Urban sprawl can fundamentally alter local biodiversity, resulting in food web shifts. Consequently, one would expect organisms living in peri-urban areas to experience a functional dietary shift compared to their counterparts inhabiting natural habitats. Here, the diets of two dwarf chameleon species, Bradypodion damaranum and B. ventrale, were assessed using eDNA metabarcoding of faecal material. Both species have well established peri-urban and natural populations, making them well suited for dietary comparisons. Assuming prey assemblages differ between natural and peri-urban areas, chameleons may have enough flexibility to take advantage of new prey resources. This would be reflected in corresponding differences in dietary composition. Two primer combinations amplifying portions of the mitochondrial COI gene, mlCOIintF/jgHCO2198 (universal) and ZBJ-ArtF1c/ZBJ-ArtR2c (arthropod-specific), were used to explore their diets. A total of 40 arthropod prey species and one nematode species were identified from 22 chameleon individuals. The mlCOIintF/jgHCO2198 primers produced a greater number of taxonomic identifications, whereas the ZBJ-ArtF1c/ZBJ-ArtR2c primers identified rarer taxa, with limited taxonomic overlap between primer sets. This suggests that combining multiple primer sets will enhance diversity exploration in future studies, however, relative costs have to be balanced with intended outcomes. Three major soft-bodied insect orders (Neuroptera, Thysanoptera, and Trichoptera) were identified in the dwarf chameleon diets. No significant differences in the composition of prey items were found between peri-urban and natural populations of B. damaranum. A relative abundance of lepidopterans was found in peri-urban B. ventrale populations, however, other prey items remained consistent between populations. Overall, our findings suggest that prey items consumed by the peri-urban population are not overtly different to their natural counterparts.

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.

The Cape sea urchin, Parechinus angulosus, is a widely distributed keystone species that inhabits intertidal and subtidal ecosystems along the South African coastline. Despite its importance as an ecosystem engineer, its phylogenetic placement and mitochondrial genomic (hereafter mitogenome) variation remain poorly understood. In the current study, we present the first complete mitogenome for this species, assembled from long-read sequences generated on the Oxford Nanopore sequencing platform, and investigate its phylogenetic placement among other sea urchin species using a combination of Bayesian Inference and Maximum-Likelihood methods. A circular genome of 15 722 bp, with an average coverage of 159, comprising 13 protein-coding genes, two rRNAs and 22 tRNAs, was assembled de novo. Phylogenetic reconstructions based on 13 protein-coding genes recovered Paracentrotus lividus as the sister taxon of P. angulosus, and these two species formed a monophyletic clade with Loxechinus albus and Sterechinus neumayeri within Camaradont sea urchins. Using the mitogenome assembly as a template, an additional set of 29 cox1 sequences was mined from publicly available genomic sequences. These revealed that Cape sea urchins maintain substantial mitogenomic variation across their distribution range, expressed predominantly as low-frequency haplotypes. This study demonstrates that the Cape sea urchin is genetically distinct within the order Camarodonta and exhibits considerable variation in the cox1 gene across coastal habitats of southern Africa. Furthermore, the identification of a large number of low-frequency haplotypes may indicate population expansion or ongoing purifying selection.

Hymenosoma Desmarest, 1823 is here confined to seven species from southern Africa and Madagascar, one described herein, Hymenosoma luriosp. nov. from Mozambique. Hymenosoma luriosp. nov. is unique in having the male posterior thoracic lobes oval with a short stalk. Evolutionary relationships between the new species and five other species of Hymenosoma are reconstructed from sequences of the COI gene, and another tropical species, H. projectum Dawson & Griffiths, 2012, is identified as the sister taxon. Each species is diagnosed and a key to differentiate them is given. Three species of Hymenosoma described from New Zealand and Australia are excluded from this genus.

