 m below the sea surface) and is protected by the Southern Indian Ocean Deep-Sea Fishers Association, there is a paucity of biodiversity and oceanographic data. Thus, a multidisciplinary cruise was initiated in May 2014 on the FRS Algoa as a component of the African Coelacanth Ecosystem Programme. The research presented here focuses exclusively on the diversity, bathymetric distribution patterns and biogeographic affiliations of the sponge fauna of this seamount. Sponges were sampled using SCUBA and a roughed epibenthic sled, from the peak and down two opposing slopes of the seamount, to a depth of 500 m. Two hundred and fifty-five sponge specimens were collected, comprising 78 operational taxonomic units (OTU’s), 23 of which are known to science, 26 which are possibly new, 16 that could only be identified to higher taxonomic levels and 13 that could only be designated as morphospecies. Thirteen OTU’s are formally described here, four which are known, and nine possibly new to science. Sponge assemblages demonstrated no significant difference according to location on the shoal, with several species shared by both the western and eastern flanks. In contrast, sponge assemblages differed significantly according to depth, with the mesophotic zone (31 – 150 m) acting as a transition between the shallow (15 – 30 m) and submesophotic (> 150 m) zones. Species richness and the number of putative new species was highest in the submesophotic zone. Biogeographical affiliations were found with both the Western Indo-Pacific and Temperate Southern African realms based on the 23 known species recorded. No affiliations were found with the West Wind Drift Island Province, as has been documented previously for the fish fauna of this seamount, possibly due to the incomplete nature of the online database (World Porifera Database) used to assess affinities. Thirty-nine percent of the known sponge species found at Walters Shoal Seamount are widely distributed in the Indian Ocean, 35% are found exclusively within the Western Indian Ocean region, with this study representing the southernmost distribution record for several of these, and 26% have a restricted distribution around South Africa.