Ctenostome bryozoans pose ongoing challenges for taxonomists and systematists, owing to their lack of character-rich mineralized skeletons. We present the largest (super)family-level phylogeny of Ctenostomatida to date. We resolved the three major clades (A–C) that were recognized previously. Clade A included endolithic taxa Penetrantiidae, Immergentiidae, and Terebripora ramosa, the latter two being sister taxa. Other taxa in this clade were Nolella, Arachnidium, Pottsiella, and Paludicella. Clade B was composed of Alcyonidioidea and Multiporata. The genus Alcyonidium was revealed as non-monophyletic, with the two recovered clades likely to be characterized by contrasting reproductive modes (brooding and zygote spawning). Members of the presumptive brooding clade had insertions of possible exogenous origin in their 18S and 28S ribosomal RNA genes, which might be the result of horizontal gene transfer. Clade C was sister to the Cheilostomatida and was composed of Vesicularioidea, Hislopioidea, Walkerioidea, and three clades of Victorellidae. Anguinella and Hypophorella were consistently sister taxa, but their position was unstable. Results are discussed in light of morphology, reproduction, and previous phylogenetic hypotheses. A revised classification is proposed. Timwoodiellina natans is transferred to Hislopia, Vesicularia spinosa to Amathia, and Monobryozoon ambulans to Alcyonidium. Members of the putative zygote-spawning Alcyonidium clade are transferred to Alcyonidioides in the family Alcyonidioididae.

The main aim of this study was to investigate whether environmental or biological factors predominantly influence bryozoan biomineralization along the South African coast (spanning from 29.263°S; 16.87°E to 27.540°S; 32.677°E), a region known for its diverse oceanographic conditions. New data into the mineralogical (calcite vs. aragonite) and geochemical (Mg content in calcite) composition of bryozoans are provided, enhancing the global database and understanding of biomineralization patterns. To date, there has been a notable scarcity of data on bryozoan skeletal composition in tropical and subtropical regions, representing a significant gap in our knowledge and understanding of the impacts of climate change on marine, calcifying organisms. Our research reveals a diverse array of carbonate skeletons across nearly half of the known bryozoan species in the region, with calcitic forms dominating, followed by bimineralic and aragonite-based forms. The prevalence of aragonite-containing skeletons, particularly within the Cheilostomatida, mirrors global patterns, indicating a correlation with sea temperature gradients. Significant mineralogy and magnesium calcite variability exists within the Flustrina and Membraniporina suborders (Cheilostomatida). Despite exploring various environmental parameters such as temperature, salinity, or impact of currents (Agulhas, Benguela, or mixed), no clear correlation with mineralogical patterns emerged. Instead, the study underscores the substantial influence of biological control on bryozoan skeletal carbonate mineralogy and geochemistry. These findings highlight the importance of comprehensive, multi-parametric analyses to unravel environmental signals in bryozoan biomineralization, contributing to a deeper understanding of the impacts of climate and local conditions on marine calcifiers.

AimQuantify the contribution of environmental factors (water temperature, salinity and depth) and evolutionary history to varied skeletal mineralogy in calcifying marine organisms.LocationGlobal Ocean.Time periodPresent.Major taxa studiedOrder: Cheilostomatida; Phylum: Bryozoa.MethodsWe employed X-ray diffraction (XRD) to analyse the skeletal mineral composition of 872 individual colonies, representing 437 bryozoan species, in terms of calcite/aragonite ratios. We integrated these data with equivalent published data, thus reaching 981 species, and applied linear models (LMs), generalized linear models (GLMs) and phylogenetic generalized least squares models (PGLSs) to investigate the influences of temperature, salinity, depth and phylogenetic history on the mineralogy of nearly 1000 cheilostome bryozoan species.ResultsCheilostome bryozoans vary considerably in their skeletal mineral composition: in our dataset 65% of the species possess purely calcite skeletons, 15% exclusively employ aragonite and 20% exhibit mixed (i.e. calcite and aragonite) mineralogies. Temperature is the predominant measured environmental factor influencing bryozoan skeletal mineralogy, accounting for 20% of its variability across species, when phylogenetic relatedness is unaccounted for. Bryozoans in lower latitudes, characterized by higher seawater temperatures, have higher aragonite concentrations. By accounting for phylogenetic structure using a subset of 87 species for which we have topological information, 40% of the observed mineralogical variability could be attributed to present-day temperature. In contrast, depth and salinity played minor roles, explaining less than 1% of the mineralogical variation each.Main conclusionsThis study emphasizes the influence of evolutionary history on the mineralogical variability of calcifying organisms, even when it can be shown that a single environmental factor (temperature) explains a substantial amount of this variability. When confronted with changing temperature, calcifiers such as bryozoans are likely to respond in diverse ways, depending on the species, given their phylogenetic relatedness and the external conditions they meet.