Substantial disparities in research excellence exist between scientists, which are largely explained by the considerable influence of elite institutions and the resources available to them. Cumulative advantage has become a dominant force behind social stratification in science, increasing the tendency of researchers to monopolize the resources in their field. In the biological sciences, many researchers are drawn to 'charismatic' study species, which can increase their exposure and status in academia. In this study, we shed light on research monopolization and academic exclusion, and assess how these are influenced by charismatic species and a researcher's social group. We applied bibliometric methods (comparing 800 scientific papers on charismatic vs. non-charismatic species), survey-based methods (of 826 respondents) and network analysis. We found positive correlations between species' charisma and both the impact and volume of scientific output and the frequency of international collaborations. We also found that the participation of researchers from 'non-native countries' was significantly higher when charismatic species were being studied, which mainly applied to researchers from universities in North America and Europe studying charismatic species in Africa, South America and Asia, but hardly ever the other way around. Charismatic species increased negative workplace experiences and enhanced encounters with research monopolization, which 46% of all survey respondents who worked on such species claimed to have experienced. Academic exclusion was strongly linked to social group membership, particularly to the detriment of female and less experienced scientists. Awareness of the problematic behaviours highlighted in this study may contribute towards ensuring that the career trajectories of biological scientists will benefit from more equal opportunities.Read the free for this article on the Journal blog.

Coastlines are a mosaic of habitats, including rocky shores, sandy beaches, estuaries, and artificial substrata. Although modern microbialite pool formations were only recently discovered as an additional coastal habitat along the southern African coastline, they are now known to be surprisingly common to this region. These ecosystems function similarly to estuaries, where seawater and freshwater mix, but with groundwater as the freshwater source instead of river flow. Traditional community assessments from morphological identifications have revealed some similarities between the organisms inhabiting microbialite pools to those of nearby estuaries, but no systematic comparison has so far been undertaken. Here, we used molecular methods based on environmental DNA (eDNA) metabarcoding to characterise the eukaryote assemblages within and between three coastal southern African microbialite pools. We hypothesised that the three sites are taxonomically analogous to one another, which would support the existence of similar core ecological communities. Three genetic markers, one for metazoans (COI) and two for algae (rbcL and the V2+V3 regions of 18S rRNA) were targeted for metabarcoding. Our results show that the biodiversity of the pools was dominated by diatoms (particularly of the genera Navicula and Nitzschia) and, among the metazoans, by malacostracans, rotifers and nematodes. Although the three microbialite pools had similar broadscale community compositions at higher taxonomic levels (class and family), distinct community structure at lower taxonomic levels was observed, which may be a result of numerous opportunistic species being present in addition to the core organisms. The macroinvertebrate fauna of microbialite pools (e.g. peracarid crustaceans, polychaetes and insects) is well documented, although most are still missing from the DNA barcoding reference library. In contrast, the meiofauna (e.g. rotifers, nematodes and ostracods) is understudied. It remains unclear whether the two dominant diatom genera are the primary contributors to microbialite formation, or if other yet-undescribed species also contribute to the process. This study serves as an initial step in uncovering the hidden level of biodiversity within the unique microbialite ecosystems along the southern African coastline.

Marine bacteria are the dominant biomass in the oceans. Diverse microbial communities have colonised different organs in various life forms, and their genetic diversity, and biochemical functions they perform, play a critical role in an organism's fitness and ecosystem status. The study of gut microbiota in marine organisms has gained increasing attention due to the critical role of gut bacteria in host digestion, nutrient metabolism and immune function. The Cape sea urchin, Parechinus angulosus, is the most widely distributed echinoid along southern Africa's coastline and inhabits coastal regions with contrasting oceanic physico-chemical features. The diversity of the gut-associated bacteria, spatial compositional variation across its distribution range, and the connection between host genomic diversity and gut microbiota are currently unknown. This study used a combination of 16S rRNA metabarcoding and ezRAD sequencing of host genomes to describe the diversity in Cape sea urchin and its associated gut microbiota. Bacterial taxa belonging to 20 phyla, 39 classes, 89 orders, 128 families and 191 genera were identified. While alpha diversity did not vary significantly within the bioregions inhabited by the sea urchin (west coast and south coast), beta diversity indices revealed significant differences in bacterial community composition between individuals collected from the two bioregions. A distance decay analysis indicated a statistically significant correlation between geographical distance and dissimilarity in bacterial assemblage throughout the distributional range. Genomic analysis revealed no statistically significant population structure throughout the species' range. Similarly, after taking geographical distances into consideration, no statistically significant correlation between genomic distance and dissimilarity of bacterial assemblage was found, and the topologies of the genomic tree and clustering tree of microbial diversity were not concordant, showing that the factors that affect genomic structure in the host are not directly affecting their gut-associated microbiota. This study serves as a first stepping stone towards a better understanding of the role of gut-associated microbiota in Cape sea urchins and will help to enhance our understanding of the intricate relationships between marine organisms and their associated microbial communities.

