Catsharks (family Scyliorhinidae) and the recently reclassified deepwater catsharks (family Pentanchidae) are two of the largest families of elasmobranchs and include species that function as important mesopredators in almost all marine ecosystems. This study focuses on four species endemic to the coast of southern Africa: the puffadder shyshark Haploblepharus edwardsii, dark shyshark H. pictus, leopard catshark Poroderma pantherinum and pyjama catshark P. africanum. Similar to most catsharks, these four species are underrepresented in chondrichthyan research. Our investigation aimed to gain insight into the distribution and site fidelity of the focal species through mark-recapture efforts in Walker Bay on the southwest coast. The use of 95% minimum convex polygons indicated large overlaps in distribution among the species as well as between sexes, except for H. edwardsii. Site fidelity was universally low (0.005) at three key sample sites, although travel distances between sites averaged 3–5.5 km across all species. The results suggest that sexual segregation is not present for the studied catshark species, with the possible exception of H. edwardsii, which had a low capture rate. The low levels of site fidelity and movement also indicated significant levels of site interconnectivity between the three commonly sampled sites as they fell within the same 5-km2 region of the bay. From the present findings, Walker Bay could be considered an area of interest for conservation with respect to the four species, allowing for further study of their population dynamics and the influence of the local marine protected area.

Adaptive divergence in response to environmental clines are expected to be common in species occupying heterogeneous environments. Despite numerous advances in techniques appropriate for non‐model species, gene–environment association studies in elasmobranchs are still scarce. The bronze whaler or copper shark (Carcharhinus brachyurus) is a large coastal shark with a wide distribution and one of the most exploited elasmobranchs in southern Africa. Here, we assessed the distribution of neutral and adaptive genomic diversity in C. brachyurus across a highly heterogeneous environment in southern Africa based on genome‐wide SNPs obtained through a restriction site‐associated DNA method (3RAD). A combination of differentiation‐based genome‐scan (outflank) and genotype–environment analyses (redundancy analysis, latent factor mixed models) identified a total of 234 differentiation‐based outlier and candidate SNPs associated with bioclimatic variables. Analysis of 26,299 putatively neutral SNPs revealed moderate and evenly distributed levels of genomic diversity across sites from the east coast of South Africa to Angola. Multivariate and clustering analyses demonstrated a high degree of gene flow with no significant population structuring among or within ocean basins. In contrast, the putatively adaptive SNPs demonstrated the presence of two clusters and deep divergence between Angola and all other individuals from Namibia and South Africa. These results provide evidence for adaptive divergence in response to a heterogeneous seascape in a large, mobile shark despite high levels of gene flow. These results are expected to inform management strategies and policy at the national and regional level for conservation of C. brachyurus populations.

The spotted gully shark Triakis megalopterus (Triakidae) is a mesopredatory species endemic to southern Africa. It is currently listed as Least Concern on the IUCN Red List in accordance with an estimated increase in population size, general release by recreational linefishers and incidental catches in the commercial linefisheries. Previous research suggests this species to be resident, and as such it is likely to receive protection in coastal marine protected areas (MPAs). However, its ecology and movement behaviour remain poorly studied. This study employed acoustic telemetry to provide information on the species’ movements along the coast of the Western Cape Province, South Africa. We used network analyses to investigate movement randomness, associations between individuals, sexual segregation, and the effectiveness of MPAs. Our findings reveal nonrandom movements as well as patterns of co-occurrence between individuals. Spatial network analysis suggested sexual segregation, because areas of high use (Walker Bay and De Hoop) differed between males and females. Co-occurrences were observed exclusively in Walker Bay, chiefly between males, with no co-occurrence found between females. The tagged spotted gully sharks were not detected extensively within existing MPA boundaries, though there was no significant difference between their movements inside and outside protected areas for both sexes.

The pyjama shark (Poroderma africanum) is a Scyliorhinid species endemic to South Africa. Even though it is kept in captivity in many aquaria, there is a lack of research on its growth and development. In this study, we investigated the fertilization rate of eggs and the age at female sexual maturation in captive sharks and compared their growth to that of wild individuals. This is the first study to compare the growth of captive and wild catsharks as well as the first study to compare growth in male and female pyjama sharks and benefits from a much larger sample size than has previously been collected. The mean incubation rate (±standard error of the mean [SE]) was 239.46 ± 4.97 days, the mean Lt of hatchlings (±SE) was 14.65 ± 0.24 cm, and the mean Wt (±SE) was 17.19 ± 0.75 g. The observed ratio of male to female offspring (1:3.5) was also significantly different from 1:1. One female laid fertilized eggs 6.6 years after hatching and was considered sexually mature. Both in captivity and in the wild, males showed negative allometric growth and females showed isometric growth. The growth performance (Φ') was also greater in captive sharks compared to wild sharks regardless of sex. However, there was significant variation in growth between individuals of the same sex. The similar growth patterns (i.e., allometry and isometry) found in wild and captive populations are a very useful tool for informing future conservation management if the population of this shark species were to decline in the future and also prove that captive studies for this species are transferable to wild populations with regard to sexual differences. This study also provides a benchmark for further captive studies in other lesser‐studied catshark species and raises interesting questions concerning sexual differences in growth for other shark species.

The International Union for Conservation of Nature (IUCN) estimates that over a third of all chondrichthyan species (sharks, rays and chimaeras) are threatened with extinction, primarily by overfishing (as target or bycatch species). Owing to the wide-ranging distributions of many chondrichthyans, they are often overlooked in marine protected area (MPA) design. South Africa is a biodiversity hotspot for chondrichthyan species diversity, and to improve the conservation status of these species in the country's continental exclusive economic zone (EEZ), we collaborated widely to collate existing occurrence data. Ensemble models were developed for 87 species' distributions, which informed a systematic conservation planning analysis for 64 threatened and endemic species. We assessed the current representation of these species in South Africa's MPA network and identified priority areas for protection, avoiding fishing pressure where possible. Results show that many MPAs are well placed to protect chondrichthyans, especially along the east coast (KwaZulu-Natal province). Unfortunately, permissive fishing regulations within many MPA zones reduces their effectiveness at protecting chondrichthyans. Improved regulations designed to protect chondrichthyans within all MPAs should be considered a high priority. Priority areas for increased spatial protection were identified along the west coast continental shelf, the Agulhas Bank off the south coast, and south coast embayments. We found that supplementing the current MPA network by an additional 5 % of the EEZ would be sufficient to protect >30 % of the range of all 64 species, provided there is adequate enforcement. As South Africa prepares to expand its MPA estate to meet international targets, these findings can ensure that chondrichthyans are well represented.