Parental care is considered crucial for the enhanced survival of offspring and evolutionary success of many metazoan groups. Most bryozoans incubate their young in brood chambers or intracoelomically. Based on the drastic morphological differences in incubation chambers across members of the order Cheilostomatida (class Gymnolaemata), multiple origins of incubation were predicted in this group. This hypothesis was tested by constructing a molecular phylogeny based on mitogenome data and nuclear rRNA genes 18S and 28S with the most complete sampling of taxa with various incubation devices to date. Ancestral character estimation suggested that distinct types of brood chambers evolved at least 10 times in Cheilostomatida. In Eucratea loricata and Aetea spp. brooding evolved unambiguously from a zygote-spawning ancestral state, as it probably did in Tendra zostericola, Neocheilostomata, and 'Carbasea' indivisa. In two further instances, brooders with different incubation chamber types, skeletal and non-skeletal, formed clades (Scruparia spp., Leiosalpinx australis) and (Catenicula corbulifera (Steginoporella spp. (Labioporella spp., Thalamoporella californica))), each also probably evolved from a zygote-spawning ancestral state. The modular nature of bryozoans probably contributed to the evolution of such a diverse array of embryonic incubation chambers, which included complex constructions made of polymorphic heterozooids, and maternal zooidal invaginations and outgrowths.

PHYLOGENIES All_genes_alignment.nex The concatenated mixed alignment consisting of, 13 mitochondrial protein-coding genes as amino acids, mitochondrial ribosomal RNA genes 12S+16S, and nuclear 18S+28S rRNA genes. Gene boundaries and excludes sites are indicated. Fig_2.nex Topology of the Bayesian phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. The analysis was performed in MrBayes5D v. 3.2.6 under the GTR+G model of nucleotide evolution (nucleotides) and the MTZOA+G model (amino acids). The analysis was run for 2.4 million generations; 1.5 million generations were discarded as burn-in. Fig_S3 Topology of the Bayesian phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes (PCGs) as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. The analysis was performed in p4 under the GTR+G model of nucleotide evolution (nucleotides) and the MTZOA+G+F model (amino acids). The +F model component accommodates empirical composition in the amino acid model. The analysis used three separate runs for 300,000 generations; 200,000 generations were discarded as burn-in. Fig_S4 Topology of the maximum likelihood phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. The analysis was performed in RAxML HPC-PTHREADS-SSE3 v. 8.2.12 under the GTR+G (nucleotides) and the MTZOA+G+F models (amino acids). Fig_S5 Topology of the Bayesian phylogenetic analysis of the 12S+16S rRNA gene partition constructed using MrBayes v. 3.2.6 under the GTR + G model. The analysis was run for 20 million generations; 10 million generations were discarded as burn-in. Fig_S6 Topology of the maximum likelihood phylogenetic analysis of the 12S+16S rRNA gene partition constructed using RAxML HPC-PTHREADS-SSE3 v. 8.2.12 under the GTRCAT model. Fig_S7 Topology of the Bayesian phylogenetic analysis of the 18S+28S rRNA gene partition constructed using MrBayes v. 3.2.6 under the GTR + G model. The analysis was run for 20 million generations; 10 million generations were discarded as burn-in. Fig_S8 Topology of the maximum likelihood phylogenetic analysis of the 18S+28S rRNA gene partition constructed using RAxML HPC-PTHREADS-SSE3 v. 8.2.12 under the GTRCAT model. Fig_S9 Topology of the Bayesian phylogenetic analysis of 13 mitochondrial protein-coding genes as amino acids constructed using MrBayes5D v. 3.2.6 under the MTZOA+G model. The analysis was run for 3.7 million generations; 2.5 million generations were discarded as burn-in. Fig_S10 Topology of the maximum likelihood phylogenetic analysis of 13 mitochondrial protein-coding genes as amino acids constructed using RAxML HPC-PTHREADS-SSE3 v. 8.2.12 under the PROTGAMMAMTZOA model. Fig_S11 Topology of the Bayesian phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes (PCGs) as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. The analysis was performed in p4 under the NDCH-C2 model. The analysis used four separate runs for 300,000 generations; 200,000 generations were discarded as burn-in. The NDCH model accommodates compositional tree-heterogeneity and was used because there was a large amount of compositional heterogeneity over the sequences, especially in the PCGs and 12S+16S rRNA data partitions. This is an NDCH model with two composition vectors on each of the three data partitions. Fig_S12 Topology of the Bayesian phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. This analysis excluded all terminals for which less than half of mitogenome genes were available, or which only had one of the two nuclear rRNA genes. The analysis was performed in MrBayes5D v. 3.2.6 under the GTR+G model of nucleotide evolution (nucleotides) and the MTZOA+G model (amino acids). The analysis was run for 350,000 generations; 125,000 generations were discarded as burn-in. Fig_S13 Topology of the maximum likelihood phylogenetic analysis of the mixed concatenated alignment consisting of three partitions: (i) 13 mitochondrial protein-coding genes as amino acids, (ii) mitochondrial ribosomal RNA genes 12S+16S, (iii) nuclear 18S+28S rRNA genes. This analysis excluded all terminals for which less than half of mitogenome genes were available, or which only had one of the two nuclear rRNA genes. The analysis was performed in RAxML HPC-PTHREADS-SSE3 v. 8.2.12 under the GTR+G (nucleotides) and the MTZOA+G+F models (amino acids). ANCESTRAL CHARACTER ESTIMATION: ACE.R R script of the ancestral character estimation carried out in phytools. Reproductive_strategy_numbers.csv Data input file for ACE analysis (reproductive strategies coded as numbers) Reproductive_strategies.xlsx List of reproductive strategies per taxon with the corresponding numerical codes used in the file 'Reproductive_stategies_numbers.csv'. Tree.tre Input tree for ACE analysis.

