Kingklip, Genypterus capensis, is a valuable fish resource in southern African waters, with a wide geographic distribution spanning South Africa and Namibia. Previous studies have provided evidence for multiple stocks in South Africa, but the extent of stock structuring across the southern Africa region remains unclear. In this study we genotyped over 40,000 SNPs to characterize the spatial distribution of genomic variation for G. capensis throughout its core distribution. Results suggest that fish sampled at the northernmost range (off central Namibia) are characterized by lower genomic diversity, although the region exhibited the highest number of private SNPs, suggesting some degree of geographic isolation. Using neutral and putative outlier loci independently, we show that kingklip exhibits three population clusters, "northern Benguela," "southern Benguela," and South African "South Coast." Population differentiation was observed only using putative outlier loci, suggesting that local adaptation might be one of the main drivers of the observed differentiation. Overall, our research provides novel insights into the regional dynamics that can support the sustainable long-term exploitation of this valuable fisheries resource.

No abstract

No abstract

Fishes belonging to the family Clinidae in South Africa display super-embryonation, a rare reproductive mode were females gestate broods at different gestational stages, but little is known regarding the mating systems of this family. Here we tested the hypothesis that multiple males would contribute not only to the offspring of each female, but that several males would contribute to each brood, by sampling Muraenoclinus dorsalis from three sampling locations along the west and south-west coast of South Africa. Larval (n = 97) and maternal (n = 14) genotpyes, generated with newly developed microsatellites, were used to estimate the number of potential mates per female. Our results show that up to 78% of females displayed multiple mating with an average of 2·1-2·2 males. In addition, 39-42% of females displayed polyandry with an average of 1·5-1·6 sires per brood. This study provides the evidence for multiple mating and polyandry within a clinid fish characterized by super-embryonation that offers important baseline information regarding rare reproductive strategies, highlighting several gaps in our knowledge concerning clinid reproduction and mating systems.

The critically endangered hawksbill sea turtle (Eretmochelys imbricata) is of conservation concern worldwide. Conservation actions which act to reduce high levels of embryonic mortality aid to boost hatchling production. At Cousine Island, Seychelles, a mixed management method has been adopted to maximize the number of hatchlings entering the ocean. We examined the effectiveness of a hatchery at increasing hatching and emergence success from four seasons of data (2017–2021). Hatchery nests had significantly higher hatching and emergence success across all years relative to nests left in situ (i.e., natural), with inter‐annual variation observed. A greater percentage of in situ clutches was found to be influenced by both crab activity and predation as compared to relocated clutches. Overall, the mixed management approach increased hatching success (mean = 75.1%) relative to the various nest management techniques previously used (2004/2005–2016/2017; mean = 63.5%). By mitigating external influences such as tidal flooding, beach erosion, and crab activity/predation, this study provides evidence for the success of a hatchery in directly increasing hatchling recruitment. Strict and careful hatchery management as well as timely and efficient relocation procedures are needed to minimize potential negative effects of nest relocation.