Molecular data are widely used to resolve complex phylogenetic relationships between cryptic species, particularly in cases where morphological features are insufficient to confirm taxonomic distinctness. For benthic shallow-water octopuses, several successes and failures have been reported when attempting to delineate species using individual nuclear or mitochondrial markers. In this study, we investigated the potential of shallow random shotgun sequencing to assess the phylogenetic placement of an undescribed southern hemisphere lineage within the Octopus vulgaris species complex, which could not be conclusively delimited using single-marker approaches. A total of 338 nuclear loci, along with complete mitochondrial genomes, were generated for two specimens presently classified as Octopus vulgaris (Type III) that originated from the southeastern Atlantic coast of South Africa and Amsterdam Island in the southern Indian Ocean. Our combined phylogenomic approach reveals that this lineage is genetically distinct from O. vulgaris sensu stricto (ss) from the Mediterranean and the northeast Atlantic, as well as from the closely related O. sinensis from East Asia. A further separation of O. vulgaris (Type III) into distinct South African and Amsterdam Island lineages cannot be proven. These findings add to the growing body of evidence that supports O. vulgaris Type III as a genetically distinct lineage within the O. vulgaris species complex, and emphasise that the taxonomic classification of this southern hemisphere lineage warrants re-evaluation.

Kelp forests are among the most extensive and productive coastal ecosystems, yet they remain underrepresented in global conservation policy despite widespread declines driven by interacting global- (i.e., ocean warming, marine heatwaves) to local-scale stressors. At the same time, kelp conservation and restoration efforts are expanding rapidly across regions, but measures of success and syntheses tend to primarily focus on ecological conditions and trends, not on conservation and restoration actions. To fill this gap, we developed a comparative global dataset of kelp conservation initiatives based on expert-derived regional narratives from 209 participants spanning 35 regions with kelp forests. We applied a structured presence–absence scoring framework across six domains: conservation actions, restoration approaches, governance actors, conservation objectives, social dimensions, and funding structures, supplemented by regional expert knowledge to enable cross-regional comparison. Across regions, conservation was characterised by strong emphasis on monitoring (86

The conservation of biodiversity is fundamental for the persistence of ecosystems, particularly under climate change. The South African marine environment is characterized by high levels of biodiversity as well as endemism, but species distribution patterns are generally not well characterized. Environmental DNA (eDNA) metabarcoding is a promising tool to help plug the biodiversity information gap, but evidence from previous studies has shown highly variable eDNA signals, even at small temporal-spatial scales (< 300 m, 24 h). Passive samplers, deployed over several hours may circumvent some of the challenges of high eDNA variation by accumulating DNA over time. Using multiple markers (mtDNA 12S rRNA, mtDNA COI), we test both active (using Sterivex) and passive sampling (gauze filled metaprobe) in the detection of kelp forest-associated biodiversity, focussing on fishes and invertebrates. We conducted our experiment across different time periods (6, 12, 24 h) and hypothesized that metaprobes at 24 h would harbor the greatest species richness. We detected 33 ESVs, assigned to 18 different fish families, with 12S rRNA, where active sampling retrieved a larger proportion of diversity (94% vs. 64%, p < 0.001). For COI, we detected 1481 ESVs assigned to 17 different phyla, 99 families, and 55 species, with passive sampling detecting more ESVs (82% vs. 67%, p < 0.001). COI metabarcoding detected an additional four families of fishes, highlighting the importance of multi-marker approaches. For passive sampling only, there was a trend of significant accumulation of numbers of reads and ESVs over time. We found that active samples were more consistent across all statistics: variation in the number of reads, ESVs, and taxa retrieved, which was less in active than passive replicates. Overall, we highlight the need for region-specific approaches and careful project planning before implementing eDNA metabarcoding as a biomonitoring tool.