Originating from the Second International Indian Ocean Expedition (IIOE-2), the main goal of the Western Indian Ocean (WIO) Regional Benthic Imagery Workshop, was to provide information and training on the use of various underwater imagery platforms in benthic research. To date, attempts made to explore the bottom of the ocean range from simple diving bells to more advanced camera systems, and the rapidly expanding field of underwater image-based research has supported marine exploration in many forms, from biodiversity surveys, spatial analyses and temporal studies, to monitoring schemes. Alongside the increasing use of underwater camera systems worldwide, there is an evident need to improve training and access to these techniques for students and researchers from institutes within the WIO. The week-long virtual event was conducted between 30 August and 3 September 2021 with 266 participants. Sessions consisted of lessons, practical demonstrations and interactive discussions which covered the steps required to conduct underwater imagery surveys, taking participants through elements of sampling design, data acquisition and processing, considerations for statistical analysis and, effective managment of data. The session recordings from the workshop are available online as a teaching aid which has the potential to reach marine researchers both regionally and globally. It is crucial that we build on this momentum by continuing to develop and strengthen the network established through this initiative for standardised benthic-image-based research within the WIO.

Phylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c. 500 cheilostome species. We find that named cheilostome genera and species are phylogenetically coherent, rendering fossil or contemporary specimens readily delimited using only skeletal morphology. Our phylogeny shows that parental care in the form of brooding evolved several times independently but was never lost in cheilostomes. Our fossil calibration, robust to varied assumptions, indicates that the cheilostome lineage and parental care therein could have Paleozoic origins, much older than the first known fossil record of cheilostomes in the Late Jurassic.