Biodiversity patterns are shaped by the interplay between geodiversity and organismal characteristics. Superimposing genetic structure onto landscape heterogeneity (i.e., landscape genetics) can help to disentangle their interactions and better understand population dynamics. Previous studies on the sub-Antarctic Prince Edward Islands (located midway between Antarctica and Africa) have highlighted the importance of landscape and climatic barriers in shaping spatial genetic patterns and have drawn attention to the value of these islands as natural laboratories for studying fundamental concepts in biology. Here, we assessed the fine-scale spatial genetic structure of the springtail, Cryptopygus antarcticus travei, which is endemic to Marion Island, in tandem with high-resolution geological data. Using a species-specific suite of microsatellite markers, a fine-scale sampling design incorporating landscape complexity and generalised linear models (GLMs), we examined genetic patterns overlaid onto high-resolution digital surface models and surface geology data across two 1-km sampling transects. The GLMs revealed that genetic patterns across the landscape closely track landscape resistance data in concert with landscape discontinuities and barriers to gene flow identified at a scale of a few metres. These results show that the island's geodiversity plays an important role in shaping biodiversity patterns and intraspecific genetic diversity. This study illustrates that fine-scale genetic patterns in soil arthropods are markedly more structured than anticipated, given that previous studies have reported high levels of genetic diversity and evidence of genetic structing linked to landscape changes for springtail species and considering the homogeneity of the vegetation complexes characteristic of the island at the scale of tens to hundreds of metres. By incorporating fine-scale and high-resolution landscape features into our study, we were able to explain much of the observed spatial genetic patterns. Our study highlights geodiversity as a driver of spatial complexity. More widely, it holds important implications for the conservation and management of the sub-Antarctic islands. The interplay between geodiversity and organismal characteristics shapes biodiversity patterns and by superimposing genetic structure on landscape heterogeneity, one can disentangle these interactions to better understand population structure and dynamics. The sub-Antarctic Islands offer unique opportunities to study fundamental concepts in biology given their heterogeneous landscapes shaped by repeated large-scale volcanic and glacial events. The present study focuses on the springtail Cryptopygus antarcticus travei, a soil arthropod endemic to Marion Island and uses a species-specific suite of microsatellite markers and a fine-scale sampling design incorporating landscape complexity. This study illustrates that the fine-scale genetic patterns in soil arthropods are markedly more structured than anticipated, given the homogeneity of the vegetation complexes at the scale of tens to hundreds of metres. This work adds valuable new information to better understand the effects of local-scale landscape heterogeneity on the population genetic structure of the island's unique biota.image

Marine ecosystems are highly dynamic, and their connectivity is affected by a complex range of biological, spatial, and oceanographic factors. Incorporating connectivity as a factor in the planning and management of marine protected areas (MPAs) is important yet challenging. Here, we implemented a novel integrative framework that uses intraspecific genetic and genomic data for multiple marine species to characterise connectivity across a recently established South Australian MPA network. We generated connectivity networks, estimated cross-species concordance of connectivity patterns, and tested the impact of key spatial and oceanographic factors on each species. Connectivity patterns varied markedly among species, but were most correlated among those with similar dispersal strategies. Ordination analyses revealed significant associations with both waterway distances and oceanographic advection models. Notably, waterway distances provided better predictive power in all-species combined analyses. We extended the practical relevance of our findings by employing spatial prioritisation with Marxan, using node values derived from both genetic and geographic connectivity networks. This allowed the identification of several priority areas for conservation, and substantiated the initial decision to employ spatial distance as a proxy for biological connectivity for the design of the South Australian marine park network. Our study establishes a baseline for connectivity monitoring in South Australian MPAs, and provides guidelines for adapting this framework to protected networks elsewhere in the world.

Studies investigating gene flow in sessile or sedentary marine species typically draw conclusions about larval dispersal by investigating genetic structure of adults. Here, we generated microsatellite data from adults, recruits, settlers and planktonic larvae of the brown mussel, Perna perna, from the southeast coast of South Africa, and identified a consistent mismatch in genetic structure between the adults and all earlier life stages. While adults could be assigned to two major geographical groups (western and eastern), most of the early-stage mussels were strongly affiliated with the eastern group. This suggests that few of the early-stage individuals present in the western portion of the sampling range will eventually establish themselves in the adult population, highlighting the importance of post-recruitment processes as drivers of population structure. Our findings caution against the exclusive use of genetic data generated from adults to assess population connectivity facilitated by the dispersal of planktonic propagules.