Mantis shrimps are important predatory crustaceans in the marine benthos and comprise some 500 described species worldwide, the majority inhabiting the tropics, with a few found in temperate regions. However, current taxonomic knowledge of the mantis shrimp fauna of South Africa is limited and outdated, with the last comprehensive taxonomic revision of the group being that of K.H. Barnard in 1950. The stomatopod crustaceans of South Africa are reported based on previous records in the literature and existing material housed in the Iziko South African Museum, Cape Town. Five species are added as new records for the region including an undescribed species of Gonodactylus, increasing the number of South African stomatopods from 26 to 31 species belonging to 20 genera from nine families. Notable findings include high variation in genus- and species-diagnostic features of Pterygosquilla capensis, such as rounded ocular scales and more than 18 SM denticles of the telson. Taxonomic species accounts of all known national species are compiled to present the first comprehensive and fully illustrated identification guide of the stomatopods from South African waters.

Aim: The biodiversity associated with kelp forest ecosystems is understudied globally, including in South Africa, where kelp forests have expanded their range under climate change. This study used environmental DNA (eDNA) metabarcoding to assess fish biodiversity across an expansive range (similar to 1000 km) of South Africa's kelp forests, contributing to a contemporary fish biodiversity baseline. We examined whether this baseline reflects existing biogeographical patterns, including the leading edge of an expanding kelp forest. Location: South Africa. Methods: We conducted eDNA metabarcoding, targeting the mitochondrial 12S rRNA gene for fishes, on 192 aquatic eDNA samples collected at eight sites spanning two ecoregions (Southern Benguela and Agulhas) and three kelp forest types (Namaqua, Cape and Agulhas). Intra-site spatiotemporal samples were collected to capture variability in eDNA signals at small spatial (< 600 m) and temporal (similar to 24 h) scales. Results: In total 140 operational taxonomic units (OTUs) from 39 marine fish families were detected, with 40 OTUs resolved to genus and 25 to species, encompassing a wide range of functional groups. OTU richness increased from west to east and differed significantly (p < 0.05) between ecoregions. Communities were significantly different (p < 0.05) across all biogeographical and intra-site predictors. While OTU accumulation curves did not fully saturate, spatiotemporal sampling at sites with lower species richness captured a larger proportion of extrapolated diversity. Notably, De Hoop, located at the kelp forest's leading edge, exhibited particularly distinct community patterns. Main Conclusions: This research demonstrates that eDNA metabarcoding effectively detects diverse fish communities in a marine biodiversity and climate change hotspot, revealing biogeographic and local structuring patterns. However, gaps in the 12S reference database limit taxonomic resolution, highlighting the need to expand reference sequences. Continued development of eDNA metabarcoding across a range of spatiotemporal scales will enhance our understanding of biodiversity dynamics in South Africa's coastal ecosystems.

Gastropods of the echinoderm-parasitic family Eulimidae show extraordinarily high ecological diversity. A combination of the three types of parasitism (temporary, ecto- and endoparasitism) and the five classes of extant Echinodermata allows us to identify 15 potential categories of parasitic association, all but 1 of which have already been documented. Here, we describe the last remaining category by recording the first endoparasitic eulimid in the Ophiuroidea, Introphiuricola rebeccae n. gen., n. sp., from the bursal sac of the brooding brittle star Amphiura capensis (Amphiuridae) in Cape Town, South Africa. This new eulimid is characterized by (1) a globose pyriform shell up to 1.8 mm high with a blunt apex; (2) large body whorl occupying >= 90% of the total shell height; (3) large, drop-shaped aperture with a simple prosocline outer lip; (4) brownish, dorsoventrally depressed pupiform protoconch; (5) large epipodial flap on either side of the foot; (6) endoparasitic mode of life in an ophiuroid; (7) probable protandrous sequential hermaphroditism; and (8) direct early development with no pelagic larval period. A molecular phylogenetic reconstruction reveals its close relationship to certain temporary parasites of ophiuroids with slender shells in the genera Helimiostraca, Eulima and Pyramidelloides. Its distant relationship to Stilifer, a group that also has a globose shell and lives inside asteroids, suggests an independent endoparasitic origin of the globose shape for different hosts. Benthic early development shared by the present ophiuroid and eulimid implies that this host-parasite interaction has arisen locally and remains endemic to South Africa and perhaps also Mozambique.