For most marine scientists, unless we work in the field of fisheries development or at the interface of science and policy, it is rare to feel that we are making an impact on the lives of people in the wider community.Most research scientists at universities and government laboratories also have limited opportunity to engage with schools and the general public outside of once-a-year open days.But beyond the science and networking, conferences, especially international conferences, can provide a myriad of opportunities for us to redress both these issues in a way that enriches all.Here, we describe the programme of development-related activities that supported the 6th International Jellyfish Blooms Symposium, and their impact, and we urge it be used as a template for other scientific meetings in the future.Jellyfish are far more than merely an interesting find on the beach.On the one hand, when abundant, jellyfish can cause economic harm to the tourism, aquaculture, fisheries and energy sectors 1 , but on the other hand, they provide food for other animals, e.g.turtles, shelter for juvenile fish and a potential resource to exploit 2 .In recognition of their role in marine ecosystems, the international jellyfish community updates and renews itself at a conference every 3 years or so.The first meeting was held in the USA in January 2000 and after conferences in Australia, Argentina, Japan and Spain, Africa's turn came in 2019, after Monty Graham (University of Southern Mississippi) convinced one of us (M.J.G.) to host the conference at the University of the Western Cape.'Whilst Africa may have witnessed the evolution of Homo sapiens sapiens, she is nevertheless young and inexperienced … in so many ways.Consequently, the conference will focus on development in its broadest sense…'.These sentences open paragraph two on the conference webpage (http://www.jellyfishbloom2019.co.za), and effectively encapsulated our thoughts on both the science programme and ancillary activities.

Non-studied museum collections are hidden treasures—a source of information for various research fields. The novel taxa presented here were discovered during taxonomic examination of the backlogs of Bryozoa (Cheilostomata) from the Iziko South African Museum. We describe one new genus, Khulisa n. gen., and nine new species of bryozoans from South Africa. The new species are: Biflustra adenticulata n. sp., Aspidostoma sarcophagus n. sp., ?Micropora erecta n. sp., Trypostega richardi n. sp., Khulisa carolinae n. gen. et n. sp., Adeonella assegai n. sp., Hippomonavella lingulata n. sp., Phidolopora chakra n. sp. and Reteporella ilala n. sp. Three genera, Biflustra, Phidolopora and Triphyllozoon, are recorded for the first time from South Africa. This study highlights the importance of examining existing backlogged material lodged in museum collections.

The zoogeography of marine Bryozoa around South Africa was investigated using published distribution records, museum catalogues, and an examination of previously unworked bryozoan material in (mostly) museum collections. Although a total of 276 valid species are recognised, it was not possible to unambiguously assess geographic patterns of diversity. At all depth zones examined (shore and inner-shelf, 0–30 m; mid- and outer-shelf, 31–350 m; bathyal, >500 m), there was a clear geographic structure to communities that mirrored established regional patterns of biogeography. Too few samples were collected from the shelf edge (351–500 m) and they were consequently excluded from zoogeographic analysis. Communities on the shore and inner-shelf and on the mid- and outer-shelf were more similar to each other than they were to bathyal communities, and the pronounced structure in bathyal communities suggests heterogeneity in the deep sea around South Africa.

BACKGROUND:Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes. Here, we use a genome-skimming approach to extract sequence information for 15 mitochondrial and 2 ribosomal operon genes from the cheilostome bryozoan family, Adeonidae, Busk, 1884, whose current systematics is based purely on morphological traits. The members of the Adeonidae are, like all cheilostome bryozoans, benthic, colonial, marine organisms. Adeonids are also geographically widely-distributed, often locally common, and are sometimes important habitat-builders.RESULTS:We successfully genome-skimmed 35 adeonid colonies representing 6 genera (Adeona, Adeonellopsis, Bracebridgia, Adeonella, Laminopora and Cucullipora). We also contributed 16 new, circularised mitochondrial genomes to the eight previously published for cheilostome bryozoans. Using the aforementioned mitochondrial and ribosomal genes, we inferred the relationships among these 35 samples. Contrary to some previous suggestions, the Adeonidae is a robustly supported monophyletic clade. However, the genera Adeonella and Laminopora are in need of revision: Adeonella is polyphyletic and Laminopora paraphyletically forms a clade with some Adeonella species. Additionally, we assign a sequence clustering identity using cox1 barcoding region of 99% at the species and 83% at the genus level.CONCLUSIONS:We provide sequence data, obtained via genome-skimming, that greatly increases the resolution of the phylogenetic relationships within the adeonids. We present a highly-supported topology based on 17 genes and substantially increase availability of circularised cheilostome mitochondrial genomes, and highlight how we can extend our pipeline to other bryozoans.

Twelve species of deep-water cheilostome Bryozoa are reported from an incidental deep-water collection from the south coast of South Africa. The collection represents nine families and ten genera. One species, Arthropoma lioneli sp. nov., is new to science. The results reinforce the need for targeted sampling of South Africa's poorly known deep-water benthic fauna to assist the assignment of offshore marine protected areas within its Exclusive Economic Zone. With the addition of the new species, the bryozoan fauna of South Africa comprises no fewer than 271 valid marine species.