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

Studying the early stages of the introduction of non-indigenous species (NIS) is crucial as it allows immediate management actions aimed at preventing NIS spread at a time when these actions are more likely to be effective. Recent species introductions present unique opportunities to study key aspects of the invasion process. However, comprehensive information on how and when NIS are first introduced remains rare. We assessed the characteristics of the introduction of a member of the widespread Pyura stolonifera species group (Chordata, Tunicata) in Europe. These ascidians are important bioengineer species that can attain amongst the highest benthic biomass per surface area ever reported. We collected introduced individuals on the coast of the northwestern Iberian Peninsula, an area with high shipping traffic and one of the world's most important mussel farming regions. The specimens were analysed using taxonomic and genetic tools. Both field surveys and taxonomic analysis showed that one of the African members of the species group, Pyura herdmani, has recently been introduced to Europe and, although it does not yet form the large aggregates found in the native range, it is already well-established. Genetic data revealed that only the northwest African lineage of P. herdmani has been introduced to Europe. Considering the low dispersal capabilities of the early life-history stages of P. herdmani, the introduction of this species into Europe can only be explained via human mediated transport of NIS. In order to prevent any detrimental effects on both native biota and/or economically-important anthropogenic activities, regular monitoring of recent NIS introductions is urgently required.

Understanding the genetic basis of local adaptation in thermal performance is useful for predicting species distribution shifts under anthropogenic climate change. Many species are distributed across multiple biogeographic regions, and the uniquely adapted populations in each region may respond to future ocean warming with distinct distribution changes. In the present study, we investigated phylogeographic patterns, thermal sensitivity, and genetic differentiation in the intertidal snail Littorina brevicula along China's coast. Whole-genome sequencing results based on a newly assembled chromosome-level genome revealed two genetic lineages, with a north-south divergence that is linked to the thermal environment. Within each lineage, individuals could be further subdivided into genetic subgroups that differ at key genomic loci underpinning differences in upper heat tolerance. Heat stress drives adaptive divergence across multiple levels of organization, from the individual to the biogeographic level. Taking into account genetic diversity associated with variation in heat tolerance, a physiological species distribution model (pSDM) was applied to predict the distributions of the different genetic subgroups in response to climate change. Both northern and southern lineages were predicted to experience declines in habitat suitability under a 4°C future warming scenario, and that a genotypic subset of snails from the southern lineage may even be driven to extinction. These findings illustrate that even when a species' range is maintained, it can nonetheless experience a significant decrease in adaptive diversity as a result of climate change. The integrated approach presented here, which considered both physiological and adaptive genetic variation at the level of individuals within a biogeographical context, provided new insights into how marine species can respond to global warming.

Background In genetics and evolutionary biology, the concept of selection signatures is used to describe specific patterns in the genome that are associated with the process of natural selection. This natural selection can leave distinct genetic footprints of signatures, such as changes in allele frequencies, the presence of specific mutations, or patterns of genetic variation. Selection signatures provide information about the evolutionary forces that have shaped a population over time. Methods In this study, a total of 96 samples from four different cattle breeds, namely Nguni (n = 28), Bonsmara (n = 21), Angus (n = 22), and Simmental (n = 25) were subjected to quality control, following quality control, a total of 105,675 SNPs from 73 individuals remained for further analysis. Genomic signatures of positive selection within each breed were identified using the Integrated Haplotype Score (iHS) method, and cross-population comparison analysis was conducted using XP-EHH, Rsb, and Fst methods to assess the genetic differences between breeds. Results For the iHS analyses of individual breeds, two genomic regions identified signatures of selection for Bonsmara, six for Simmental, four for Nguni, and one for Angus. Ten regions were identified as being under selection, with BTA 12 shared between Nguni and Bonsmara. Cross-population comparisons using XP-EHH, Rsb, and FST methods revealed specific genomic regions differentially selected between breeds. Gene annotation analyses revealed candidate genes associated with several Quantitative Trait Loci (QTL). For instance, in Simmental cattle, the gene FAM110B was associated with carcass weight and body confirmation score. Bonsmara cattle had fewer candidate genes, including CDK8 and FLT1, while Angus revealed no candidate genes on BTA 18. Nguni cattle revealed the following candidate genes CRB1, PLAG2GA, and VASH2, with CDK8 shared between Bonsmara and Nguni on BTA 12. Cross population comparisons further revealed candidate genes associated with specific traits. For Bonsmara vs Nguni, genes including PLCXD3, FAM149B1, and GRIK2 were identified, whereas, for Simmental vs Angus, SLIT2 and TSPAN9 genes were identified. Furthermore, the study highlighted gene functions, revealing associations with meat quality traits, reproduction, health, diseases, fertility, and body conformation score. Gene interaction analysis using the STRING database identified a network of 63 candidate genes, revealing the structure of genetic interactions. Some genes had multiple functions, indicating multiple roles in various biological processes. Conclusion This extensive genomic study can assist in highlighting the importance of the genetic background of breed-specific traits, and in this way contributes to selective breeding and trait improvement in cattle populations.