The Galeommatoidea are a diverse but little-studied group of small bivalves, well known for the symbiotic relationships many species have with a range of invertebrate taxa. Four species collected from the Western Cape region of South Africa were examined and illustrated, providing new details on their habitat preferences, and depicting the mantle structure of live specimens for the first time. Brachiomya ducentiunussp. nov., is described herein, and an additional record of Montacuta substriata (Montagu, 1808) is reported from South Africa. Brachiomya ducentiunus and Montacuta substriata have obligate symbiotic relationships with different burrowing echinoids, while Kellia becki (WH Turton, 1932) and Melliteryx mactroides (Hanley, 1857) are free-living. DNA data and phylogenetic analyses are provided for three of the species.

From June to September 2022, five colonies of the rare hydrozoan siphonophore Rhizophysa eysenhardtii were observed for the first time near the surface in False Bay, South Africa. The two colonies in June/July were small with all tentacles contracted, while the September colonies were larger, the largest up to 0.8 m long (in video), with most of its tentacles extended for feeding. In this species, tentacles are typically pink and each arises from the proximal end of a gastrozooid, which engulfs and digests the prey. Fish larvae were noted in the gastrozooids and counted and a chaetognath was observed stuck to one of the tentacles. The pneumatophore was prominent in all specimens and gonodendra bearing sexual gonophores were visible between the gastrozooids of the larger specimens.

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.

ABSTRACTEnvironmental DNA (eDNA) metabarcoding surveys can support the acquisition of extensive biodiversity data to support ecosystem monitoring and conservation actions. However, the optimization of eDNA metabarcoding project design is essential to capture spatio‐temporal heterogeneity of eDNA signals and maximize diversity detection. In this study, we developed a system‐specific approach to detect fish communities in kelp forests, by analyzing fine‐scale spatio‐temporal patterns in eDNA signals at two sites along the South African coastline, as well as testing the effect of biological replication and pooling of replicates on species detection. At each site, samples were collected at two stations along the shoreline at two depth zones, and this was repeated at two time points (24 h apart). We detected 113 operational taxonomic units (OTUs) across 32 families, but fewer than 20% of OTUs could be assigned to species, indicating that barcode reference libraries need to be drastically improved. We detected significant differences in communities across small spatial scales (< 600 m) and time points, suggesting that to best capture a site's diversity patterns, samples should be collected at multiple points and times within at least 24 h. To detect ~80% of the fish community, including some low abundance species, a minimum of four samples appear sufficient. In addition, a higher number of OTUs (76 vs. 65) were found in individual replicates than in any of the pools. However, pooling samples prior to sequencing can still detect valuable broad‐scale biodiversity patterns for monitoring and can offset the decrease in data resolution with the benefit of accumulating comprehensive data from increased sampling efforts over time. As a pilot investigation into how best to maximize kelp forest‐associated fish communities, this study provides a basis for optimizing sampling design for coastal eDNA‐based surveys in southern Africa and strengthens the development of long‐term eDNA monitoring programs to better support conservation and management actions.