A new species of Escharinidae, Taylorius nyembezi sp. nov., is described and illustrated from material collectedby the R.V. Meiring Naude cruises at 90 m depth off the east coast of South Africa in 1979 and lodged in the collections of the Iziko Museums of South Africa, Cape Town and The Natural History Museum, London. The specimens were previously reported as conspecific with recent and fossil specimens from New Zealand and misidentified as Escharina waiparaensis (Brown, 1952) by Hayward & Cook (1983). Subsequently Gordon (2014) clarified the taxonomic status of the unique species that constitutes Escharina waiparaensis. In this paper we erect Taylorius nyembezi sp. nov., for the South African specimens based on its unique anter and sinus shape, metrics of its zooids and orifices, and the large size and position of the spine bases.

Cyclostomes are an ancient order of marine bryozoans with a fossil record extending back over 450 million years into the Ordovician. The current taxonomy of both fossil and modern cyclostomes is based almost entirely on skeletal characters but newly available sequence data are beginning to reveal rampant convergence of some of them. An unusual combination of skeletal characters in the South African cyclostome Tennysonia stellata Busk, 1867 has made this genus difficult to classify. After revising the taxonomy of Tennysonia, we use almost complete small and large ribosomal subunits (ssrDNA and lsrDNA) to demonstrate its close phylogenetic affinity with the tubuliporine genus Idmidronea (family Tubuliporidae) with which it shares a similar colony form, despite the presence of skeletally open kenozooids between the autozooids, reminiscent of cerioporine cyclostomes such as Favosipora. The spaces between the transverse rows of autozooidal apertures, occupied by exterior autozooidal frontal walls in Idmidronea, are occupied by kenozooids in Tennysonia, thereby maintaining the spacing between lophophores necessary for efficient suspension feeding. Sympatric colonies of T. stellata with narrow and broad branches are identical or almost identical on the basis of ssrDNA and lsrDNA sequences, respectively, suggesting within-species ecophenotypic plasticity in this aspect of colony form.

A new species of Magelonidae, Magelona debeerei sp. nov., is described and illustrated from grab-samples collected at <100 m off the southwest coast of Africa. Magelona debeerei sp. nov. has previously been identified from the region as M. papillicornis (Muller, 1858) by Day (1955, 1961, 1967) but differs from M. papillicornis sensu stricto by possessing dorsal medial lobes on chaetigers 4-8 and lateral pouches (Sigma configuration) between chaetigers 10 and 11. Three species of Magelona have now been recorded from southern Africa (M. capensis Day, 1961, M. cincta Ehlers, 1908 and M. debeerei sp. nov.), and a key to Magelona from this region is provided.

Sixty-three species of shallow-water Bryozoa, from 12 localities along the west coast of South Africa, are described and represent three orders (Cyclostomata, Ctenostomata and Cheilostomata), 33 families and 46 genera. Five species are cyclostomes, three are ctenostomes and 55 are cheilostomes. The relative dominance of the Cheilostomata is not surprising considering the relatively low diversity of cyclostomes and ctenostomes in marine habitats. Of the 63 species, 48 are redescribed from current material. Fifteen species (namely Eurystrotos planus, Membranipora rustica, Chaperia septispina, Klugeflustra jonesii, Bicellariella bonsai, Beania minuspina, Micropora latiavicula, Thalamoporella spiravicula, Escharoides custodis, Bitectipora umboavicula, Schizosmittina lizzya, Microporella madiba, Fenestrulina elevora, Celleporina solida and Rhynchozoon abscondum) are new to science, of which seven are found in seven genera (Eurystrotos, Klugeflustra, Thalamoporella, Bitectipora, Schizosmittina, Fenestrulina and Celleporina) that are newly recorded from South Africa. Thirteen species are recorded from the west coast for the first time, one of which, Hippomonavella formosa, is a new record for South Africa. Including the species described here, approximately 270 valid species, representing three orders (Cyclostomata, Ctenostomata and Cheilostomata), 74 families, and 130 genera have been recorded from South Africa. An accurate species number is not yet possible from this region as there are still outstanding problems with synonymies.