Temporary wetland ecosystems are common in arid and semi-arid environments, and are inhabited by diverse invertebrate communities. Little is known about the dynamics of genetic connectivity in the geographically scattered populations of these wetland specialists. The current study investigated the spatial genetic structure and dispersal history of a recently described calanoid copepod, Lovenula raynerae, reported from temporary wetlands in the Eastern Cape province of South Africa. We tested whether the species represents a single, well-connected population or comprises different regional genetic groups, some of which may be rare or endangered. Mitochondrial COI sequences were generated for 365 specimens from 46 temporary wetlands spread across the species' known distribution range. Isolation-by-distance and isolation-by-environment patterns of partitioning genetic variations across the landscape were evaluated. In addition, the presence of historical impediments to gene flow between contemporary populations was investigated using a combination of Monmonier's algorithm and Bayesian reconstruction of phylogeographical diffusion in continuous space. The wetland populations were highly structured across the landscape and could be assigned to six distinct evolutionary lineages, potentially representing some level of cryptic speciation. Two distinct phases were identified in the dispersal history of these lineages. Initially, dispersal only occurred inland of a postulated barrier, but eventually the barrier disappeared and the species extended its range by spreading into regions close to the coastline. Molecular dating shows that the barrier represents the upper limit of the coastline during the Pliocene, and that its crossing was facilitated by Pliocene sea regression in southern Africa. Our finding shows that complex demographic histories can be preserved in the mitochondrial DNA of temporary wetland crustaceans because of limited effective gene flow after initial colonisation events. This makes them an interesting study system to explore the long-term effects of climate change on arid ecosystem communities.

EDITORIAL article Front. Mar. Sci., 09 November 2023Sec. Marine Biology Volume 10 - 2023 | https://doi.org/10.3389/fmars.2023.1309683

Sampling:Transect sampling was conducted on eastern Marion Island at two sampling areas, namely Nellie Humps (NH) Skua Ridge (SR). The NH site included 24 sampling points separated from each other by a geographic distance ranging from 30 to 120 m, while the SR site comprised 21 sampling points separated by distances ranging from 60 and 190 m.Cryptopygus antarcticus travei specimens were collected by extracting them from sampled moss and/or ferns (approximately 10 cm3) using Berlese-Tullgren funnels. Twenty individuals of C. a. travei from each sampling point were identified and sorted using a compound light microscope, and stored in absolute ethanol (Merck, South Africa).Microsatellite genotyping:Whole genomic DNA was extracted using the DNeasy® Blood and Tissue Kit (Qiagen®, Hilden, Germany), according to the manufacturer's recommendations, with minor modifications that included a longer digestion step (overnight, but not more than 20 hours) and a reduced final elution volume (75 μl instead of 100 μl). Microsatellite loci were amplified in multiplex reactions (seven multiplex sets based on the criteria described by Rastorgueff et al., 2016) using 21 highly variable and species-specific markers (Rastorgueff et al., 2016), and fragment analysis was performed on a MultiGeneTM OptiMax Thermal Cycler (Applied Biosystems). Cleaned PCR amplicons were sized using the ABI Prism® 3500XL Genetic Analyser (Applied Biosystems, Foster City, California, USA). Alleles were analysed, scored, and binned manually using the Geneious v8.1.5 microsatellite plugin 1.4 (Kearse et al., 2012).The dataset added to the repository consists of the scored genotype data for all individuals from both sampling localities.