The rare diogenid hermit crab Cancellus makrothrix Stebbing, 1924, previously known from only a few specimens collected a century ago from Algoa Bay, South Africa, has been found to be common in the kelp forest known as the "Great African Seaforest", and rocky reefs, of False Bay, South Africa. This poorly known species, considered "aberrant" by some carcinologists, is one of 17 known in the genus Cancellus H. Milne Edwards, 1836, and the only of the genus known to occur in the coast of southern Africa. Cancelllus makrothrix lives in gastropod shells, whereas all other congenerics live in a variety of petricolous dwellings that are either excavated or worn away into cylindrical cavities. The newly collected material of C. makrothrix in South Africa, together with the study of historical museum specimens has made possible the detailed redescription and taxonomic discussion of this species presented herein, using full illustrations, photographs, and microCT scans. For future reference, the molecular CO1 genetic barcode is reported. A lectotype is selected from Stebbing's original syntype material found to consist of two specimens: a female of which only several appendages remain, in the Natural History Museum, London, and a male, illustrated in the original description, in the Iziko South African Museum, Cape Town. Taxonomic remarks, comments on biological oddities, brief in situ and laboratory observations of live specimens, and a map summarizing the world distribution of species of Cancellus, , are included.

A new hermit crab-sponge association is reported from soft-bottom sediment at 35-50 m depth in St Francis Bay, off the south coast of South Africa, and the associated sponge, Suberites ambulodomus sp. nov. (Suberitida, Suberitidae), is described as a species that is new to science. This species grows a spirally curved chamber occupied by the hermit crab Pagurus liochele. Suberites ambulodomus sp. nov. differs from congeners in southern Africa by having tylostrongyle megascleres (in addition to tylostyles) and smooth centrotylote microstrongyle microscleres. In addition to these morphological characters, the molecular marker cox1 was used to confirm that all collected specimens were conspecific, and distinct from the recently described S. dandelenae Samaai et al., 2017 from South Africa's west coast. This is the first report of a sponge-hermit crab association in southern Africa, which is suggested to be facultatively mutualistic. http://zoobank.org/urn:lsid:zoobank.org:pub:D6C2BAC9-7F30-4CE4-908E-17FB9B8F5102

Environmental DNA (eDNA) metabarcoding is a promising tool for monitoring marine biodiversity, but remains underutilised in Africa. In this study, we evaluated the ability of aquatic eDNA metabarcoding as a tool for detecting biodiversity associated with a South African kelp forest, an ecosystem that harbours high diversity of species, many of which are endemic, but are also sensitive to changing environmental conditions and anthropogenic pressures. Using fine-scale spatial (1 m and 8 m) and temporal (every four hours for 24 h) sampling of aquatic environmental DNA and targeting two gene regions (mtDNA COI and 12S rRNA), metabarcoding detected 880 OTUs representing 75 families in the broader metazoan community with 44 OTUs representing 24 fish families. We show extensive variability in the eDNA signal across space and time and did not recover significant spatio-temporal structure in OTU richness and community assemblages. Metabarcoding detected a broad range of taxonomic groups, including arthropods, ascidians, cnidarians, echinoderms, ctenophores, molluscs, polychaetes, ichthyofauna and sponges, as well as Placozoa, previously not reported from South Africa. Fewer than 3% of OTUs could be identified to species level using available databases (COI = 19 OTUs, 12S = 11 OTUs). Our study emphasizes that kelp-forest associated biodiversity in South Africa is understudied, but that with careful consideration for sampling design in combination with increased barcoding efforts and the construction of regional databases, eDNA metabarcoding will become a powerful biomonitoring tool of kelp-forest associated biodiversity.

Abstract Environmental DNA metabarcoding is a powerful tool for monitoring marine biodiversity, yet several outstanding questions remain regarding the persistence of eDNA. In this study, we use fine-scale spatial (1 m, 8 m) and temporal sampling (every four hours for 24 hours), in combination with metabarcoding to test the effect of depth and time on community assemblages in a dynamic kelp forest ecosystem, specifically to enhance our understanding of sampling regimes. Using mtDNA COI and 12S rRNA, metabarcoding detected 880 OTUs representing 75 families in the broader eukaryotic community and 44 OTUs representing 24 fish families. Only a few OTUs (COI = 19, 12S = 11) could be assigned to species. No significant depth or time partitioning of OTU assemblages was found, likely reflecting high levels of eDNA transport, with community composition and OTU richness not significantly different across depth over the 24 hour sampling period. Together with incomplete barcoding reference databases, results indicate that understanding the fine-scale spatio-temporal dynamics of eDNA signatures is crucial for informing sampling strategies and interpreting the dynamics of aquatic communities. Finally, our study emphasizes how understudied South African kelp forest systems are, and the potential eDNA metabarcoding holds for documenting their high levels of biodiversity.

Octopus vulgaris type III preys upon molluscs by drilling a hole in the shell, through which it injects venom, weakening the muscles and allowing the octopus to remove and eat the mollusc flesh. In False Bay, South Africa, the abalone Haliotis midae, the kelp limpet Cymbula compressa and the helmet snail Semicassis zeylanica, are all common octopus prey, but each has a very different shell morphology and underlying anatomy. It is hypothesized that O. vulgaris type III targets the muscle attachment site of all three species and that the precision of drilling should correlate with the relative size of these muscle attachment sites. Measurements of the locations of drill holes from collected shells of each species showed that drilling locations were significantly non-random. In the abalone and limpet, the muscle attachment site was targeted two and 4.5 times more frequently than expected, respectively. Octopus vulgaris type III drilled helmet snails with extreme precision, with over half the holes drilled on the spire at an angle of 45° and 90° from the lip. Kernel density heat maps demonstrated that octopus drilled abalone with low precision, limpets with medium precision and helmet snails with high precision. The reason for the high precision in the helmet snail remains speculative, as the main drilling location did not align with the columellar muscle attachment and no target could be defined. This study is the first to assess octopus drilling in temperate southern Africa and to compare drilling precision across different prey species.

New and notable stomatopods are reported on and added to the Mozambican faunal list, based principally on material housed in the collections of the Iziko South African Museum. Seven species are reported for the first time from Mozambican waters including one undescribed species of Clorida Eydoux & Souleyet, 1842, bringing the total known Mozambican stomatopod fauna to 22 species, comprising 17 genera and eight families. The known fauna is tabulated and taxonomic accounts of eight species are given, seven of these representing the new species records including one undescribed species, while the eighth species account is of the previously poorly documented Erugosquilla woodmasoni (Kemp, 1911), which is reported on from unpublished material. The new record of Manningia australiensis Manning, 1970 represents the first record of the family Eurysquillidae from southern Africa.

The recently described amphipod Sunamphitoe roberta lives only on the kelp Ecklonia maxima, where it excavates slit-like burrows along the distal margins of thicker primary fronds. Oval chambers along the bases of these slits may represent feeding areas. As burrowing proceeds, the damage progressively erodes back the frond margins, giving them characteristic attenuated and irregular profiles, and probably impacting secondary frond survival and growth, and hence kelp productivity. A kelp forest in False Bay, South Africa, was surveyed to determine what proportion of kelp was infected as well as which individuals were selected as hosts. Forty kelp heads were also dissected to ascertain numbers of amphipods per host and their size composition, and to document details of burrow structure. Of 305 adult kelps inspected, 117 (38.4%) showed visible amphipod damage. Rate of infestation was not correlated with stipe length but was positively correlated with head circumference and negatively correlated with the proportion of secondary fronds remaining. The 40 kelp heads dissected contained 786 S. roberta specimens. These comprised 154 adults (>8 mm), including 33 ovigerous females, and 632 juveniles (<8 mm). The number of amphipods per host ranged from 1 to 112 (mean 19.7 [SD 25.1]). Size distribution was bimodal, and the largest individual measured 20 mm.

This report adds five previously unreported species to the decapod crustacean fauna of South Africa, as well as removing one species previously listed in error. It also documents locality (and/or reference specimen) data for 12 other species, most of which had been depicted in regional field guides, but without reporting when and where they had been collected. Almost all the species added were already known from adjacent African countries and their ranges are here extended into South Africa. Although some of these records are based on photographs, rather than collected specimens, it is argued that such records should be accepted as adequate evidence for inclusion of at least visually-distinctive crustacean species into the regional fauna.