Understanding the dietary preferences of endangered species can be useful in implementing conservation strategies, including habitat restoration, translocation, and captive breeding. Environmental DNA (eDNA) from feces provides a non-invasive method for analysing animal diets. Currently, metabarcoding, a PCR-based approach, is the method of choice for analysing such data. However, this method has limitations, specifically PCR bias, which can result in the overestimation of the importance of certain taxa and failure to detect other taxa because they do not amplify. The present study compared metabarcoding with metagenomics, a PCR-free method, to assess the diversity of prey items in the feces of a critically endangered South African estuarine pipefish, Syngnathus watermeyeri , and its widely distributed congener S. temminckii to investigate potential dietary competition. The metabarcoding results showed a distinct difference between the diets of S. watermeyeri and S. temminckii , with the former mainly consuming calanoid copepods and the latter preferring caridean shrimp. In each case, a single species dominated the sequences generated by metabarcoding. Metagenomics produced more species identifications, and although the same trend was found regarding the preference of S. watermeyeri for copepods and that of S. temminckii for shrimp, this approach identified additional, albeit yet unidentified, copepod species as being important in the diet of S. watermeyeri . We conclude that the lower number of species identified using metabarcoding was most likely a result of amplification bias, resulting in key copepod species missing from the dietary analysis. These findings suggest that metagenomics is not only a useful complementary method for molecular dietary analysis, but may in some cases outperform metabarcoding. However, metagenomics is even more strongly affected by the lack of reference sequences than is metabarcoding, as the majority of sequences originate from genomic regions that have not yet been sequenced for the putative prey species in question.

Seagrass habitats are declining worldwide, placing several seagrass-associated animals at risk of extinction. The Critically Endangered limpet Siphonaria compressa is one of the rarest molluscs in Africa, and has been reported from only two disjunctive lagoons in South Africa. Being a highly specialized grazer that lives exclusively on the narrow blades of Cape eelgrass, Zostera capensis, which is itself listed as Endangered in the South African Red List and has decreased in abundance, conservation initiatives are urgently needed to ensure the long-term survival of S. compressa.Molecular data (sequence data from the mitochondrial genome and single nucleotide polymorphism data of the nuclear genome) and morphological data were analysed to determine whether the two populations are conspecific, with implications for whether translocation between localities could be a viable management strategy to restore either population in the event of a collapse, or to maintain the genetic diversity of each population.Strong evidence emerged for the distinctness of the two populations, including a lack of shared mtDNA haplotypes that indicate an absence of contemporary gene flow, a divergence time that dates to the late Pleistocene, and a number of morphological characters that distinguish their shells. These findings indicate that the two populations are distinct cryptic subspecies.As the two populations occur in different temperature-defined marine biogeographical regions, they are probably adapted to different thermal environments. Translocations are not recommended, as this management strategy has considerable potential to result in outbreeding depression and exacerbate the extinction risk. Instead, each population should be managed separately, and several alternative conservation measures are discussed, including the protection and restoration of seagrass beds.

Background The Octopus vulgaris species complex consists of numerous morphologically similar but genetically distinct species. The current publicly available mitogenome of this species has been generated from a specimen collected from Tsukiji Fish Market, Tokyo, Japan. Octopus from the northwestern Pacific Ocean are now considered to be a separate species, Octopus sinensis . For this reason, we hypothesised that the current record of O. vulgaris was sequenced from a specimen of O. sinensis . Here, we sequenced the first complete mitogenome of a specimen of Octopus vulgaris sensu stricto that was collected from the species’ confirmed distribution areas in northeastern Atlantic. Methods and results The complete mitogenome was assembled de novo and annotated using 250 bp paired-end sequences. A single circular contig 15,655 bp in length with a mean read coverage of 1089 reads was reconstructed. The annotation pipeline identified 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNA) and two ribosomal RNAs. A maximum likelihood phylogenetic tree recovered the assembled mitogenome as the sister taxon of a monophyletic group comprising O. sinensis and the previously published mitogenome of “ O. vulgaris ” from Japan. This confirms that the latter was a Japanese specimen of O. sinensis . Conclusion The mitogenome sequenced here is the first to be published for Octopus vulgaris sensu stricto. It represents an important first step in genetics-informed research on the evolution, conservation, and management of this commercially important species.